diff --git a/parakeet/audio/__init__.py b/parakeet/audio/__init__.py
new file mode 100644
index 0000000..6212dee
--- /dev/null
+++ b/parakeet/audio/__init__.py
@@ -0,0 +1 @@
+from .audio import AudioProcessor
\ No newline at end of file
diff --git a/parakeet/audio/audio.py b/parakeet/audio/audio.py
new file mode 100644
index 0000000..6b84701
--- /dev/null
+++ b/parakeet/audio/audio.py
@@ -0,0 +1,261 @@
+import librosa
+import soundfile as sf
+import numpy as np
+import scipy.io
+import scipy.signal
+
+class AudioProcessor(object):
+    def __init__(self,
+                 sample_rate=None, # int, sampling rate
+                 num_mels=None, # int, bands of mel spectrogram
+                 min_level_db=None, # float, minimum level db
+                 ref_level_db=None, # float, reference level db
+                 n_fft=None, # int: number of samples in a frame for stft
+                 win_length=None, # int: the same meaning with n_fft
+                 hop_length=None, # int: number of samples between neighboring frame
+                 power=None, # float:power to raise before griffin-lim
+                 preemphasis=None, # float: preemphasis coefficident
+                 signal_norm=None, # 
+                 symmetric_norm=False, # bool, apply clip norm in [-max_norm, max_form]
+                 max_norm=None, # float, max norm
+                 mel_fmin=None, # int: mel spectrogram's minimum frequency
+                 mel_fmax=None, # int: mel spectrogram's maximum frequency
+                 clip_norm=True, # bool: clip spectrogram's norm
+                 griffin_lim_iters=None, # int:
+                 do_trim_silence=False, # bool: trim silence
+                 sound_norm=False,
+                 **kwargs):
+        self.sample_rate = sample_rate
+        self.num_mels = num_mels
+        self.min_level_db = min_level_db
+        self.ref_level_db = ref_level_db
+
+        # stft related
+        self.n_fft = n_fft
+        self.win_length = win_length or n_fft
+        # hop length defaults to 1/4 window_length
+        self.hop_length = hop_length or 0.25 * self.win_length 
+        
+        self.power = power
+        self.preemphasis = float(preemphasis)
+
+        self.griffin_lim_iters = griffin_lim_iters
+        self.signal_norm = signal_norm
+        self.symmetric_norm = symmetric_norm
+
+        # mel transform related
+        self.mel_fmin = mel_fmin
+        self.mel_fmax = mel_fmax
+
+        self.max_norm = 1.0 if max_norm is None else float(max_norm)
+        self.clip_norm = clip_norm
+        self.do_trim_silence = do_trim_silence
+
+        self.sound_norm = sound_norm
+        self.num_freq, self.frame_length_ms, self.frame_shift_ms = self._stft_parameters()
+
+    def _stft_parameters(self):
+        """compute frame length and hop length in ms"""
+        frame_length_ms = self.win_length * 1. / self.sample_rate
+        frame_shift_ms = self.hop_length * 1. / self.sample_rate
+        num_freq = 1 + self.n_fft // 2
+        return num_freq, frame_length_ms, frame_shift_ms
+
+    def __repr__(self):
+        """object repr"""
+        cls_name_str = self.__class__.__name__
+        members = vars(self)
+        dict_str = "\n".join(["  {}: {},".format(k, v) for k, v in members.items()])
+        repr_str = "{}(\n{})\n".format(cls_name_str, dict_str)
+        return repr_str
+
+    def save_wav(self, path, wav):
+        """save audio with scipy.io.wavfile in 16bit integers"""
+        wav_norm = wav * (32767 / max(0.01, np.max(np.abs(wav))))
+        scipy.io.wavfile.write(path, self.sample_rate, wav_norm.as_type(np.int16))
+
+    def load_wav(self, path, sr=None):
+        """load wav -> trim_silence -> rescale"""
+
+        x, sr = librosa.load(path, sr=None)
+        assert self.sample_rate == sr, "audio sample rate: {}Hz != processor sample rate: {}Hz".format(sr, self.sample_rate)
+        if self.do_trim_silence:
+            try:
+                x = self.trim_silence(x)
+            except ValueError:
+                print(" [!] File cannot be trimmed for silence - {}".format(path))
+        if self.sound_norm:
+            x = x / x.max() * 0.9 # why 0.9 ?
+        return x
+
+    def trim_silence(self, wav):
+        """Trim soilent parts with a threshold and 0.01s margin"""
+        margin = int(self.sample_rate * 0.01)
+        wav = wav[margin: -margin]
+        trimed_wav = librosa.effects.trim(wav, top_db=60, frame_length=self.win_length, hop_length=self.hop_length)[0]
+        return trimed_wav
+
+    def apply_preemphasis(self, x):
+        if self.preemphasis == 0.:
+            raise RuntimeError(" !! Preemphasis coefficient should be positive. ")
+        return scipy.signal.lfilter([1., -self.preemphasis], [1.], x)
+
+    def apply_inv_preemphasis(self, x):
+        if self.preemphasis == 0.:
+            raise RuntimeError(" !! Preemphasis coefficient should be positive. ")
+        return scipy.signal.lfilter([1.], [1., -self.preemphasis], x)
+
+    def _amplitude_to_db(self, x):
+        amplitude_min = np.exp(self.min_level_db / 20 * np.log(10))
+        return 20 * np.log10(np.maximum(amplitude_min, x))
+
+    @staticmethod
+    def _db_to_amplitude(x):
+        return np.power(10., 0.05 * x)
+
+    def _linear_to_mel(self, spectrogram):
+        _mel_basis = self._build_mel_basis()
+        return np.dot(_mel_basis, spectrogram)
+
+    def _mel_to_linear(self, mel_spectrogram):
+        inv_mel_basis = np.linalg.pinv(self._build_mel_basis())
+        return np.maximum(1e-10, np.dot(inv_mel_basis, mel_spectrogram))
+
+    def _build_mel_basis(self):
+        """return mel basis for mel scale"""
+        if self.mel_fmax is not None:
+            assert self.mel_fmax <= self.sample_rate // 2
+        return librosa.filters.mel(
+            self.sample_rate, 
+            self.n_fft, 
+            n_mels=self.num_mels,
+            fmin=self.mel_fmin,
+            fmax=self.mel_fmax)
+
+    def _normalize(self, S):
+        """put values in [0, self.max_norm] or [-self.max_norm, self,max_norm]"""
+        if self.signal_norm:
+            S_norm = (S - self.min_level_db) / (-self.min_level_db)
+            if self.symmetric_norm:
+                S_norm = ((2 * self.max_norm) * S_norm) - self.max_norm
+                if self.clip_norm:
+                    S_norm = np.clip(S_norm, -self.max_norm, self.max_norm)
+                return S_norm
+            else:
+                S_norm = self.max_norm * S_norm
+                if self.clip_norm:
+                    S_norm = np.clip(S_norm, 0, self.max_norm)
+                return S_norm
+        else:
+            return S
+
+    def _denormalize(self, S):
+        """denormalize values"""
+        S_denorm = S
+        if self.signal_norm:
+            if self.symmetric_norm:
+                if self.clip_norm:
+                    S_denorm = np.clip(S_denorm, -self.max_norm, self.max_norm)
+                S_denorm = (S_denorm + self.max_norm) * (-self.min_level_db) / (2 * self.max_norm) + self.min_level_db
+                return S_denorm
+            else:
+                if self.clip_norm:
+                    S_denorm = np.clip(S_denorm, 0, self.max_norm)
+                S_denorm = S_denorm * (-self.min_level_db)/ self.max_norm + self.min_level_db
+                return S_denorm
+        else:
+            return S
+
+    def _stft(self, y):
+        return librosa.stft(
+            y=y, 
+            n_fft=self.n_fft,
+            win_length=self.win_length,
+            hop_length=self.hop_length)
+
+    def _istft(self, S):
+        return librosa.istft(S, hop_length=self.hop_length, win_length=self.win_length)
+
+    def spectrogram(self, y):
+        """compute linear spectrogram(amplitude)
+        preemphasis -> stft -> mag -> amplitude_to_db -> minus_ref_level_db -> normalize
+        """
+        if self.preemphasis:
+            D = self._stft(self.apply_preemphasis(y))
+        else:
+            D = self._stft(y)
+        S = self._amplitude_to_db(np.abs(D)) - self.ref_level_db
+        return self._normalize(S)
+
+    def melspectrogram(self, y):
+        """compute linear spectrogram(amplitude)
+        preemphasis -> stft -> mag -> mel_scale -> amplitude_to_db -> minus_ref_level_db -> normalize
+        """
+        if self.preemphasis:
+            D = self._stft(self.apply_preemphasis(y))
+        else:
+            D = self._stft(y)
+        S = self._amplitude_to_db(self._linear_to_mel(np.abs(D))) - self.ref_level_db
+        return self._normalize(S)
+
+    def inv_spectrogram(self, spectrogram):
+        """convert spectrogram back to waveform using griffin_lim in librosa"""
+        S = self._denormalize(spectrogram)
+        S = self._db_to_amplitude(S + self.ref_level_db)
+        if self.preemphasis:
+            return self.apply_inv_preemphasis(self._griffin_lim(S ** self.power))
+        return self._griffin_lim(S ** self.power)
+
+    def inv_melspectrogram(self, mel_spectrogram):
+        S = self._denormalize(mel_spectrogram)
+        S = self._db_to_amplitude(S + self.ref_level_db)
+        S = self._linear_to_mel(np.abs(S))
+        if self.preemphasis:
+            return self.apply_inv_preemphasis(self._griffin_lim(S ** self.power))
+        return self._griffin_lim(S ** self.power)
+
+    def out_linear_to_mel(self, linear_spec):
+        """convert output linear spec to mel spec"""
+        S = self._denormalize(linear_spec)
+        S = self._db_to_amplitude(S + self.ref_level_db)
+        S = self._linear_to_mel(np.abs(S))
+        S = self._amplitude_to_db(S) - self.ref_level_db
+        mel = self._normalize(S)
+        return mel
+        
+    def _griffin_lim(self, S):
+        angles = np.exp(2j * np.pi * np.random.rand(*S.shape))
+        S_complex = np.abs(S).astype(np.complex)
+        y = self._istft(S_complex * angles)
+        for _ in range(self.griffin_lim_iters):
+            angles = np.exp(1j * np.angle(self._stft(y)))
+            y = self._istft(S_complex * angles)
+        return y
+
+    @staticmethod
+    def mulaw_encode(wav, qc):
+        mu = 2 ** qc - 1
+        # wav_abs = np.minimum(np.abs(wav), 1.0)
+        signal = np.sign(wav) * np.log(1 + mu * np.abs(wav)) / np.log(1. + mu)
+        # Quantize signal to the specified number of levels.
+        signal = (signal + 1) / 2 * mu + 0.5
+        return np.floor(signal,)
+
+    @staticmethod
+    def mulaw_decode(wav, qc):
+        """Recovers waveform from quantized values."""
+        mu = 2 ** qc - 1
+        x = np.sign(wav) / mu * ((1 + mu) ** np.abs(wav) - 1)
+        return x
+
+    @staticmethod
+    def encode_16bits(x):
+        return np.clip(x * 2**15, -2**15, 2**15 - 1).astype(np.int16)
+
+    @staticmethod
+    def quantize(x, bits):
+        return (x + 1.) * (2**bits - 1) / 2
+
+    @staticmethod
+    def dequantize(x, bits):
+        return 2 * x / (2**bits - 1) - 1
diff --git a/parakeet/data/batch.py b/parakeet/data/batch.py
index 9303b46..8777472 100644
--- a/parakeet/data/batch.py
+++ b/parakeet/data/batch.py
@@ -88,7 +88,7 @@ def batch_spec(minibatch, pad_value=0., dtype=np.float32):
         mono_channel = False
     
     lengths = [example.shape[-1] for example in minibatch] # assume (channel, F, n_frame) or (F, n_frame)
-    max_len = np.max(lengths)
+    max_len = np.max(lengths)  
     
     batch = []
     for example in minibatch:
diff --git a/parakeet/data/datacargo.py b/parakeet/data/datacargo.py
index 1d7d8d5..e087a4f 100644
--- a/parakeet/data/datacargo.py
+++ b/parakeet/data/datacargo.py
@@ -2,7 +2,8 @@ from .sampler import SequentialSampler, RandomSampler, BatchSampler
 
 class DataCargo(object):
     def __init__(self, dataset, batch_size=1, sampler=None, 
-                 shuffle=False, batch_sampler=None, drop_last=False):
+                 shuffle=False, batch_sampler=None, collate_fn=None,
+                 drop_last=False):
         self.dataset = dataset
         
         if batch_sampler is not None:
@@ -21,13 +22,20 @@ class DataCargo(object):
                 sampler = RandomSampler(dataset)
             else:
                 sampler = SequentialSampler(dataset)
-            # auto_collation without custom batch_sampler
             batch_sampler = BatchSampler(sampler, batch_size, drop_last)
+        else:
+            batch_sampler = BatchSampler(sampler, batch_size, drop_last)
+
+        self.batch_sampler = batch_sampler
+
+        if collate_fn is None:
+            collate_fn = dataset._batch_examples
+        self.collate_fn = collate_fn
 
         self.batch_size = batch_size
         self.drop_last = drop_last
         self.sampler = sampler
-        self.batch_sampler = batch_sampler
+        
     
     def __iter__(self):
         return DataIterator(self)
@@ -57,6 +65,7 @@ class DataIterator(object):
         
         self._index_sampler = loader._index_sampler
         self._sampler_iter = iter(self._index_sampler)
+        self.collate_fn = loader.collate_fn
     
     def __iter__(self):
         return self
@@ -64,7 +73,7 @@ class DataIterator(object):
     def __next__(self):
         index = self._next_index()  # may raise StopIteration, TODO(chenfeiyu): use dynamic batch size
         minibatch = [self._dataset[i] for i in index] # we can abstract it, too to use dynamic batch size
-        minibatch = self._dataset._batch_examples(minibatch) # list[Example] -> Batch
+        minibatch = self.collate_fn(minibatch)
         return minibatch
     
     def _next_index(self):
diff --git a/parakeet/models/dataloader/__init__.py b/parakeet/models/dataloader/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/parakeet/models/dataloader/jlspeech.py b/parakeet/models/dataloader/jlspeech.py
new file mode 100644
index 0000000..ef55b0f
--- /dev/null
+++ b/parakeet/models/dataloader/jlspeech.py
@@ -0,0 +1,148 @@
+from pathlib import Path
+import numpy as np
+import pandas as pd
+import librosa
+
+from paddle import fluid
+from parakeet import g2p
+from parakeet import audio
+from parakeet.data.sampler import *
+from parakeet.data.datacargo import DataCargo
+from parakeet.data.dataset import Dataset
+from parakeet.data.batch import TextIDBatcher, SpecBatcher
+
+class LJSpeechLoader:
+    def __init__(self, config, nranks, rank, is_vocoder=False, shuffle=True):
+        place = fluid.CUDAPlace(rank) if config.use_gpu else fluid.CPUPlace()
+
+        LJSPEECH_ROOT = Path(config.data_path)
+        dataset = LJSpeech(LJSPEECH_ROOT, config)
+        sampler = DistributedSampler(len(dataset), nranks, rank, shuffle=shuffle)
+
+        assert config.batch_size % nranks == 0
+        each_bs = config.batch_size // nranks
+        if is_vocoder:
+            dataloader = DataCargo(dataset, sampler=sampler, batch_size=each_bs, shuffle=shuffle, collate_fn=batch_examples_vocoder, drop_last=True)
+        else:
+            dataloader = DataCargo(dataset, sampler=sampler, batch_size=each_bs, shuffle=shuffle, collate_fn=batch_examples, drop_last=True)
+        
+        self.reader = fluid.io.DataLoader.from_generator(
+            capacity=32,
+            iterable=True,
+            use_double_buffer=True,
+            return_list=True)
+        self.reader.set_batch_generator(dataloader, place)
+
+
+class LJSpeech(Dataset):
+    def __init__(self, root, config):
+        super(LJSpeech, self).__init__()
+        assert isinstance(root, (str, Path)), "root should be a string or Path object"
+        self.root = root if isinstance(root, Path) else Path(root)
+        self.metadata = self._prepare_metadata()
+        self.config = config
+        self._ljspeech_processor = audio.AudioProcessor(
+            sample_rate=config.audio.sr, 
+            num_mels=config.audio.num_mels, 
+            min_level_db=config.audio.min_level_db, 
+            ref_level_db=config.audio.ref_level_db, 
+            n_fft=config.audio.n_fft, 
+            win_length= config.audio.win_length, 
+            hop_length= config.audio.hop_length,
+            power=config.audio.power,
+            preemphasis=config.audio.preemphasis,
+            signal_norm=True,
+            symmetric_norm=False,
+            max_norm=1.,
+            mel_fmin=0,
+            mel_fmax=None,
+            clip_norm=True,
+            griffin_lim_iters=60,
+            do_trim_silence=False,
+            sound_norm=False)
+        
+    def _prepare_metadata(self):
+        csv_path = self.root.joinpath("metadata.csv")
+        metadata = pd.read_csv(csv_path, sep="|", header=None, quoting=3,
+                               names=["fname", "raw_text", "normalized_text"])
+        return metadata
+            
+    def _get_example(self, metadatum):
+        """All the code for generating an Example from a metadatum. If you want a 
+        different preprocessing pipeline, you can override this method. 
+        This method may require several processor, each of which has a lot of options.
+        In this case, you'd better pass a composed transform and pass it to the init
+        method.
+        """
+        
+        fname, raw_text, normalized_text = metadatum
+        wav_path = self.root.joinpath("wavs", fname + ".wav")
+        
+        # load -> trim -> preemphasis -> stft -> magnitude -> mel_scale -> logscale -> normalize
+        wav = self._ljspeech_processor.load_wav(str(wav_path))
+        mag = self._ljspeech_processor.spectrogram(wav).astype(np.float32)
+        mel = self._ljspeech_processor.melspectrogram(wav).astype(np.float32)
+        phonemes = np.array(g2p.en.text_to_sequence(normalized_text), dtype=np.int64)
+        return (mag, mel, phonemes) # maybe we need to implement it as a map in the future
+
+    def __getitem__(self, index):
+        metadatum = self.metadata.iloc[index]
+        example = self._get_example(metadatum)
+        return example
+    
+    def __iter__(self):
+        for i in range(len(self)):
+            yield self[i]
+    
+    def __len__(self):
+        return len(self.metadata)
+
+
+def batch_examples(batch):
+    texts = []
+    mels = []
+    mel_inputs = []
+    text_lens = []
+    pos_texts = []
+    pos_mels = []
+    for data in batch:
+        _, mel, text = data
+        mel_inputs.append(np.concatenate([np.zeros([mel.shape[0], 1], np.float32), mel[:,:-1]], axis=-1))
+        text_lens.append(len(text))
+        pos_texts.append(np.arange(1, len(text) + 1))
+        pos_mels.append(np.arange(1, mel.shape[1] + 1))
+        mels.append(mel)
+        texts.append(text)
+    
+    # Sort by text_len in descending order
+    texts = [i for i,_ in sorted(zip(texts, text_lens), key=lambda x: x[1], reverse=True)]
+    mels = [i for i,_ in sorted(zip(mels, text_lens), key=lambda x: x[1], reverse=True)]
+    mel_inputs = [i for i,_ in sorted(zip(mel_inputs, text_lens), key=lambda x: x[1], reverse=True)]
+    pos_texts = [i for i,_ in sorted(zip(pos_texts, text_lens), key=lambda x: x[1], reverse=True)]
+    pos_mels = [i for i,_ in sorted(zip(pos_mels, text_lens), key=lambda x: x[1], reverse=True)]
+    text_lens = sorted(text_lens, reverse=True)
+
+    # Pad sequence with largest len of the batch
+    texts = TextIDBatcher(pad_id=0)(texts)   #(B, T)
+    pos_texts = TextIDBatcher(pad_id=0)(pos_texts) #(B,T)
+    pos_mels = TextIDBatcher(pad_id=0)(pos_mels) #(B,T)
+    mels = np.transpose(SpecBatcher(pad_value=0.)(mels), axes=(0,2,1)) #(B,T,num_mels)
+    mel_inputs = np.transpose(SpecBatcher(pad_value=0.)(mel_inputs), axes=(0,2,1))#(B,T,num_mels)
+    return (texts, mels, mel_inputs, pos_texts, pos_mels, np.array(text_lens))
+
+def batch_examples_vocoder(batch):
+    mels=[]
+    mags=[]
+    for data in batch:
+        mag, mel, _ = data
+        mels.append(mel)
+        mags.append(mag)
+
+    mels = np.transpose(SpecBatcher(pad_value=0.)(mels), axes=(0,2,1))
+    mags = np.transpose(SpecBatcher(pad_value=0.)(mags), axes=(0,2,1))
+
+    return (mels, mags)
+
+
+
+        
diff --git a/parakeet/models/fastspeech/__init__.py b/parakeet/models/fastspeech/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/parakeet/models/fastspeech/config/fastapeech.yaml b/parakeet/models/fastspeech/config/fastapeech.yaml
new file mode 100644
index 0000000..3e62846
--- /dev/null
+++ b/parakeet/models/fastspeech/config/fastapeech.yaml
@@ -0,0 +1,41 @@
+audio:
+  num_mels: 80
+  n_fft: 2048
+  sr: 22050
+  preemphasis: 0.97
+  hop_length: 275
+  win_length: 1102
+  power: 1.2
+  min_level_db: -100
+  ref_level_db: 20
+  outputs_per_step: 1
+
+encoder_n_layer: 6
+encoder_head: 2
+encoder_conv1d_filter_size: 1536
+max_sep_len: 2048
+encoder_output_size: 384
+word_vec_dim: 384
+decoder_n_layer: 6
+decoder_head: 2
+decoder_conv1d_filter_size: 1536
+decoder_output_size: 384
+d_model: 384
+duration_predictor_output_size: 256
+duration_predictor_filter_size: 3
+fft_conv1d_filter: 3
+fft_conv1d_padding: 1
+
+
+batch_size: 32
+epochs: 10000
+lr: 0.001
+save_step: 500
+image_step: 2000
+use_gpu: False
+use_data_parallel: False
+
+data_path: ../../../dataset/LJSpeech-1.1
+transtts_path: ./checkpoint
+transformer_step: 70000
+log_dir: ./log
\ No newline at end of file
diff --git a/parakeet/models/fastspeech/config/fastspeech.yaml b/parakeet/models/fastspeech/config/fastspeech.yaml
new file mode 100644
index 0000000..947457b
--- /dev/null
+++ b/parakeet/models/fastspeech/config/fastspeech.yaml
@@ -0,0 +1,43 @@
+audio:
+  num_mels: 80
+  n_fft: 2048
+  sr: 22050
+  preemphasis: 0.97
+  hop_length: 275
+  win_length: 1102
+  power: 1.2
+  min_level_db: -100
+  ref_level_db: 20
+  outputs_per_step: 1
+
+encoder_n_layer: 6
+encoder_head: 2
+encoder_conv1d_filter_size: 1536
+max_sep_len: 2048
+encoder_output_size: 384
+embedding_size: 384
+decoder_n_layer: 6
+decoder_head: 2
+decoder_conv1d_filter_size: 1536
+decoder_output_size: 384
+hidden_size: 384
+duration_predictor_output_size: 256
+duration_predictor_filter_size: 3
+fft_conv1d_filter: 3
+fft_conv1d_padding: 1
+dropout: 0.1
+transformer_head: 4
+
+warm_up_step: 4000
+grad_clip_thresh: 0.1
+batch_size: 32
+epochs: 10000
+lr: 0.001
+save_step: 500
+use_gpu: True
+use_data_parallel: False
+
+data_path: ../../../dataset/LJSpeech-1.1
+transtts_path: ../transformerTTS/checkpoint
+transformer_step: 20
+log_dir: ./log
\ No newline at end of file
diff --git a/parakeet/models/fastspeech/modules.py b/parakeet/models/fastspeech/modules.py
new file mode 100644
index 0000000..621b5c1
--- /dev/null
+++ b/parakeet/models/fastspeech/modules.py
@@ -0,0 +1,150 @@
+import numpy as np
+import math
+import utils
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+import paddle.fluid as fluid
+from parakeet.modules.layers import Conv1D
+from parakeet.modules.multihead_attention import MultiheadAttention
+from parakeet.modules.feed_forward import PositionwiseFeedForward
+
+
+
+class FFTBlock(dg.Layer):
+    def __init__(self, d_model, d_inner, n_head, d_k, d_v, filter_size, padding, dropout=0.2):
+        super(FFTBlock, self).__init__()
+        self.slf_attn = MultiheadAttention(d_model, d_k, d_v, num_head=n_head, dropout=dropout)
+        self.pos_ffn = PositionwiseFeedForward(d_model, d_inner, filter_size =filter_size, padding =padding, dropout=dropout)
+
+    def forward(self, enc_input, non_pad_mask=None, slf_attn_mask=None):
+        """
+        Feed Forward Transformer block in FastSpeech.
+        
+        Args:
+            enc_input (Variable): Shape(B, T, C), dtype: float32. The embedding characters input. 
+                T means the timesteps of input.
+            non_pad_mask (Variable): Shape(B, T, 1), dtype: int64. The mask of sequence.
+            slf_attn_mask (Variable): Shape(B, len_q, len_k), dtype: int64. The mask of self attention. 
+                len_q means the sequence length of query, len_k means the sequence length of key.
+
+        Returns:
+            output (Variable), Shape(B, T, C), the output after self-attention & ffn.
+            slf_attn (Variable), Shape(B * n_head, T, T), the self attention.
+        """
+        output, slf_attn = self.slf_attn(enc_input, enc_input, enc_input, mask=slf_attn_mask)
+        output *= non_pad_mask
+
+        output = self.pos_ffn(output)
+        output *= non_pad_mask
+
+        return output, slf_attn
+
+
+class LengthRegulator(dg.Layer):
+    def __init__(self, input_size, out_channels, filter_size, dropout=0.1):
+        super(LengthRegulator, self).__init__()
+        self.duration_predictor = DurationPredictor(input_size=input_size, 
+                                                    out_channels=out_channels, 
+                                                    filter_size=filter_size, 
+                                                    dropout=dropout)
+
+    def LR(self, x, duration_predictor_output, alpha=1.0):
+        output = []
+        batch_size = x.shape[0]
+        for i in range(batch_size):
+            output.append(self.expand(x[i:i+1], duration_predictor_output[i:i+1], alpha))
+        output = self.pad(output)
+        return output
+    
+    def pad(self, input_ele):
+        max_len = max([input_ele[i].shape[0] for i in range(len(input_ele))])
+        out_list = []
+        for i in range(len(input_ele)):
+            pad_len = max_len - input_ele[i].shape[0]
+            one_batch_padded = layers.pad(
+                input_ele[i], [0, pad_len, 0, 0], pad_value=0.0)
+            out_list.append(one_batch_padded)
+        out_padded = layers.stack(out_list)
+        return out_padded
+    
+    def expand(self, batch, predicted, alpha):
+        out = []
+        time_steps = batch.shape[1]
+        fertilities = predicted.numpy()
+        batch = layers.squeeze(batch,[0]) 
+        
+        
+        for i in range(time_steps):
+            if fertilities[0,i]==0:
+                continue
+            out.append(layers.expand(batch[i: i + 1, :], [int(fertilities[0,i]), 1]))
+        out = layers.concat(out, axis=0)
+        return out
+    
+
+    def forward(self, x, alpha=1.0, target=None):
+        """
+        Length Regulator block in FastSpeech.
+        
+        Args:
+            x (Variable): Shape(B, T, C), dtype: float32. The encoder output.
+            alpha (Constant): dtype: float32. The hyperparameter to determine the length of 
+                the expanded sequence mel, thereby controlling the voice speed.
+            target (Variable): (Variable, optional): Shape(B, T_text),
+                dtype: int64. The duration of phoneme compute from pretrained transformerTTS.
+
+        Returns:
+            output (Variable), Shape(B, T, C), the output after exppand.
+            duration_predictor_output (Variable), Shape(B, T, C), the output of duration predictor.
+        """
+        duration_predictor_output = self.duration_predictor(x)
+        if fluid.framework._dygraph_tracer()._train_mode:
+            output = self.LR(x, target)
+            return output, duration_predictor_output
+        else:
+            duration_predictor_output = layers.round(duration_predictor_output)
+            output = self.LR(x, duration_predictor_output, alpha)
+            mel_pos = dg.to_variable([i+1 for i in range(output.shape[1])])
+            return output, mel_pos
+
+class DurationPredictor(dg.Layer):
+    def __init__(self, input_size, out_channels, filter_size, dropout=0.1):
+        super(DurationPredictor, self).__init__()
+        self.input_size = input_size
+        self.out_channels = out_channels
+        self.filter_size = filter_size
+        self.dropout = dropout
+
+        self.conv1 = Conv1D(in_channels = self.input_size, 
+                        out_channels = self.out_channels, 
+                        filter_size = self.filter_size,
+                        padding=1,
+                        data_format='NTC')
+        self.conv2 = Conv1D(in_channels = self.out_channels, 
+                        out_channels = self.out_channels, 
+                        filter_size = self.filter_size,
+                        padding=1,
+                        data_format='NTC')
+        self.layer_norm1 = dg.LayerNorm(self.out_channels)
+        self.layer_norm2 = dg.LayerNorm(self.out_channels)
+
+        self.linear =dg.Linear(self.out_channels, 1)
+
+    def forward(self, encoder_output):
+        """
+        Duration Predictor block in FastSpeech.
+        
+        Args:
+            encoder_output (Variable): Shape(B, T, C), dtype: float32. The encoder output.
+        Returns:
+            out (Variable), Shape(B, T, C), the output of duration predictor.
+        """
+        # encoder_output.shape(N, T, C)
+        out = layers.dropout(layers.relu(self.layer_norm1(self.conv1(encoder_output))), self.dropout)
+        out = layers.dropout(layers.relu(self.layer_norm2(self.conv2(out))), self.dropout)
+        out = layers.relu(self.linear(out))
+        out = layers.squeeze(out, axes=[-1])
+            
+        return out
+
+        
diff --git a/parakeet/models/fastspeech/network.py b/parakeet/models/fastspeech/network.py
new file mode 100644
index 0000000..2f8dc9a
--- /dev/null
+++ b/parakeet/models/fastspeech/network.py
@@ -0,0 +1,214 @@
+from utils import *
+from modules import *
+import paddle.fluid.dygraph as dg
+import paddle.fluid as fluid
+from parakeet.g2p.text.symbols import symbols
+from parakeet.modules.utils import *
+from parakeet.modules.post_convnet import PostConvNet
+
+class Encoder(dg.Layer):
+    def __init__(self,
+                 n_src_vocab,
+                 len_max_seq,
+                 d_word_vec,
+                 n_layers,
+                 n_head,
+                 d_k,
+                 d_v,
+                 d_model,
+                 d_inner,
+                 fft_conv1d_kernel,
+                 fft_conv1d_padding,
+                 dropout=0.1):
+        super(Encoder, self).__init__()
+        n_position = len_max_seq + 1
+
+        self.src_word_emb = dg.Embedding(size=[n_src_vocab, d_word_vec], padding_idx=0)
+        self.pos_inp = get_sinusoid_encoding_table(n_position, d_word_vec, padding_idx=0)
+        self.position_enc = dg.Embedding(size=[n_position, d_word_vec],
+                                 padding_idx=0,
+                                 param_attr=fluid.ParamAttr(
+                                     initializer=fluid.initializer.NumpyArrayInitializer(self.pos_inp),
+                                     trainable=False))
+        self.layer_stack = [FFTBlock(d_model, d_inner, n_head, d_k, d_v, fft_conv1d_kernel, fft_conv1d_padding, dropout=dropout) for _ in range(n_layers)]
+        for i, layer in enumerate(self.layer_stack):
+            self.add_sublayer('fft_{}'.format(i), layer)
+
+    def forward(self, character, text_pos):
+        """
+        Encoder layer of FastSpeech.
+        
+        Args:
+            character (Variable): Shape(B, T_text), dtype: float32. The input text
+                characters. T_text means the timesteps of input characters.
+            text_pos (Variable): Shape(B, T_text), dtype: int64. The input text
+                position. T_text means the timesteps of input characters.
+
+        Returns:
+            enc_output (Variable), Shape(B, text_T, C), the encoder output.
+            non_pad_mask (Variable), Shape(B, T_text, 1), the mask with non pad.
+            enc_slf_attn_list (list<Variable>), Len(n_layers), Shape(B * n_head, text_T, text_T), the encoder self attention list.
+        """
+        enc_slf_attn_list = []
+        # -- prepare masks
+        # shape character (N, T)
+        slf_attn_mask = get_attn_key_pad_mask(seq_k=character, seq_q=character)
+        non_pad_mask = get_non_pad_mask(character)
+
+        # -- Forward
+        enc_output = self.src_word_emb(character) + self.position_enc(text_pos) #(N, T, C)
+
+        for enc_layer in self.layer_stack:
+            enc_output, enc_slf_attn = enc_layer(
+                enc_output,
+                non_pad_mask=non_pad_mask,
+                slf_attn_mask=slf_attn_mask)
+            enc_slf_attn_list += [enc_slf_attn]
+        
+        return enc_output, non_pad_mask, enc_slf_attn_list
+
+class Decoder(dg.Layer):
+    def __init__(self,
+                 len_max_seq,
+                 d_word_vec,
+                 n_layers,
+                 n_head,
+                 d_k,
+                 d_v,
+                 d_model,
+                 d_inner,
+                 fft_conv1d_kernel,
+                 fft_conv1d_padding,
+                 dropout=0.1):
+        super(Decoder, self).__init__()
+
+        n_position = len_max_seq + 1
+        self.pos_inp = get_sinusoid_encoding_table(n_position, d_word_vec, padding_idx=0)
+        self.position_enc = dg.Embedding(size=[n_position, d_word_vec],
+                                 padding_idx=0,
+                                 param_attr=fluid.ParamAttr(
+                                     initializer=fluid.initializer.NumpyArrayInitializer(self.pos_inp),
+                                     trainable=False))
+        self.layer_stack = [FFTBlock(d_model, d_inner, n_head, d_k, d_v, fft_conv1d_kernel, fft_conv1d_padding, dropout=dropout) for _ in range(n_layers)] 
+        for i, layer in enumerate(self.layer_stack):
+            self.add_sublayer('fft_{}'.format(i), layer)
+    
+    def forward(self, enc_seq, enc_pos):
+        """
+        Decoder layer of FastSpeech.
+        
+        Args:
+            enc_seq (Variable), Shape(B, text_T, C), dtype: float32. 
+                The output of length regulator.
+            enc_pos (Variable, optional): Shape(B, T_mel),
+                dtype: int64. The spectrum position. T_mel means the timesteps of input spectrum.
+        Returns:
+            dec_output (Variable), Shape(B, mel_T, C), the decoder output.
+            dec_slf_attn_list (Variable), Shape(B, mel_T, mel_T), the decoder self attention list.
+        """
+        dec_slf_attn_list = []
+
+        # -- Prepare masks
+        slf_attn_mask = get_attn_key_pad_mask(seq_k=enc_pos, seq_q=enc_pos)
+        non_pad_mask = get_non_pad_mask(enc_pos)
+
+        # -- Forward
+        dec_output = enc_seq + self.position_enc(enc_pos)
+
+        for dec_layer in self.layer_stack:
+            dec_output, dec_slf_attn = dec_layer(
+                dec_output,
+                non_pad_mask=non_pad_mask,
+                slf_attn_mask=slf_attn_mask)
+            dec_slf_attn_list += [dec_slf_attn]
+
+        return dec_output, dec_slf_attn_list
+
+class FastSpeech(dg.Layer):
+    def __init__(self, cfg):
+        " FastSpeech"
+        super(FastSpeech, self).__init__()
+
+        self.encoder = Encoder(n_src_vocab=len(symbols)+1,
+                               len_max_seq=cfg.max_sep_len,
+                               d_word_vec=cfg.embedding_size,
+                               n_layers=cfg.encoder_n_layer,
+                               n_head=cfg.encoder_head,
+                               d_k=64,
+                               d_v=64,
+                               d_model=cfg.hidden_size,
+                               d_inner=cfg.encoder_conv1d_filter_size,
+                               fft_conv1d_kernel=cfg.fft_conv1d_filter, 
+                               fft_conv1d_padding=cfg.fft_conv1d_padding,
+                               dropout=0.1)
+        self.length_regulator = LengthRegulator(input_size=cfg.hidden_size, 
+                                                out_channels=cfg.duration_predictor_output_size, 
+                                                filter_size=cfg.duration_predictor_filter_size, 
+                                                dropout=cfg.dropout)
+        self.decoder = Decoder(len_max_seq=cfg.max_sep_len,
+                                d_word_vec=cfg.embedding_size,
+                                n_layers=cfg.decoder_n_layer,
+                                n_head=cfg.decoder_head,
+                                d_k=64,
+                                d_v=64,
+                                d_model=cfg.hidden_size,
+                                d_inner=cfg.decoder_conv1d_filter_size,
+                                fft_conv1d_kernel=cfg.fft_conv1d_filter, 
+                                fft_conv1d_padding=cfg.fft_conv1d_padding,
+                                dropout=0.1)
+        self.mel_linear = dg.Linear(cfg.decoder_output_size, cfg.audio.num_mels)
+        self.postnet = PostConvNet(n_mels=80,
+                 num_hidden=512,
+                 filter_size=5,
+                 padding=int(5 / 2),
+                 num_conv=5,
+                 outputs_per_step=1,
+                 use_cudnn=True,
+                 dropout=0.1)
+
+    def forward(self, character, text_pos, mel_pos=None, length_target=None, alpha=1.0):
+        """
+        FastSpeech model.
+        
+        Args:
+            character (Variable): Shape(B, T_text), dtype: float32. The input text
+                characters. T_text means the timesteps of input characters.
+            text_pos (Variable): Shape(B, T_text), dtype: int64. The input text
+                position. T_text means the timesteps of input characters.
+            mel_pos (Variable, optional): Shape(B, T_mel),
+                dtype: int64. The spectrum position. T_mel means the timesteps of input spectrum.
+            length_target (Variable, optional): Shape(B, T_text),
+                dtype: int64. The duration of phoneme compute from pretrained transformerTTS.
+            alpha (Constant): 
+                dtype: float32. The hyperparameter to determine the length of the expanded sequence 
+                mel, thereby controlling the voice speed.
+
+        Returns:
+            mel_output (Variable), Shape(B, mel_T, C), the mel output before postnet.
+            mel_output_postnet (Variable), Shape(B, mel_T, C), the mel output after postnet.
+            duration_predictor_output (Variable), Shape(B, text_T), the duration of phoneme compute 
+            with duration predictor.
+            enc_slf_attn_list (Variable), Shape(B, text_T, text_T), the encoder self attention list.
+            dec_slf_attn_list (Variable), Shape(B, mel_T, mel_T), the decoder self attention list.
+        """
+
+        encoder_output, non_pad_mask, enc_slf_attn_list = self.encoder(character, text_pos)
+        if fluid.framework._dygraph_tracer()._train_mode:
+            
+            length_regulator_output, duration_predictor_output = self.length_regulator(encoder_output,
+                                                                                       target=length_target,
+                                                                                       alpha=alpha)
+            decoder_output, dec_slf_attn_list = self.decoder(length_regulator_output, mel_pos)
+
+            mel_output = self.mel_linear(decoder_output)
+            mel_output_postnet = self.postnet(mel_output) + mel_output
+
+            return mel_output, mel_output_postnet, duration_predictor_output, enc_slf_attn_list, dec_slf_attn_list
+        else:
+            length_regulator_output, decoder_pos = self.length_regulator(encoder_output, alpha=alpha)
+            decoder_output = self.decoder(length_regulator_output, decoder_pos)
+
+            mel_output = self.mel_linear(decoder_output)
+            mel_output_postnet = self.postnet(mel_output) + mel_output
+
+            return mel_output, mel_output_postnet
\ No newline at end of file
diff --git a/parakeet/models/fastspeech/parse.py b/parakeet/models/fastspeech/parse.py
new file mode 100644
index 0000000..4132674
--- /dev/null
+++ b/parakeet/models/fastspeech/parse.py
@@ -0,0 +1,93 @@
+import jsonargparse
+
+def add_config_options_to_parser(parser):
+    parser.add_argument('--audio.num_mels', type=int, default=80,
+        help="the number of mel bands when calculating mel spectrograms.")
+    parser.add_argument('--audio.n_fft', type=int, default=2048,
+        help="the number of fft components.")
+    parser.add_argument('--audio.sr', type=int, default=22050,
+        help="the sampling rate of audio data file.")
+    parser.add_argument('--audio.preemphasis', type=float, default=0.97,
+        help="the preemphasis coefficient.")
+    parser.add_argument('--audio.hop_length', type=int, default=128,
+        help="the number of samples to advance between frames.")
+    parser.add_argument('--audio.win_length', type=int, default=1024,
+        help="the length (width) of the window function.")
+    parser.add_argument('--audio.power', type=float, default=1.4,
+        help="the power to raise before griffin-lim.")
+    parser.add_argument('--audio.min_level_db', type=int, default=-100,
+        help="the minimum level db.")
+    parser.add_argument('--audio.ref_level_db', type=int, default=20,
+        help="the reference level db.")
+    parser.add_argument('--audio.outputs_per_step', type=int, default=1,
+        help="the outputs per step.")
+    
+    parser.add_argument('--embedding_size', type=int, default=256,
+        help="the dim size of embedding.")
+    parser.add_argument('--encoder_n_layer', type=int, default=6,
+        help="the number of FFT Block in encoder.")
+    parser.add_argument('--encoder_head', type=int, default=2,
+        help="the attention head number in encoder.")
+    parser.add_argument('--encoder_conv1d_filter_size', type=int, default=1024,
+        help="the filter size of conv1d in encoder.")
+    parser.add_argument('--max_sep_len', type=int, default=2048,
+        help="the max length of sequence.")
+    parser.add_argument('--encoder_output_size', type=int, default=256,
+        help="the output channel size of encoder.")
+    parser.add_argument('--decoder_n_layer', type=int, default=6,
+        help="the number of FFT Block in decoder.")
+    parser.add_argument('--decoder_head', type=int, default=2,
+        help="the attention head number in decoder.")
+    parser.add_argument('--decoder_conv1d_filter_size', type=int, default=1024,
+        help="the filter size of conv1d in decoder.")
+    parser.add_argument('--decoder_output_size', type=int, default=256,
+        help="the output channel size of decoder.")
+    parser.add_argument('--hidden_size', type=int, default=256,
+        help="the hidden size in model.")
+    parser.add_argument('--duration_predictor_output_size', type=int, default=256,
+        help="the output size of duration predictior.")
+    parser.add_argument('--duration_predictor_filter_size', type=int, default=3,
+        help="the filter size of conv1d in duration prediction.")
+    parser.add_argument('--fft_conv1d_filter', type=int, default=3,
+        help="the filter size of conv1d in fft.")
+    parser.add_argument('--fft_conv1d_padding', type=int, default=1,
+        help="the padding size of conv1d in fft.")
+    parser.add_argument('--dropout', type=float, default=0.1,
+        help="the dropout in network.")
+    parser.add_argument('--transformer_head', type=int, default=4,
+        help="the attention head num of transformerTTS.")
+
+    parser.add_argument('--warm_up_step', type=int, default=4000,
+        help="the warm up step of learning rate.")
+    parser.add_argument('--grad_clip_thresh', type=float, default=1.0,
+        help="the threshold of grad clip.")
+    parser.add_argument('--batch_size', type=int, default=32,
+        help="batch size for training.")
+    parser.add_argument('--epochs', type=int, default=10000,
+        help="the number of epoch for training.")
+    parser.add_argument('--lr', type=float, default=0.001,
+        help="the learning rate for training.")
+    parser.add_argument('--save_step', type=int, default=500,
+        help="checkpointing interval during training.")
+    parser.add_argument('--use_gpu', type=bool, default=True,
+        help="use gpu or not during training.")
+    parser.add_argument('--use_data_parallel', type=bool, default=False,
+        help="use data parallel or not during training.")
+
+    parser.add_argument('--data_path', type=str, default='./dataset/LJSpeech-1.1',
+        help="the path of dataset.")
+    parser.add_argument('--checkpoint_path', type=str, default=None,
+        help="the path to load checkpoint or pretrain model.")
+    parser.add_argument('--save_path', type=str, default='./checkpoint',
+        help="the path to save checkpoint.")
+    parser.add_argument('--log_dir', type=str, default='./log',
+        help="the directory to save tensorboard log.")
+    parser.add_argument('--sample_path', type=str, default='./sample',
+        help="the directory to save audio sample in synthesis.")
+    parser.add_argument('--transtts_path', type=str, default='./log',
+        help="the directory to load pretrain transformerTTS model.")
+    parser.add_argument('--transformer_step', type=int, default=70000,
+        help="the step to load transformerTTS model.")
+    
+
+    parser.add_argument('-c', '--config', action=jsonargparse.ActionConfigFile)
diff --git a/parakeet/models/fastspeech/train.py b/parakeet/models/fastspeech/train.py
new file mode 100644
index 0000000..243631c
--- /dev/null
+++ b/parakeet/models/fastspeech/train.py
@@ -0,0 +1,139 @@
+import numpy as np
+import argparse
+import os
+import time
+import math
+import jsonargparse
+from pathlib import Path
+from tqdm import tqdm
+from tensorboardX import SummaryWriter
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+import paddle.fluid as fluid
+from parse import add_config_options_to_parser
+from pprint import pprint
+from network import FastSpeech
+from utils import get_alignment
+from parakeet.models.dataloader.jlspeech import LJSpeechLoader
+from parakeet.models.transformerTTS.network import TransformerTTS
+
+class MyDataParallel(dg.parallel.DataParallel):
+    """
+    A data parallel proxy for model.
+    """
+
+    def __init__(self, layers, strategy):
+        super(MyDataParallel, self).__init__(layers, strategy)
+
+    def __getattr__(self, key):
+        if key in self.__dict__:
+            return object.__getattribute__(self, key)
+        elif key is "_layers":
+            return object.__getattribute__(self, "_sub_layers")["_layers"]
+        else:
+            return getattr(
+                object.__getattribute__(self, "_sub_layers")["_layers"], key)
+
+def main(cfg):
+
+    local_rank = dg.parallel.Env().local_rank if cfg.use_data_parallel else 0
+    nranks = dg.parallel.Env().nranks if cfg.use_data_parallel else 1
+
+    if local_rank == 0:
+        # Print the whole config setting.
+        pprint(jsonargparse.namespace_to_dict(cfg))
+
+    global_step = 0
+    place = (fluid.CUDAPlace(dg.parallel.Env().dev_id)
+             if cfg.use_data_parallel else fluid.CUDAPlace(0)
+             if cfg.use_gpu else fluid.CPUPlace())
+
+    if not os.path.exists(cfg.log_dir):
+            os.mkdir(cfg.log_dir)
+    path = os.path.join(cfg.log_dir,'fastspeech')
+
+    writer = SummaryWriter(path) if local_rank == 0 else None
+
+    with dg.guard(place):
+        transformerTTS = TransformerTTS(cfg)
+        model_path = os.path.join(cfg.transtts_path, "transformer")
+        model_dict, _ = fluid.dygraph.load_dygraph(os.path.join(model_path, str(cfg.transformer_step)))
+        #for param in transformerTTS.state_dict():
+        #   print(param)
+        
+        transformerTTS.set_dict(model_dict)
+        transformerTTS.eval()
+
+        model = FastSpeech(cfg)
+        model.train()
+        optimizer = fluid.optimizer.AdamOptimizer(learning_rate=dg.NoamDecay(1/(cfg.warm_up_step *( cfg.lr ** 2)), cfg.warm_up_step),
+                                                  parameter_list=model.parameters())
+        reader = LJSpeechLoader(cfg, nranks, local_rank).reader()
+        
+        if cfg.checkpoint_path is not None:
+            model_dict, opti_dict = fluid.dygraph.load_dygraph(cfg.checkpoint_path)
+            model.set_dict(model_dict)
+            optimizer.set_dict(opti_dict)
+            print("load checkpoint!!!")
+
+        if cfg.use_data_parallel:
+            strategy = dg.parallel.prepare_context()
+            model = MyDataParallel(model, strategy)
+
+        for epoch in range(cfg.epochs):
+            pbar = tqdm(reader)
+
+            for i, data in enumerate(pbar):
+                pbar.set_description('Processing at epoch %d'%epoch)
+                character, mel, mel_input, pos_text, pos_mel, text_length = data
+
+                _, _, attn_probs, _, _, _ = transformerTTS(character, mel_input, pos_text, pos_mel)
+                alignment = dg.to_variable(get_alignment(attn_probs, cfg.transformer_head)).astype(np.float32)
+
+                global_step += 1
+                    
+                #Forward
+                result= model(character, 
+                              pos_text, 
+                              mel_pos=pos_mel,  
+                              length_target=alignment)
+                mel_output, mel_output_postnet, duration_predictor_output, _, _ = result
+                mel_loss = layers.mse_loss(mel_output, mel)
+                mel_postnet_loss = layers.mse_loss(mel_output_postnet, mel)
+                duration_loss = layers.mean(layers.abs(layers.elementwise_sub(duration_predictor_output, alignment)))
+                total_loss = mel_loss + mel_postnet_loss + duration_loss
+
+                if local_rank==0:
+                    print('epoch:{}, step:{}, mel_loss:{}, mel_postnet_loss:{}, duration_loss:{}'.format(epoch, global_step, mel_loss.numpy(), mel_postnet_loss.numpy(), duration_loss.numpy()))
+
+                    writer.add_scalar('mel_loss', mel_loss.numpy(), global_step)
+                    writer.add_scalar('post_mel_loss', mel_postnet_loss.numpy(), global_step)
+                    writer.add_scalar('duration_loss', duration_loss.numpy(), global_step)
+                    writer.add_scalar('learning_rate', optimizer._learning_rate.step().numpy(), global_step)
+
+
+                if cfg.use_data_parallel:
+                    total_loss = model.scale_loss(total_loss)
+                    total_loss.backward()
+                    model.apply_collective_grads()
+                else:
+                    total_loss.backward()
+                optimizer.minimize(total_loss, grad_clip = fluid.dygraph_grad_clip.GradClipByGlobalNorm(cfg.grad_clip_thresh))
+                model.clear_gradients()
+
+                 # save checkpoint
+                if local_rank==0 and global_step % cfg.save_step == 0:
+                    if not os.path.exists(cfg.save_path):
+                        os.mkdir(cfg.save_path)
+                    save_path = os.path.join(cfg.save_path,'fastspeech/%d' % global_step)
+                    dg.save_dygraph(model.state_dict(), save_path)
+                    dg.save_dygraph(optimizer.state_dict(), save_path)
+        if local_rank==0:
+            writer.close()
+
+
+if __name__ =='__main__':
+    parser = jsonargparse.ArgumentParser(description="Train Fastspeech model", formatter_class='default_argparse')
+    add_config_options_to_parser(parser)
+    cfg = parser.parse_args('-c config/fastspeech.yaml'.split())
+    main(cfg)
\ No newline at end of file
diff --git a/parakeet/models/fastspeech/utils.py b/parakeet/models/fastspeech/utils.py
new file mode 100644
index 0000000..7517a13
--- /dev/null
+++ b/parakeet/models/fastspeech/utils.py
@@ -0,0 +1,32 @@
+import numpy as np
+
+def get_alignment(attn_probs, n_head):
+    max_F = 0
+    assert attn_probs[0].shape[0] % n_head == 0
+    batch_size = int(attn_probs[0].shape[0] // n_head)
+    for i in range(len(attn_probs)):
+        multi_attn = attn_probs[i].numpy()
+        for j in range(n_head):
+            attn = multi_attn[j*batch_size:(j+1)*batch_size]
+            F = score_F(attn)
+            if max_F < F:
+                max_F = F
+                max_attn = attn
+    alignment = compute_duration(max_attn)
+    return alignment
+    
+def score_F(attn):
+    max = np.max(attn, axis=-1)
+    mean = np.mean(max)
+    return mean
+
+def compute_duration(attn):
+    alignment = np.zeros([attn.shape[0],attn.shape[2]])
+    for i in range(attn.shape[0]):
+        for j in range(attn.shape[1]):
+            max_index = attn[i,j].tolist().index(attn[i,j].max())
+            alignment[i,max_index] += 1
+
+    return alignment
+
+
diff --git a/parakeet/models/transformerTTS/config/synthesis.yaml b/parakeet/models/transformerTTS/config/synthesis.yaml
new file mode 100644
index 0000000..c3c3f8c
--- /dev/null
+++ b/parakeet/models/transformerTTS/config/synthesis.yaml
@@ -0,0 +1,20 @@
+audio:
+  num_mels: 80
+  n_fft: 2048
+  sr: 22050
+  preemphasis: 0.97
+  hop_length: 275
+  win_length: 1102
+  power: 1.2
+  min_level_db: -100
+  ref_level_db: 20
+  outputs_per_step: 1
+
+max_len: 50
+transformer_step: 1
+postnet_step: 1
+use_gpu: True
+
+checkpoint_path: ./checkpoint
+log_dir: ./log
+sample_path: ./sample
\ No newline at end of file
diff --git a/parakeet/models/transformerTTS/config/train_postnet.yaml b/parakeet/models/transformerTTS/config/train_postnet.yaml
new file mode 100644
index 0000000..74e1b5a
--- /dev/null
+++ b/parakeet/models/transformerTTS/config/train_postnet.yaml
@@ -0,0 +1,27 @@
+audio:
+  num_mels: 80
+  n_fft: 2048
+  sr: 22050
+  preemphasis: 0.97
+  hop_length: 275
+  win_length: 1102
+  power: 1.2
+  min_level_db: -100
+  ref_level_db: 20
+  outputs_per_step: 1
+
+hidden_size: 256
+embedding_size: 512
+
+warm_up_step: 4000
+grad_clip_thresh: 1.0
+batch_size: 32
+epochs: 10000
+lr: 0.001
+save_step: 500
+use_gpu: True
+use_data_parallel: True
+
+data_path: ../../../dataset/LJSpeech-1.1
+save_path: ./checkpoint
+log_dir: ./log
\ No newline at end of file
diff --git a/parakeet/models/transformerTTS/config/train_transformer.yaml b/parakeet/models/transformerTTS/config/train_transformer.yaml
new file mode 100644
index 0000000..0fbde62
--- /dev/null
+++ b/parakeet/models/transformerTTS/config/train_transformer.yaml
@@ -0,0 +1,33 @@
+audio:
+  num_mels: 80
+  n_fft: 2048
+  sr: 22050
+  preemphasis: 0.97
+  hop_length: 275
+  win_length: 1102
+  power: 1.2
+  min_level_db: -100
+  ref_level_db: 20
+  outputs_per_step: 1
+
+
+hidden_size: 256
+embedding_size: 512
+
+
+warm_up_step: 4000
+grad_clip_thresh: 1.0
+batch_size: 32
+epochs: 10000
+lr: 0.001
+save_step: 1000
+image_step: 2000
+use_gpu: True
+use_data_parallel: False
+
+data_path: ../../../dataset/LJSpeech-1.1
+save_path: ./checkpoint
+log_dir: ./log
+#checkpoint_path: ./checkpoint/transformer/1
+
+   
\ No newline at end of file
diff --git a/parakeet/models/transformerTTS/layers.py b/parakeet/models/transformerTTS/layers.py
new file mode 100644
index 0000000..7a8e97e
--- /dev/null
+++ b/parakeet/models/transformerTTS/layers.py
@@ -0,0 +1,166 @@
+import math
+import numpy as np
+
+import paddle
+from paddle import fluid
+import paddle.fluid.dygraph as dg
+
+
+class Conv1D(dg.Layer):
+    """
+    A convolution 1D block implemented with Conv2D. Form simplicity and 
+    ensuring the output has the same length as the input, it does not allow 
+    stride > 1.
+    """
+
+    def __init__(self,
+                 in_channels,
+                 num_filters,
+                 filter_size=3,
+                 padding=0,
+                 dilation=1,
+                 stride=1,
+                 groups=None,
+                 param_attr=None,
+                 bias_attr=None,
+                 use_cudnn=True,
+                 act=None,
+                 data_format='NCT',
+                 dtype="float32"):
+        super(Conv1D, self).__init__(dtype=dtype)
+
+        self.padding = padding
+        self.in_channels = in_channels
+        self.num_filters = num_filters
+        self.filter_size = filter_size
+        self.stride = stride
+        self.dilation = dilation
+        self.padding = padding
+        self.act = act
+        self.data_format = data_format
+
+        self.conv = dg.Conv2D(
+            in_channels=in_channels,
+            num_filters=num_filters,
+            filter_size=(1, filter_size),
+            stride=(1, stride),
+            dilation=(1, dilation),
+            padding=(0, padding),
+            groups=groups,
+            param_attr=param_attr,
+            bias_attr=bias_attr,
+            use_cudnn=use_cudnn,
+            act=act,
+            dtype=dtype)
+
+    def forward(self, x):
+        """
+        Args:
+            x (Variable): Shape(B, C_in, 1, T), the input, where C_in means
+                input channels.
+        Returns:
+            x (Variable): Shape(B, C_out, 1, T), the outputs, where C_out means
+                output channels (num_filters).
+        """
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        x = fluid.layers.unsqueeze(x, [2])
+        x = self.conv(x)
+        x = fluid.layers.squeeze(x, [2])
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        return x
+
+class Pool1D(dg.Layer):
+    """
+    A Pool 1D block implemented with Pool2D.
+    """
+    def __init__(self,
+                 pool_size=-1, 
+                 pool_type='max', 
+                 pool_stride=1, 
+                 pool_padding=0, 
+                 global_pooling=False, 
+                 use_cudnn=True, 
+                 ceil_mode=False, 
+                 exclusive=True,
+                 data_format='NCT', 
+                 dtype='float32'):
+        super(Pool1D, self).__init__(dtype=dtype)
+        self.pool_size = pool_size
+        self.pool_type = pool_type
+        self.pool_stride = pool_stride
+        self.pool_padding = pool_padding
+        self.global_pooling = global_pooling
+        self.use_cudnn = use_cudnn
+        self.ceil_mode = ceil_mode
+        self.exclusive = exclusive
+        self.data_format = data_format
+        self.dtype = dtype
+
+
+        self.pool2d = dg.Pool2D([1,pool_size], pool_type = pool_type,
+                                pool_stride = [1,pool_stride], pool_padding = [0, pool_padding],
+                                global_pooling = global_pooling, use_cudnn = use_cudnn,
+                                ceil_mode = ceil_mode, exclusive = exclusive, dtype = dtype)
+
+    
+    def forward(self, x):
+        """
+        Args:
+            x (Variable): Shape(B, C_in, 1, T), the input, where C_in means
+                input channels.
+        Returns:
+            x (Variable): Shape(B, C_out, 1, T), the outputs, where C_out means
+                output channels (num_filters).
+        """
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        x = fluid.layers.unsqueeze(x, [2])
+        x = self.pool2d(x)
+        x = fluid.layers.squeeze(x, [2])
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        return x
+
+class DynamicGRU(dg.Layer):
+    def __init__(self,
+                 size,
+                 param_attr=None,
+                 bias_attr=None,
+                 is_reverse=False,
+                 gate_activation='sigmoid',
+                 candidate_activation='tanh',
+                 h_0=None,
+                 origin_mode=False,
+                 init_size=None):
+        super(DynamicGRU, self).__init__()
+        self.gru_unit = dg.GRUUnit(
+            size * 3,
+            param_attr=param_attr,
+            bias_attr=bias_attr,
+            activation=candidate_activation,
+            gate_activation=gate_activation,
+            origin_mode=origin_mode)
+        self.size = size
+        self.h_0 = h_0
+        self.is_reverse = is_reverse
+
+    def forward(self, inputs):
+        hidden = self.h_0
+        res = []
+        for i in range(inputs.shape[1]):
+            if self.is_reverse:
+                i = inputs.shape[1] - 1 - i
+            input_ = inputs[:, i:i + 1, :]
+            input_ = fluid.layers.reshape(
+                input_, [-1, input_.shape[2]], inplace=False)
+            hidden, reset, gate = self.gru_unit(input_, hidden)
+            hidden_ = fluid.layers.reshape(
+                hidden, [-1, 1, hidden.shape[1]], inplace=False)
+            res.append(hidden_)
+        if self.is_reverse:
+            res = res[::-1]
+        res = fluid.layers.concat(res, axis=1)
+        return res
+
diff --git a/parakeet/models/transformerTTS/module.py b/parakeet/models/transformerTTS/module.py
new file mode 100644
index 0000000..ecacb1b
--- /dev/null
+++ b/parakeet/models/transformerTTS/module.py
@@ -0,0 +1,242 @@
+import math
+from parakeet.g2p.text.symbols import symbols
+import paddle.fluid.dygraph as dg
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+from parakeet.modules.layers import Conv, Pool1D
+from parakeet.modules.dynamicGRU import DynamicGRU
+import numpy as np
+
+
+
+class EncoderPrenet(dg.Layer):
+    def __init__(self, embedding_size, num_hidden, use_cudnn=True):
+        super(EncoderPrenet, self).__init__()
+        self.embedding_size = embedding_size
+        self.num_hidden = num_hidden
+        self.use_cudnn = use_cudnn
+        self.embedding = dg.Embedding( size = [len(symbols), embedding_size], 
+                                        param_attr = fluid.ParamAttr(name='weight'),
+                                        padding_idx = None)
+        self.conv_list = []
+        self.conv_list.append(Conv(in_channels = embedding_size, 
+                            out_channels = num_hidden, 
+                            filter_size = 5,
+                            padding = int(np.floor(5/2)),
+                            use_cudnn = use_cudnn,
+                            data_format = "NCT"))
+        for _ in range(2):
+            self.conv_list.append(Conv(in_channels = num_hidden, 
+                                out_channels = num_hidden, 
+                                filter_size = 5,
+                                padding = int(np.floor(5/2)),
+                                use_cudnn = use_cudnn,
+                                data_format = "NCT"))
+
+        for i, layer in enumerate(self.conv_list):
+            self.add_sublayer("conv_list_{}".format(i), layer)
+
+        self.batch_norm_list = [dg.BatchNorm(num_hidden, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW') for _ in range(3)]
+
+        for i, layer in enumerate(self.batch_norm_list):
+            self.add_sublayer("batch_norm_list_{}".format(i), layer)
+
+        self.projection = dg.Linear(num_hidden, num_hidden)
+
+    def forward(self, x):
+        x = self.embedding(x) #(batch_size, seq_len, embending_size)
+        x = layers.transpose(x,[0,2,1])
+        for batch_norm, conv in zip(self.batch_norm_list, self.conv_list):
+            x = layers.dropout(layers.relu(batch_norm(conv(x))), 0.2)
+        x = layers.transpose(x,[0,2,1]) #(N,T,C)
+        x = self.projection(x)
+        return x
+
+class CBHG(dg.Layer):
+    def __init__(self, hidden_size, batch_size, K=16, projection_size = 256, num_gru_layers=2, 
+                 max_pool_kernel_size=2, is_post=False):
+        super(CBHG, self).__init__()
+        """
+        :param hidden_size: dimension of hidden unit
+        :param K: # of convolution banks
+        :param projection_size: dimension of projection unit
+        :param num_gru_layers: # of layers of GRUcell
+        :param max_pool_kernel_size: max pooling kernel size
+        :param is_post: whether post processing or not
+        """
+        self.hidden_size = hidden_size
+        self.projection_size = projection_size
+        self.conv_list = []
+        self.conv_list.append(Conv(in_channels = projection_size,
+                            out_channels = hidden_size,
+                            filter_size = 1,
+                            padding = int(np.floor(1/2)),
+                            data_format = "NCT"))
+        for i in range(2,K+1):
+            self.conv_list.append(Conv(in_channels = hidden_size,
+                            out_channels = hidden_size,
+                            filter_size = i,
+                            padding = int(np.floor(i/2)),
+                            data_format = "NCT"))
+
+        for i, layer in enumerate(self.conv_list):
+            self.add_sublayer("conv_list_{}".format(i), layer)
+
+        self.batchnorm_list = []
+        for i in range(K):
+            self.batchnorm_list.append(dg.BatchNorm(hidden_size, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW'))
+
+        for i, layer in enumerate(self.batchnorm_list):
+            self.add_sublayer("batchnorm_list_{}".format(i), layer)
+
+        conv_outdim = hidden_size * K
+
+        self.conv_projection_1 = Conv(in_channels = conv_outdim,
+                            out_channels = hidden_size,
+                            filter_size = 3,
+                            padding = int(np.floor(3/2)),
+                            data_format = "NCT")
+
+        self.conv_projection_2 = Conv(in_channels = hidden_size,
+                            out_channels = projection_size,
+                            filter_size = 3,
+                            padding = int(np.floor(3/2)),
+                            data_format = "NCT")
+
+        self.batchnorm_proj_1 = dg.BatchNorm(hidden_size, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW')
+        self.batchnorm_proj_2 = dg.BatchNorm(projection_size, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW')
+        self.max_pool = Pool1D(pool_size = max_pool_kernel_size, 
+                    pool_type='max', 
+                    pool_stride=1, 
+                    pool_padding=1,
+                    data_format = "NCT")
+        self.highway = Highwaynet(self.projection_size)
+
+        h_0 = np.zeros((batch_size, hidden_size // 2), dtype="float32")
+        h_0 = dg.to_variable(h_0)
+        self.fc_forward1 = dg.Linear(hidden_size, hidden_size // 2 * 3)
+        self.fc_reverse1 = dg.Linear(hidden_size, hidden_size // 2 * 3)
+        self.gru_forward1 = DynamicGRU(size = self.hidden_size // 2,
+                              param_attr = fluid.ParamAttr(name='weight'), 
+                              bias_attr = fluid.ParamAttr(name='bias'),
+                              is_reverse = False,
+                              origin_mode = True,
+                              h_0 = h_0)
+        self.gru_reverse1 = DynamicGRU(size = self.hidden_size // 2,
+                              param_attr = fluid.ParamAttr(name='weight'), 
+                              bias_attr = fluid.ParamAttr(name='bias'),
+                              is_reverse=True,
+                              origin_mode=True,
+                              h_0 = h_0)
+
+        self.fc_forward2 = dg.Linear(hidden_size, hidden_size // 2 * 3)
+        self.fc_reverse2 = dg.Linear(hidden_size, hidden_size // 2 * 3)
+        self.gru_forward2 = DynamicGRU(size = self.hidden_size // 2,
+                              param_attr = fluid.ParamAttr(name='weight'), 
+                              bias_attr = fluid.ParamAttr(name='bias'),
+                              is_reverse = False,
+                              origin_mode = True,
+                              h_0 = h_0)
+        self.gru_reverse2 = DynamicGRU(size = self.hidden_size // 2,
+                              param_attr = fluid.ParamAttr(name='weight'), 
+                              bias_attr = fluid.ParamAttr(name='bias'),
+                              is_reverse=True,
+                              origin_mode=True,
+                              h_0 = h_0)
+
+    def _conv_fit_dim(self, x, filter_size=3):
+        if filter_size % 2 == 0:
+            return x[:,:,:-1]
+        else:
+            return x 
+
+    def forward(self, input_):
+        # input_.shape = [N, C, T]
+
+        conv_list = []
+        conv_input = input_
+        
+        for i, (conv, batchnorm) in enumerate(zip(self.conv_list, self.batchnorm_list)):
+            conv_input = self._conv_fit_dim(conv(conv_input), i+1)
+            conv_input = layers.relu(batchnorm(conv_input))
+            conv_list.append(conv_input)
+        
+        conv_cat = layers.concat(conv_list, axis=1)
+        conv_pool = self.max_pool(conv_cat)[:,:,:-1]
+        
+        
+        conv_proj = layers.relu(self.batchnorm_proj_1(self._conv_fit_dim(self.conv_projection_1(conv_pool))))
+        conv_proj = self.batchnorm_proj_2(self._conv_fit_dim(self.conv_projection_2(conv_proj))) + input_
+        
+        # conv_proj.shape = [N, C, T]
+        highway = layers.transpose(conv_proj, [0,2,1])
+        highway = self.highway(highway)
+
+        # highway.shape = [N, T, C]
+        fc_forward = self.fc_forward1(highway)
+        fc_reverse = self.fc_reverse1(highway)
+        out_forward = self.gru_forward1(fc_forward)
+        out_reverse = self.gru_reverse1(fc_reverse)
+        out = layers.concat([out_forward, out_reverse], axis=-1)
+        fc_forward = self.fc_forward2(out)
+        fc_reverse = self.fc_reverse2(out)
+        out_forward = self.gru_forward2(fc_forward)
+        out_reverse = self.gru_reverse2(fc_reverse)
+        out = layers.concat([out_forward, out_reverse], axis=-1)
+        out = layers.transpose(out, [0,2,1])
+        return out
+
+class Highwaynet(dg.Layer):
+    def __init__(self, num_units, num_layers=4):
+        super(Highwaynet, self).__init__()
+        self.num_units = num_units
+        self.num_layers = num_layers
+
+        self.gates = []
+        self.linears = []
+
+        for i in range(num_layers):
+            self.linears.append(dg.Linear(num_units, num_units))
+            self.gates.append(dg.Linear(num_units, num_units))
+        
+        for i, (linear, gate) in enumerate(zip(self.linears,self.gates)):
+            self.add_sublayer("linears_{}".format(i), linear)
+            self.add_sublayer("gates_{}".format(i), gate)
+
+    def forward(self, input_):
+        out = input_
+
+        for linear, gate in zip(self.linears, self.gates):
+            h = fluid.layers.relu(linear(out))
+            t_ = fluid.layers.sigmoid(gate(out))
+
+            c = 1 - t_
+            out  = h * t_ + out  * c
+            
+        return out
+
+
+
+
+                
+        
diff --git a/parakeet/models/transformerTTS/network.py b/parakeet/models/transformerTTS/network.py
new file mode 100644
index 0000000..5f353f8
--- /dev/null
+++ b/parakeet/models/transformerTTS/network.py
@@ -0,0 +1,206 @@
+from parakeet.models.transformerTTS.module import *
+import paddle.fluid.dygraph as dg
+import paddle.fluid as fluid
+from parakeet.modules.layers import Conv1D
+from parakeet.modules.utils import *
+from parakeet.modules.multihead_attention import MultiheadAttention
+from parakeet.modules.feed_forward import PositionwiseFeedForward
+from parakeet.modules.prenet import PreNet
+from parakeet.modules.post_convnet import PostConvNet
+
+
+class Encoder(dg.Layer):
+    def __init__(self, embedding_size, num_hidden, config):
+        super(Encoder, self).__init__()
+        self.num_hidden = num_hidden
+        param = fluid.ParamAttr(name='alpha',  
+                                initializer=fluid.initializer.Constant(value=1.0))
+        self.alpha = self.create_parameter(shape=(1, ), attr=param, dtype='float32')
+        self.pos_inp = get_sinusoid_encoding_table(1024, self.num_hidden, padding_idx=0)
+        self.pos_emb = dg.Embedding(size=[1024, num_hidden],
+                                 padding_idx=0,
+                                 param_attr=fluid.ParamAttr(
+                                     initializer=fluid.initializer.NumpyArrayInitializer(self.pos_inp),
+                                     trainable=False))
+        self.encoder_prenet = EncoderPrenet(embedding_size = embedding_size, 
+                                            num_hidden = num_hidden, 
+                                            use_cudnn=config.use_gpu)
+        self.layers = [MultiheadAttention(num_hidden, num_hidden//4, num_hidden//4) for _ in range(3)]
+        for i, layer in enumerate(self.layers):
+            self.add_sublayer("self_attn_{}".format(i), layer)
+        self.ffns = [PositionwiseFeedForward(num_hidden, num_hidden*4, filter_size=1, use_cudnn = config.use_gpu) for _ in range(3)]
+        for i, layer in enumerate(self.ffns):
+            self.add_sublayer("ffns_{}".format(i), layer)
+
+    def forward(self, x, positional):
+        if fluid.framework._dygraph_tracer()._train_mode:
+            query_mask = get_non_pad_mask(positional)
+            mask = get_attn_key_pad_mask(positional, x)
+        else:
+            query_mask, mask = None, None
+        
+        
+        # Encoder pre_network
+        x = self.encoder_prenet(x) #(N,T,C)
+        
+        
+        # Get positional encoding
+        positional = self.pos_emb(positional) 
+        x = positional * self.alpha + x #(N, T, C)
+       
+
+        # Positional dropout
+        x = layers.dropout(x, 0.1)
+        
+        # Self attention encoder
+        attentions = list()
+        for layer, ffn in zip(self.layers, self.ffns):
+            x, attention = layer(x, x, x, mask = mask, query_mask = query_mask)
+            x = ffn(x)
+            attentions.append(attention)
+
+        return x, query_mask, attentions
+
+class Decoder(dg.Layer):
+    def __init__(self, num_hidden, config):
+        super(Decoder, self).__init__()
+        self.num_hidden = num_hidden
+        param = fluid.ParamAttr(name='alpha')
+        self.alpha = self.create_parameter(shape=(1,), attr=param, dtype='float32',
+                        default_initializer = fluid.initializer.ConstantInitializer(value=1.0))
+        self.pos_inp = get_sinusoid_encoding_table(1024, self.num_hidden, padding_idx=0)
+        self.pos_emb = dg.Embedding(size=[1024, num_hidden],
+                                 padding_idx=0,
+                                 param_attr=fluid.ParamAttr(
+                                     name='weight',
+                                     initializer=fluid.initializer.NumpyArrayInitializer(self.pos_inp),
+                                     trainable=False))
+        self.decoder_prenet = PreNet(input_size = config.audio.num_mels, 
+                                            hidden_size = num_hidden * 2, 
+                                            output_size = num_hidden, 
+                                            dropout_rate=0.2)
+        self.linear = dg.Linear(num_hidden, num_hidden)
+
+        self.selfattn_layers = [MultiheadAttention(num_hidden, num_hidden//4, num_hidden//4) for _ in range(3)]
+        for i, layer in enumerate(self.selfattn_layers):
+            self.add_sublayer("self_attn_{}".format(i), layer)
+        self.attn_layers = [MultiheadAttention(num_hidden, num_hidden//4, num_hidden//4) for _ in range(3)]
+        for i, layer in enumerate(self.attn_layers):
+            self.add_sublayer("attn_{}".format(i), layer)
+        self.ffns = [PositionwiseFeedForward(num_hidden, num_hidden*4, filter_size=1) for _ in range(3)]
+        for i, layer in enumerate(self.ffns):
+            self.add_sublayer("ffns_{}".format(i), layer)
+        self.mel_linear = dg.Linear(num_hidden, config.audio.num_mels * config.audio.outputs_per_step)
+        self.stop_linear = dg.Linear(num_hidden, 1)
+
+        self.postconvnet = PostConvNet(config.audio.num_mels, config.hidden_size, 
+                                       filter_size = 5, padding = 4, num_conv=5, 
+                                       outputs_per_step=config.audio.outputs_per_step, 
+                                       use_cudnn = config.use_gpu)
+
+    def forward(self, key, value, query, c_mask, positional):
+
+        # get decoder mask with triangular matrix
+        
+        if fluid.framework._dygraph_tracer()._train_mode:
+            m_mask = get_non_pad_mask(positional)
+            mask = get_attn_key_pad_mask((positional==0).astype(np.float32), query)
+            triu_tensor = dg.to_variable(get_triu_tensor(query.numpy(), query.numpy())).astype(np.float32)
+            mask = mask + triu_tensor
+            mask = fluid.layers.cast(mask == 0, np.float32)
+            
+            # (batch_size, decoder_len, encoder_len)
+            zero_mask = get_attn_key_pad_mask(layers.squeeze(c_mask,[-1]), query)
+        else:
+            mask = get_triu_tensor(query.numpy(), query.numpy()).astype(np.float32)
+            mask = fluid.layers.cast(dg.to_variable(mask == 0), np.float32)
+            m_mask, zero_mask = None, None
+        
+        # Decoder pre-network
+        query = self.decoder_prenet(query)
+
+        # Centered position
+        query = self.linear(query)
+
+        # Get position embedding
+        positional = self.pos_emb(positional)
+        query = positional * self.alpha + query
+
+        #positional dropout
+        query = fluid.layers.dropout(query, 0.1)
+
+        # Attention decoder-decoder, encoder-decoder
+        selfattn_list = list()
+        attn_list = list()
+
+        for selfattn, attn, ffn in zip(self.selfattn_layers, self.attn_layers, self.ffns):
+            query, attn_dec = selfattn(query, query, query, mask = mask, query_mask = m_mask)
+            query, attn_dot = attn(key, value, query, mask = zero_mask, query_mask = m_mask)
+            query = ffn(query)
+            selfattn_list.append(attn_dec)
+            attn_list.append(attn_dot)
+        
+        # Mel linear projection
+        mel_out = self.mel_linear(query)
+        # Post Mel Network
+        out = self.postconvnet(mel_out)
+        out = mel_out + out
+        
+        # Stop tokens
+        stop_tokens = self.stop_linear(query)
+        stop_tokens = layers.squeeze(stop_tokens, [-1])
+        stop_tokens = layers.sigmoid(stop_tokens)
+
+        return mel_out, out, attn_list, stop_tokens, selfattn_list
+
+class TransformerTTS(dg.Layer):
+    def __init__(self, config):
+        super(TransformerTTS, self).__init__()
+        self.encoder = Encoder(config.embedding_size, config.hidden_size, config)
+        self.decoder = Decoder(config.hidden_size, config)
+        self.config = config
+
+    def forward(self, characters, mel_input, pos_text, pos_mel):
+        # key (batch_size, seq_len, channel)
+        # c_mask (batch_size, seq_len)
+        # attns_enc (channel / 2, seq_len, seq_len)
+        
+        key, c_mask, attns_enc = self.encoder(characters, pos_text)
+        
+        # mel_output/postnet_output (batch_size, mel_len, n_mel)
+        # attn_probs (128, mel_len, seq_len)
+        # stop_preds (batch_size, mel_len, 1)
+        # attns_dec (128, mel_len, mel_len)
+        mel_output, postnet_output, attn_probs, stop_preds, attns_dec = self.decoder(key, key, mel_input, c_mask, pos_mel)
+
+        return mel_output, postnet_output, attn_probs, stop_preds, attns_enc, attns_dec
+
+class ModelPostNet(dg.Layer):
+    """
+    CBHG Network (mel -> linear)
+    """
+    def __init__(self, config):
+        super(ModelPostNet, self).__init__()
+        self.pre_proj = Conv1D(in_channels = config.audio.num_mels, 
+                             out_channels = config.hidden_size,
+                             filter_size=1,
+                             data_format = "NCT")
+        self.cbhg = CBHG(config.hidden_size, config.batch_size)
+        self.post_proj = Conv1D(in_channels = config.hidden_size, 
+                             out_channels = (config.audio.n_fft // 2) + 1,
+                             filter_size=1,
+                             data_format = "NCT")
+
+    def forward(self, mel):
+        mel = layers.transpose(mel, [0,2,1])
+        mel = self.pre_proj(mel)
+        mel = self.cbhg(mel)
+        mag_pred = self.post_proj(mel)
+        mag_pred = layers.transpose(mag_pred, [0,2,1])
+        return mag_pred
+
+    
+
+
+            
+            
diff --git a/parakeet/models/transformerTTS/parse.py b/parakeet/models/transformerTTS/parse.py
new file mode 100644
index 0000000..584ea63
--- /dev/null
+++ b/parakeet/models/transformerTTS/parse.py
@@ -0,0 +1,67 @@
+import jsonargparse
+
+def add_config_options_to_parser(parser):
+    parser.add_argument('--audio.num_mels', type=int, default=80,
+        help="the number of mel bands when calculating mel spectrograms.")
+    parser.add_argument('--audio.n_fft', type=int, default=2048,
+        help="the number of fft components.")
+    parser.add_argument('--audio.sr', type=int, default=22050,
+        help="the sampling rate of audio data file.")
+    parser.add_argument('--audio.preemphasis', type=float, default=0.97,
+        help="the preemphasis coefficient.")
+    parser.add_argument('--audio.hop_length', type=int, default=128,
+        help="the number of samples to advance between frames.")
+    parser.add_argument('--audio.win_length', type=int, default=1024,
+        help="the length (width) of the window function.")
+    parser.add_argument('--audio.power', type=float, default=1.4,
+        help="the power to raise before griffin-lim.")
+    parser.add_argument('--audio.min_level_db', type=int, default=-100,
+        help="the minimum level db.")
+    parser.add_argument('--audio.ref_level_db', type=int, default=20,
+        help="the reference level db.")
+    parser.add_argument('--audio.outputs_per_step', type=int, default=1,
+        help="the outputs per step.")
+    
+    parser.add_argument('--hidden_size', type=int, default=256,
+        help="the hidden size in network.")
+    parser.add_argument('--embedding_size', type=int, default=512,
+        help="the embedding vector size.")
+
+    parser.add_argument('--warm_up_step', type=int, default=4000,
+        help="the warm up step of learning rate.")
+    parser.add_argument('--grad_clip_thresh', type=float, default=1.0,
+        help="the threshold of grad clip.")
+    parser.add_argument('--batch_size', type=int, default=32,
+        help="batch size for training.")
+    parser.add_argument('--epochs', type=int, default=10000,
+        help="the number of epoch for training.")
+    parser.add_argument('--lr', type=float, default=0.001,
+        help="the learning rate for training.")
+    parser.add_argument('--save_step', type=int, default=500,
+        help="checkpointing interval during training.")
+    parser.add_argument('--image_step', type=int, default=2000,
+        help="attention image interval during training.")
+    parser.add_argument('--max_len', type=int, default=400,
+        help="The max length of audio when synthsis.")
+    parser.add_argument('--transformer_step', type=int, default=160000,
+        help="Global step to restore checkpoint of transformer in synthesis.")
+    parser.add_argument('--postnet_step', type=int, default=100000,
+        help="Global step to restore checkpoint of postnet in synthesis.")
+    parser.add_argument('--use_gpu', type=bool, default=True,
+        help="use gpu or not during training.")
+    parser.add_argument('--use_data_parallel', type=bool, default=False,
+        help="use data parallel or not during training.")
+
+    parser.add_argument('--data_path', type=str, default='./dataset/LJSpeech-1.1',
+        help="the path of dataset.")
+    parser.add_argument('--checkpoint_path', type=str, default=None,
+        help="the path to load checkpoint or pretrain model.")
+    parser.add_argument('--save_path', type=str, default='./checkpoint',
+        help="the path to save checkpoint.")
+    parser.add_argument('--log_dir', type=str, default='./log',
+        help="the directory to save tensorboard log.")
+    parser.add_argument('--sample_path', type=str, default='./log',
+        help="the directory to save audio sample in synthesis.")
+    
+
+    parser.add_argument('-c', '--config', action=jsonargparse.ActionConfigFile)
diff --git a/parakeet/models/transformerTTS/preprocess.py b/parakeet/models/transformerTTS/preprocess.py
new file mode 100644
index 0000000..b128b00
--- /dev/null
+++ b/parakeet/models/transformerTTS/preprocess.py
@@ -0,0 +1,123 @@
+from pathlib import Path
+import numpy as np
+import pandas as pd
+import librosa
+
+from parakeet import g2p
+from parakeet import audio
+
+from parakeet.data.sampler import SequentialSampler, RandomSampler, BatchSampler
+from parakeet.data.dataset import Dataset
+from parakeet.data.datacargo import DataCargo
+from parakeet.data.batch import TextIDBatcher, SpecBatcher
+
+_ljspeech_processor = audio.AudioProcessor(
+    sample_rate=22050, 
+    num_mels=80, 
+    min_level_db=-100, 
+    ref_level_db=20, 
+    n_fft=2048, 
+    win_length= int(22050 * 0.05), 
+    hop_length= int(22050 * 0.0125),
+    power=1.2,
+    preemphasis=0.97,
+    signal_norm=True,
+    symmetric_norm=False,
+    max_norm=1.,
+    mel_fmin=0,
+    mel_fmax=None,
+    clip_norm=True,
+    griffin_lim_iters=60,
+    do_trim_silence=False,
+    sound_norm=False)
+
+class LJSpeech(Dataset):
+    def __init__(self, root):
+        super(LJSpeech, self).__init__()
+        assert isinstance(root, (str, Path)), "root should be a string or Path object"
+        self.root = root if isinstance(root, Path) else Path(root)
+        self.metadata = self._prepare_metadata()
+        
+    def _prepare_metadata(self):
+        csv_path = self.root.joinpath("metadata.csv")
+        metadata = pd.read_csv(csv_path, sep="|", header=None, quoting=3,
+                               names=["fname", "raw_text", "normalized_text"])
+        return metadata
+            
+    def _get_example(self, metadatum):
+        """All the code for generating an Example from a metadatum. If you want a 
+        different preprocessing pipeline, you can override this method. 
+        This method may require several processor, each of which has a lot of options.
+        In this case, you'd better pass a composed transform and pass it to the init
+        method.
+        """
+        
+        fname, raw_text, normalized_text = metadatum
+        wav_path = self.root.joinpath("wavs", fname + ".wav")
+        
+        # load -> trim -> preemphasis -> stft -> magnitude -> mel_scale -> logscale -> normalize
+        wav = _ljspeech_processor.load_wav(str(wav_path))
+        mag = _ljspeech_processor.spectrogram(wav).astype(np.float32)
+        mel = _ljspeech_processor.melspectrogram(wav).astype(np.float32)
+        phonemes = np.array(g2p.en.text_to_sequence(normalized_text), dtype=np.int64)
+        return (mag, mel, phonemes) # maybe we need to implement it as a map in the future
+
+    def __getitem__(self, index):
+        metadatum = self.metadata.iloc[index]
+        example = self._get_example(metadatum)
+        return example
+    
+    def __iter__(self):
+        for i in range(len(self)):
+            yield self[i]
+    
+    def __len__(self):
+        return len(self.metadata)
+
+
+def batch_examples(batch):
+    texts = []
+    mels = []
+    mel_inputs = []
+    text_lens = []
+    pos_texts = []
+    pos_mels = []
+    for data in batch:
+        _, mel, text = data
+        mel_inputs.append(np.concatenate([np.zeros([mel.shape[0], 1], np.float32), mel[:,:-1]], axis=-1))
+        text_lens.append(len(text))
+        pos_texts.append(np.arange(1, len(text) + 1))
+        pos_mels.append(np.arange(1, mel.shape[1] + 1))
+        mels.append(mel)
+        texts.append(text)
+    
+    # Sort by text_len in descending order
+    texts = [i for i,_ in sorted(zip(texts, text_lens), key=lambda x: x[1], reverse=True)]
+    mels = [i for i,_ in sorted(zip(mels, text_lens), key=lambda x: x[1], reverse=True)]
+    mel_inputs = [i for i,_ in sorted(zip(mel_inputs, text_lens), key=lambda x: x[1], reverse=True)]
+    pos_texts = [i for i,_ in sorted(zip(pos_texts, text_lens), key=lambda x: x[1], reverse=True)]
+    pos_mels = [i for i,_ in sorted(zip(pos_mels, text_lens), key=lambda x: x[1], reverse=True)]
+    text_lens = sorted(text_lens, reverse=True)
+
+    # Pad sequence with largest len of the batch
+    texts = TextIDBatcher(pad_id=0)(texts)
+    pos_texts = TextIDBatcher(pad_id=0)(pos_texts)
+    pos_mels = TextIDBatcher(pad_id=0)(pos_mels)
+    mels = np.transpose(SpecBatcher(pad_value=0.)(mels), axes=(0,2,1))
+    mel_inputs = np.transpose(SpecBatcher(pad_value=0.)(mel_inputs), axes=(0,2,1))
+    return (texts, mels, mel_inputs, pos_texts, pos_mels, np.array(text_lens))
+
+def batch_examples_vocoder(batch):
+    mels=[]
+    mags=[]
+    for data in batch:
+        mag, mel, _ = data
+        mels.append(mel)
+        mags.append(mag)
+
+    mels = np.transpose(SpecBatcher(pad_value=0.)(mels), axes=(0,2,1))
+    mags = np.transpose(SpecBatcher(pad_value=0.)(mags), axes=(0,2,1))
+
+    return (mels, mags)
+
+
diff --git a/parakeet/models/transformerTTS/synthesis.py b/parakeet/models/transformerTTS/synthesis.py
new file mode 100644
index 0000000..9c89d16
--- /dev/null
+++ b/parakeet/models/transformerTTS/synthesis.py
@@ -0,0 +1,67 @@
+import os
+from scipy.io.wavfile import write
+from parakeet.g2p.en import text_to_sequence
+import numpy as np
+from network import Model, ModelPostNet
+from tqdm import tqdm
+from tensorboardX import SummaryWriter
+import paddle.fluid as fluid
+import paddle.fluid.dygraph as dg
+from preprocess import _ljspeech_processor
+from pathlib import Path
+import jsonargparse
+from parse import add_config_options_to_parser
+from pprint import pprint
+
+def load_checkpoint(step, model_path):
+    model_dict, opti_dict = fluid.dygraph.load_dygraph(os.path.join(model_path, step))
+    return model_dict
+
+def synthesis(text_input, cfg):
+    place = (fluid.CUDAPlace(0) if cfg.use_gpu else fluid.CPUPlace())
+
+    # tensorboard
+    if not os.path.exists(cfg.log_dir):
+            os.mkdir(cfg.log_dir)
+    path = os.path.join(cfg.log_dir,'synthesis')
+
+    writer = SummaryWriter(path)
+
+    with dg.guard(place):
+        model = Model(cfg)
+        model_postnet = ModelPostNet(cfg)
+
+        model.set_dict(load_checkpoint(str(cfg.transformer_step), os.path.join(cfg.checkpoint_path, "transformer")))
+        model_postnet.set_dict(load_checkpoint(str(cfg.postnet_step), os.path.join(cfg.checkpoint_path, "postnet")))
+
+        # init input
+        text = np.asarray(text_to_sequence(text_input))
+        text = fluid.layers.unsqueeze(dg.to_variable(text),[0])
+        mel_input = dg.to_variable(np.zeros([1,1,80])).astype(np.float32)
+        pos_text = np.arange(1, text.shape[1]+1)
+        pos_text = fluid.layers.unsqueeze(dg.to_variable(pos_text),[0])
+        
+
+        model.eval()
+        model_postnet.eval()
+
+        pbar = tqdm(range(cfg.max_len))
+
+        for i in pbar:
+            pos_mel = np.arange(1, mel_input.shape[1]+1)
+            pos_mel = fluid.layers.unsqueeze(dg.to_variable(pos_mel),[0])
+            mel_pred, postnet_pred, attn_probs, stop_preds, attn_enc, attn_dec = model(text, mel_input, pos_text, pos_mel)
+            mel_input = fluid.layers.concat([mel_input, postnet_pred[:,-1:,:]], axis=1)
+        mag_pred = model_postnet(postnet_pred)
+
+        wav = _ljspeech_processor.inv_spectrogram(fluid.layers.transpose(fluid.layers.squeeze(mag_pred,[0]), [1,0]).numpy())
+        writer.add_audio(text_input, wav, 0, cfg.audio.sr)
+        if not os.path.exists(cfg.sample_path):
+            os.mkdir(cfg.sample_path)
+        write(os.path.join(cfg.sample_path,'test.wav'), cfg.audio.sr, wav)
+
+if __name__ == '__main__':
+    parser = jsonargparse.ArgumentParser(description="Synthesis model", formatter_class='default_argparse')
+    add_config_options_to_parser(parser)
+    cfg = parser.parse_args('-c ./config/synthesis.yaml'.split())
+    synthesis("Transformer model is so fast!", cfg)
\ No newline at end of file
diff --git a/parakeet/models/transformerTTS/train_postnet.py b/parakeet/models/transformerTTS/train_postnet.py
new file mode 100644
index 0000000..fe0f379
--- /dev/null
+++ b/parakeet/models/transformerTTS/train_postnet.py
@@ -0,0 +1,111 @@
+from network import *
+from tensorboardX import SummaryWriter
+import os
+from tqdm import tqdm
+from pathlib import Path
+import jsonargparse
+from parse import add_config_options_to_parser
+from pprint import pprint
+from parakeet.models.dataloader.jlspeech import LJSpeechLoader
+
+class MyDataParallel(dg.parallel.DataParallel):
+    """
+    A data parallel proxy for model.
+    """
+
+    def __init__(self, layers, strategy):
+        super(MyDataParallel, self).__init__(layers, strategy)
+
+    def __getattr__(self, key):
+        if key in self.__dict__:
+            return object.__getattribute__(self, key)
+        elif key is "_layers":
+            return object.__getattribute__(self, "_sub_layers")["_layers"]
+        else:
+            return getattr(
+                object.__getattribute__(self, "_sub_layers")["_layers"], key)
+
+
+def main(cfg):
+    
+    local_rank = dg.parallel.Env().local_rank if cfg.use_data_parallel else 0
+    nranks = dg.parallel.Env().nranks if cfg.use_data_parallel else 1
+    
+    if local_rank == 0:
+        # Print the whole config setting.
+        pprint(jsonargparse.namespace_to_dict(cfg))
+
+    global_step = 0
+    place = (fluid.CUDAPlace(dg.parallel.Env().dev_id)
+             if cfg.use_data_parallel else fluid.CUDAPlace(0)
+             if cfg.use_gpu else fluid.CPUPlace())
+    
+    if not os.path.exists(cfg.log_dir):
+            os.mkdir(cfg.log_dir)
+    path = os.path.join(cfg.log_dir,'postnet')
+
+    writer = SummaryWriter(path) if local_rank == 0 else None
+
+    with dg.guard(place):   
+        model = ModelPostNet(cfg)
+
+        model.train()
+        optimizer = fluid.optimizer.AdamOptimizer(learning_rate=dg.NoamDecay(1/(cfg.warm_up_step *( cfg.lr ** 2)), cfg.warm_up_step),
+                                                  parameter_list=model.parameters())
+
+
+        if cfg.checkpoint_path is not None:
+            model_dict, opti_dict = fluid.dygraph.load_dygraph(cfg.checkpoint_path)
+            model.set_dict(model_dict)
+            optimizer.set_dict(opti_dict)
+            print("load checkpoint!!!")
+
+        if cfg.use_data_parallel:
+            strategy = dg.parallel.prepare_context()
+            model = MyDataParallel(model, strategy)
+
+        reader = LJSpeechLoader(cfg, nranks, local_rank, is_vocoder=True).reader()
+
+        for epoch in range(cfg.epochs):
+            pbar = tqdm(reader)
+            for i, data in enumerate(pbar):
+                pbar.set_description('Processing at epoch %d'%epoch)
+                mel, mag = data
+                mag = dg.to_variable(mag.numpy())
+                mel = dg.to_variable(mel.numpy())
+                global_step += 1
+
+                mag_pred = model(mel)
+                loss = layers.mean(layers.abs(layers.elementwise_sub(mag_pred, mag)))
+                
+                if cfg.use_data_parallel:
+                    loss = model.scale_loss(loss)
+                    loss.backward()
+                    model.apply_collective_grads()
+                else:
+                    loss.backward()
+                optimizer.minimize(loss, grad_clip = fluid.dygraph_grad_clip.GradClipByGlobalNorm(cfg.grad_clip_thresh))
+                print("===============",model.pre_proj.conv.weight.numpy())
+                print("===============",model.pre_proj.conv.weight.gradient())
+                model.clear_gradients()
+                
+                if local_rank==0:
+                    writer.add_scalars('training_loss',{
+                        'loss':loss.numpy(),
+                    }, global_step)
+
+                    if global_step % cfg.save_step == 0:
+                        if not os.path.exists(cfg.save_path):
+                            os.mkdir(cfg.save_path)
+                        save_path = os.path.join(cfg.save_path,'postnet/%d' % global_step)
+                        dg.save_dygraph(model.state_dict(), save_path)
+                        dg.save_dygraph(optimizer.state_dict(), save_path)
+
+        if local_rank==0:
+            writer.close()
+
+if __name__ == '__main__':
+    parser = jsonargparse.ArgumentParser(description="Train postnet model", formatter_class='default_argparse')
+    add_config_options_to_parser(parser)
+    cfg = parser.parse_args('-c ./config/train_postnet.yaml'.split())
+    main(cfg)
\ No newline at end of file
diff --git a/parakeet/models/transformerTTS/train_transformer.py b/parakeet/models/transformerTTS/train_transformer.py
new file mode 100644
index 0000000..8b177cd
--- /dev/null
+++ b/parakeet/models/transformerTTS/train_transformer.py
@@ -0,0 +1,150 @@
+import os
+from tqdm import tqdm
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+from network import *
+from tensorboardX import SummaryWriter
+from pathlib import Path
+import jsonargparse
+from parse import add_config_options_to_parser
+from pprint import pprint
+from matplotlib import cm
+from parakeet.modules.utils import cross_entropy
+from parakeet.models.dataloader.jlspeech import LJSpeechLoader
+
+class MyDataParallel(dg.parallel.DataParallel):
+    """
+    A data parallel proxy for model.
+    """
+
+    def __init__(self, layers, strategy):
+        super(MyDataParallel, self).__init__(layers, strategy)
+
+    def __getattr__(self, key):
+        if key in self.__dict__:
+            return object.__getattribute__(self, key)
+        elif key is "_layers":
+            return object.__getattribute__(self, "_sub_layers")["_layers"]
+        else:
+            return getattr(
+                object.__getattribute__(self, "_sub_layers")["_layers"], key)
+
+
+def main(cfg):
+    local_rank = dg.parallel.Env().local_rank if cfg.use_data_parallel else 0
+    nranks = dg.parallel.Env().nranks if cfg.use_data_parallel else 1
+
+    fluid.default_startup_program().random_seed = 1
+    fluid.default_main_program().random_seed = 1
+
+    if local_rank == 0:
+        # Print the whole config setting.
+        pprint(jsonargparse.namespace_to_dict(cfg))
+
+    global_step = 0
+    place = (fluid.CUDAPlace(dg.parallel.Env().dev_id)
+             if cfg.use_data_parallel else fluid.CUDAPlace(0)
+             if cfg.use_gpu else fluid.CPUPlace())
+
+    if not os.path.exists(cfg.log_dir):
+            os.mkdir(cfg.log_dir)
+    path = os.path.join(cfg.log_dir,'transformer')
+
+    writer = SummaryWriter(path) if local_rank == 0 else None
+    
+    with dg.guard(place):
+        model = TransformerTTS(cfg)
+
+        model.train()
+        optimizer = fluid.optimizer.AdamOptimizer(learning_rate=dg.NoamDecay(1/(cfg.warm_up_step *( cfg.lr ** 2)), cfg.warm_up_step), 
+                                                  parameter_list=model.parameters())
+        
+        reader = LJSpeechLoader(cfg, nranks, local_rank).reader()
+        
+        if cfg.checkpoint_path is not None:
+            model_dict, opti_dict = fluid.dygraph.load_dygraph(cfg.checkpoint_path)
+            model.set_dict(model_dict)
+            optimizer.set_dict(opti_dict)
+            print("load checkpoint!!!")
+
+        if cfg.use_data_parallel:
+            strategy = dg.parallel.prepare_context()
+            model = MyDataParallel(model, strategy)
+        
+        for epoch in range(cfg.epochs):
+            pbar = tqdm(reader)
+            
+
+            for i, data in enumerate(pbar):
+                pbar.set_description('Processing at epoch %d'%epoch)
+                character, mel, mel_input, pos_text, pos_mel, text_length = data
+
+                global_step += 1
+                
+                mel_pred, postnet_pred, attn_probs, stop_preds, attn_enc, attn_dec = model(character, mel_input, pos_text, pos_mel)
+
+                label = np.zeros(stop_preds.shape).astype(np.float32)
+                text_length = text_length.numpy()
+                for i in range(label.shape[0]):
+                    label[i][text_length[i] - 1] = 1
+                
+                mel_loss = layers.mean(layers.abs(layers.elementwise_sub(mel_pred, mel)))
+                post_mel_loss = layers.mean(layers.abs(layers.elementwise_sub(postnet_pred, mel)))
+                stop_loss = cross_entropy(stop_preds, dg.to_variable(label))
+                loss = mel_loss + post_mel_loss + stop_loss
+                
+                if local_rank==0:
+                    writer.add_scalars('training_loss', {
+                        'mel_loss':mel_loss.numpy(),
+                        'post_mel_loss':post_mel_loss.numpy(),
+                        'stop_loss':stop_loss.numpy()
+                    }, global_step)
+
+                    writer.add_scalars('alphas', {
+                        'encoder_alpha':model.encoder.alpha.numpy(),
+                        'decoder_alpha':model.decoder.alpha.numpy(),
+                    }, global_step)
+
+                    writer.add_scalar('learning_rate', optimizer._learning_rate.step().numpy(), global_step)
+
+                    if global_step % cfg.image_step == 1:
+                        for i, prob in enumerate(attn_probs):
+                            for j in range(4):
+                                    x = np.uint8(cm.viridis(prob.numpy()[j*16]) * 255)
+                                    writer.add_image('Attention_%d_0'%global_step, x, i*4+j, dataformats="HWC")
+
+                        for i, prob in enumerate(attn_enc):
+                            for j in range(4):
+                                x = np.uint8(cm.viridis(prob.numpy()[j*16]) * 255)
+                                writer.add_image('Attention_enc_%d_0'%global_step, x, i*4+j, dataformats="HWC")
+
+                        for i, prob in enumerate(attn_dec):
+                            for j in range(4):
+                                x = np.uint8(cm.viridis(prob.numpy()[j*16]) * 255)
+                                writer.add_image('Attention_dec_%d_0'%global_step, x, i*4+j, dataformats="HWC")
+                                
+                if cfg.use_data_parallel:
+                    loss = model.scale_loss(loss)
+                    loss.backward()
+                    model.apply_collective_grads()
+                else:
+                    loss.backward()
+                optimizer.minimize(loss, grad_clip = fluid.dygraph_grad_clip.GradClipByGlobalNorm(cfg.grad_clip_thresh))
+                model.clear_gradients()
+                
+                # save checkpoint
+                if local_rank==0 and global_step % cfg.save_step == 0:
+                    if not os.path.exists(cfg.save_path):
+                        os.mkdir(cfg.save_path)
+                    save_path = os.path.join(cfg.save_path,'transformer/%d' % global_step)
+                    dg.save_dygraph(model.state_dict(), save_path)
+                    dg.save_dygraph(optimizer.state_dict(), save_path)
+        if local_rank==0:
+            writer.close()
+                    
+
+if __name__ =='__main__':
+    parser = jsonargparse.ArgumentParser(description="Train TransformerTTS model", formatter_class='default_argparse')
+    add_config_options_to_parser(parser)
+    cfg = parser.parse_args('-c ./config/train_transformer.yaml'.split())
+    main(cfg)
\ No newline at end of file
diff --git a/parakeet/models/waveflow/README.md b/parakeet/models/waveflow/README.md
new file mode 100644
index 0000000..d8072b1
--- /dev/null
+++ b/parakeet/models/waveflow/README.md
@@ -0,0 +1,111 @@
+# WaveFlow with Paddle Fluid
+
+Paddle fluid implementation of [WaveFlow: A Compact Flow-based Model for Raw Audio](https://arxiv.org/abs/1912.01219).
+
+## Project Structure
+```text
+├── configs                 # yaml configuration files of preset model hyperparameters
+├── benchmark.py            # benchmark code to test the speed of batched speech synthesis
+├── data.py                 # dataset and dataloader settings for LJSpeech
+├── synthesis.py            # script for speech synthesis
+├── train.py                # script for model training
+├── utils.py                # helper functions for e.g., model checkpointing
+├── waveflow.py             # WaveFlow model high level APIs
+└── waveflow_modules.py     # WaveFlow model implementation
+```
+
+## Usage
+
+There are many hyperparameters to be tuned depending on the specification of model and dataset you are working on. 
+We provide `wavenet_ljspeech.yaml` as a hyperparameter set that works well on the LJSpeech dataset.
+
+Note that `train.py`, `synthesis.py`, and `benchmark.py` all accept a `--config` parameter. To ensure consistency, you should use the same config yaml file for both training, synthesizing and benchmarking. You can also overwrite these preset hyperparameters with command line by updating parameters after `--config`. 
+For example `--config=${yaml} --batch_size=8` can overwrite the corresponding hyperparameters in the `${yaml}` config file. For more details about these hyperparameters, check `utils.add_config_options_to_parser`.
+
+Note that you also need to specify some additional parameters for `train.py`, `synthesis.py`, and `benchmark.py`, and the details can be found in `train.add_options_to_parser`, `synthesis.add_options_to_parser`, and `benchmark.add_options_to_parser`, respectively.
+
+### Dataset
+
+Download and unzip [LJSpeech](https://keithito.com/LJ-Speech-Dataset/).
+
+```bash
+wget https://data.keithito.com/data/speech/LJSpeech-1.1.tar.bz2
+tar xjvf LJSpeech-1.1.tar.bz2
+```
+
+In this example, assume that the path of unzipped LJSpeech dataset is `./data/LJSpeech-1.1`.
+
+### Train on single GPU
+
+```bash
+export PYTHONPATH="${PYTHONPATH}:${PWD}/../../.."
+export CUDA_VISIBLE_DEVICES=0
+python -u train.py \
+    --config=./configs/waveflow_ljspeech.yaml \
+    --root=./data/LJSpeech-1.1 \
+    --name=${ModelName} --batch_size=4 \
+    --parallel=false --use_gpu=true
+```
+
+#### Save and Load checkpoints
+
+Our model will save model parameters as checkpoints in `./runs/waveflow/${ModelName}/checkpoint/` every 10000 iterations by default.
+The saved checkpoint will have the format of `step-${iteration_number}.pdparams` for model parameters and `step-${iteration_number}.pdopt` for optimizer parameters. 
+
+There are three ways to load a checkpoint and resume training (take an example that you want to load a 500000-iteration checkpoint):
+1. Use `--checkpoint=./runs/waveflow/${ModelName}/checkpoint/step-500000` to provide a specific path to load. Note that you only need to provide the base name of the parameter file, which is `step-500000`, no extension name `.pdparams` or `.pdopt` is needed. 
+2. Use `--iteration=500000`.
+3. If you don't specify either `--checkpoint` or `--iteration`, the model will automatically load the latest checkpoint in `./runs/waveflow/${ModelName}/checkpoint`.
+
+### Train on multiple GPUs
+
+```bash
+export PYTHONPATH="${PYTHONPATH}:${PWD}/../../.."
+export CUDA_VISIBLE_DEVICES=0,1,2,3
+python -u -m paddle.distributed.launch train.py \
+    --config=./configs/waveflow_ljspeech.yaml \
+    --root=./data/LJSpeech-1.1 \
+    --name=${ModelName} --parallel=true --use_gpu=true
+```
+
+Use `export CUDA_VISIBLE_DEVICES=0,1,2,3` to set the GPUs that you want to use to be visible. Then the `paddle.distributed.launch` module will use these visible GPUs to do data parallel training in multiprocessing mode.
+
+### Monitor with Tensorboard
+
+By default, the logs are saved in `./runs/waveflow/${ModelName}/logs/`. You can monitor logs by tensorboard.
+
+```bash
+tensorboard --logdir=${log_dir} --port=8888
+```
+
+### Synthesize from a checkpoint
+
+Check the [Save and load checkpoint](#save-and-load-checkpoints) section on how to load a specific checkpoint.
+The following example will automatically load the latest checkpoint:
+
+```bash
+export PYTHONPATH="${PYTHONPATH}:${PWD}/../../.."
+export CUDA_VISIBLE_DEVICES=0
+python -u synthesis.py \
+    --config=./configs/waveflow_ljspeech.yaml \
+    --root=./data/LJSpeech-1.1 \
+    --name=${ModelName} --use_gpu=true \
+    --output=./syn_audios \
+    --sample=${SAMPLE} \
+    --sigma=1.0
+```
+
+In this example, `--output` specifies where to save the synthesized audios and `--sample` specifies which sample in the valid dataset (a split from the whole LJSpeech dataset, by default contains the first 16 audio samples) to synthesize based on the mel-spectrograms computed from the ground truth sample audio, e.g., `--sample=0` means to synthesize the first audio in the valid dataset.
+
+### Benchmarking
+
+Use the following example to benchmark the speed of batched speech synthesis, which reports how many times faster than real-time:
+
+```bash
+export PYTHONPATH="${PYTHONPATH}:${PWD}/../../.."
+export CUDA_VISIBLE_DEVICES=0
+python -u benchmark.py \
+    --config=./configs/waveflow_ljspeech.yaml \
+    --root=./data/LJSpeech-1.1 \
+    --name=${ModelName} --use_gpu=true
+```
\ No newline at end of file
diff --git a/parakeet/models/waveflow/benchmark.py b/parakeet/models/waveflow/benchmark.py
new file mode 100644
index 0000000..b2949d2
--- /dev/null
+++ b/parakeet/models/waveflow/benchmark.py
@@ -0,0 +1,71 @@
+import os
+import random
+from pprint import pprint
+
+import jsonargparse
+import numpy as np
+import paddle.fluid.dygraph as dg
+from paddle import fluid
+
+import utils
+from waveflow import WaveFlow
+
+
+def add_options_to_parser(parser):
+    parser.add_argument('--model', type=str, default='waveflow',
+        help="general name of the model")
+    parser.add_argument('--name', type=str,
+        help="specific name of the training model")
+    parser.add_argument('--root', type=str,
+        help="root path of the LJSpeech dataset")
+
+    parser.add_argument('--use_gpu', type=bool, default=True,
+        help="option to use gpu training")
+
+    parser.add_argument('--iteration', type=int, default=None,
+        help=("which iteration of checkpoint to load, "
+              "default to load the latest checkpoint"))
+    parser.add_argument('--checkpoint', type=str, default=None,
+        help="path of the checkpoint to load")
+
+
+def benchmark(config):
+    pprint(jsonargparse.namespace_to_dict(config))
+
+    # Get checkpoint directory path.
+    run_dir = os.path.join("runs", config.model, config.name)
+    checkpoint_dir = os.path.join(run_dir, "checkpoint")
+
+    # Configurate device.
+    place = fluid.CUDAPlace(0) if config.use_gpu else fluid.CPUPlace()
+
+    with dg.guard(place):
+        # Fix random seed.
+        seed = config.seed
+        random.seed(seed)
+        np.random.seed(seed)
+        fluid.default_startup_program().random_seed = seed
+        fluid.default_main_program().random_seed = seed
+        print("Random Seed: ", seed)
+        
+        # Build model.
+        model = WaveFlow(config, checkpoint_dir)
+        model.build(training=False)
+
+        # Run model inference.
+        model.benchmark()
+
+
+if __name__ == "__main__":
+    # Create parser.
+    parser = jsonargparse.ArgumentParser(
+        description="Synthesize audio using WaveNet model",
+        formatter_class='default_argparse')
+    add_options_to_parser(parser)
+    utils.add_config_options_to_parser(parser)
+
+    # Parse argument from both command line and yaml config file.
+    # For conflicting updates to the same field,
+    # the preceding update will be overwritten by the following one.
+    config = parser.parse_args()
+    benchmark(config)
diff --git a/parakeet/models/waveflow/configs/waveflow_ljspeech.yaml b/parakeet/models/waveflow/configs/waveflow_ljspeech.yaml
new file mode 100644
index 0000000..d3548c4
--- /dev/null
+++ b/parakeet/models/waveflow/configs/waveflow_ljspeech.yaml
@@ -0,0 +1,24 @@
+valid_size: 16
+segment_length: 16000
+sample_rate: 22050
+fft_window_shift: 256
+fft_window_size: 1024
+fft_size: 1024
+mel_bands: 80
+mel_fmin: 0.0
+mel_fmax: 8000.0
+
+seed: 1234
+learning_rate: 0.0002
+batch_size: 8
+test_every: 2000
+save_every: 10000
+max_iterations: 3000000
+
+sigma: 1.0
+n_flows: 8
+n_group: 16
+n_layers: 8
+n_channels: 64
+kernel_h: 3
+kernel_w: 3
diff --git a/parakeet/models/waveflow/data.py b/parakeet/models/waveflow/data.py
new file mode 100644
index 0000000..d89fb7b
--- /dev/null
+++ b/parakeet/models/waveflow/data.py
@@ -0,0 +1,131 @@
+import random
+
+import librosa
+import numpy as np
+from paddle import fluid
+
+from parakeet.datasets import ljspeech
+from parakeet.data import dataset
+from parakeet.data.batch import SpecBatcher, WavBatcher
+from parakeet.data.datacargo import DataCargo
+from parakeet.data.sampler import DistributedSampler, BatchSampler
+from scipy.io.wavfile import read
+
+
+class Dataset(ljspeech.LJSpeech):
+    def __init__(self, config):
+        super(Dataset, self).__init__(config.root)
+        self.config = config
+
+    def _get_example(self, metadatum):
+        fname, _, _ = metadatum
+        wav_path = self.root.joinpath("wavs", fname + ".wav")
+
+        loaded_sr, audio = read(wav_path)
+        assert loaded_sr == self.config.sample_rate
+
+        return audio
+
+
+class Subset(dataset.Dataset): 
+    def __init__(self, dataset, indices, valid):
+        self.dataset = dataset
+        self.indices = indices
+        self.valid = valid
+        self.config = dataset.config
+
+    def get_mel(self, audio):
+        spectrogram = librosa.core.stft(
+            audio, n_fft=self.config.fft_size,
+            hop_length=self.config.fft_window_shift,
+            win_length=self.config.fft_window_size)
+        spectrogram_magnitude = np.abs(spectrogram) 
+
+        # mel_filter_bank shape: [n_mels, 1 + n_fft/2]
+        mel_filter_bank = librosa.filters.mel(
+            sr=self.config.sample_rate,
+            n_fft=self.config.fft_size,
+            n_mels=self.config.mel_bands,
+            fmin=self.config.mel_fmin,
+            fmax=self.config.mel_fmax)
+        # mel shape: [n_mels, num_frames]
+        mel = np.dot(mel_filter_bank, spectrogram_magnitude)
+
+        # Normalize mel.
+        clip_val = 1e-5
+        ref_constant = 1
+        mel = np.log(np.clip(mel, a_min=clip_val, a_max=None) * ref_constant)
+
+        return mel
+
+    def __getitem__(self, idx):
+        audio = self.dataset[self.indices[idx]]
+        segment_length = self.config.segment_length
+
+        if self.valid:
+            # whole audio for valid set
+            pass
+        else:
+            # audio shape: [len]
+            if audio.shape[0] >= segment_length:  
+                max_audio_start = audio.shape[0] - segment_length
+                audio_start = random.randint(0, max_audio_start)
+                audio = audio[audio_start : (audio_start + segment_length)]
+            else:
+                audio = np.pad(audio, (0, segment_length - audio.shape[0]),
+                    mode='constant', constant_values=0)
+
+        # Normalize audio to the [-1, 1] range.
+        audio = audio.astype(np.float32) / 32768.0
+        mel = self.get_mel(audio)
+
+        return audio, mel
+
+    def _batch_examples(self, batch):
+        audios = [sample[0] for sample in batch]
+        mels = [sample[1] for sample in batch]
+
+        audios = WavBatcher(pad_value=0.0)(audios)
+        mels = SpecBatcher(pad_value=0.0)(mels)
+
+        return audios, mels
+
+    def __len__(self):
+        return len(self.indices)
+
+
+class LJSpeech:
+    def __init__(self, config, nranks, rank):
+        place = fluid.CUDAPlace(rank) if config.use_gpu else fluid.CPUPlace()
+
+        # Whole LJSpeech dataset.
+        ds = Dataset(config)
+
+        # Split into train and valid dataset.
+        indices = list(range(len(ds)))
+        train_indices = indices[config.valid_size:]
+        valid_indices = indices[:config.valid_size]
+        random.shuffle(train_indices)
+
+        # Train dataset.
+        trainset = Subset(ds, train_indices, valid=False)
+        sampler = DistributedSampler(len(trainset), nranks, rank) 
+        total_bs = config.batch_size
+        assert total_bs % nranks == 0
+        train_sampler = BatchSampler(sampler, total_bs // nranks,
+            drop_last=True)
+        trainloader = DataCargo(trainset, batch_sampler=train_sampler)
+
+        trainreader = fluid.io.PyReader(capacity=50, return_list=True)
+        trainreader.decorate_batch_generator(trainloader, place)
+        self.trainloader = (data for _ in iter(int, 1)
+            for data in trainreader())
+
+        # Valid dataset.
+        validset = Subset(ds, valid_indices, valid=True)
+        # Currently only support batch_size = 1 for valid loader.
+        validloader = DataCargo(validset, batch_size=1, shuffle=False)
+
+        validreader = fluid.io.PyReader(capacity=20, return_list=True)
+        validreader.decorate_batch_generator(validloader, place) 
+        self.validloader = validreader
diff --git a/parakeet/models/waveflow/synthesis.py b/parakeet/models/waveflow/synthesis.py
new file mode 100644
index 0000000..e42e170
--- /dev/null
+++ b/parakeet/models/waveflow/synthesis.py
@@ -0,0 +1,85 @@
+import os
+import random
+from pprint import pprint
+
+import jsonargparse
+import numpy as np
+import paddle.fluid.dygraph as dg
+from paddle import fluid
+
+import utils
+from waveflow import WaveFlow
+
+
+def add_options_to_parser(parser):
+    parser.add_argument('--model', type=str, default='waveflow',
+        help="general name of the model")
+    parser.add_argument('--name', type=str,
+        help="specific name of the training model")
+    parser.add_argument('--root', type=str,
+        help="root path of the LJSpeech dataset")
+
+    parser.add_argument('--use_gpu', type=bool, default=True,
+        help="option to use gpu training")
+
+    parser.add_argument('--iteration', type=int, default=None,
+        help=("which iteration of checkpoint to load, "
+              "default to load the latest checkpoint"))
+    parser.add_argument('--checkpoint', type=str, default=None,
+        help="path of the checkpoint to load")
+
+    parser.add_argument('--output', type=str, default="./syn_audios",
+        help="path to write synthesized audio files")
+    parser.add_argument('--sample', type=int, default=None,
+        help="which of the valid samples to synthesize audio")
+
+
+def synthesize(config):
+    pprint(jsonargparse.namespace_to_dict(config))
+
+    # Get checkpoint directory path.
+    run_dir = os.path.join("runs", config.model, config.name)
+    checkpoint_dir = os.path.join(run_dir, "checkpoint")
+
+    # Configurate device.
+    place = fluid.CUDAPlace(0) if config.use_gpu else fluid.CPUPlace()
+
+    with dg.guard(place):
+        # Fix random seed.
+        seed = config.seed
+        random.seed(seed)
+        np.random.seed(seed)
+        fluid.default_startup_program().random_seed = seed
+        fluid.default_main_program().random_seed = seed
+        print("Random Seed: ", seed)
+        
+        # Build model.
+        model = WaveFlow(config, checkpoint_dir)
+        model.build(training=False)
+
+        # Obtain the current iteration.
+        if config.checkpoint is None:
+            if config.iteration is None:
+                iteration = utils.load_latest_checkpoint(checkpoint_dir)
+            else:
+                iteration = config.iteration
+        else:
+            iteration = int(config.checkpoint.split('/')[-1].split('-')[-1])
+
+        # Run model inference.
+        model.infer(iteration)
+
+
+if __name__ == "__main__":
+    # Create parser.
+    parser = jsonargparse.ArgumentParser(
+        description="Synthesize audio using WaveNet model",
+        formatter_class='default_argparse')
+    add_options_to_parser(parser)
+    utils.add_config_options_to_parser(parser)
+
+    # Parse argument from both command line and yaml config file.
+    # For conflicting updates to the same field,
+    # the preceding update will be overwritten by the following one.
+    config = parser.parse_args()
+    synthesize(config)
diff --git a/parakeet/models/waveflow/train.py b/parakeet/models/waveflow/train.py
new file mode 100644
index 0000000..89b787a
--- /dev/null
+++ b/parakeet/models/waveflow/train.py
@@ -0,0 +1,114 @@
+import os
+import random
+import subprocess
+import time
+from pprint import pprint
+
+import jsonargparse
+import numpy as np
+import paddle.fluid.dygraph as dg
+from paddle import fluid
+from tensorboardX import SummaryWriter
+
+import slurm
+import utils
+from waveflow import WaveFlow
+
+
+def add_options_to_parser(parser):
+    parser.add_argument('--model', type=str, default='waveflow',
+        help="general name of the model")
+    parser.add_argument('--name', type=str,
+        help="specific name of the training model")
+    parser.add_argument('--root', type=str,
+        help="root path of the LJSpeech dataset")
+
+    parser.add_argument('--parallel', type=bool, default=True,
+        help="option to use data parallel training")
+    parser.add_argument('--use_gpu', type=bool, default=True,
+        help="option to use gpu training")
+
+    parser.add_argument('--iteration', type=int, default=None,
+        help=("which iteration of checkpoint to load, "
+              "default to load the latest checkpoint"))
+    parser.add_argument('--checkpoint', type=str, default=None,
+        help="path of the checkpoint to load")
+
+
+def train(config):
+    use_gpu = config.use_gpu
+    parallel = config.parallel if use_gpu else False
+
+    # Get the rank of the current training process.
+    rank = dg.parallel.Env().local_rank if parallel else 0
+    nranks = dg.parallel.Env().nranks if parallel else 1
+
+    if rank == 0:
+        # Print the whole config setting.
+        pprint(jsonargparse.namespace_to_dict(config))
+
+    # Make checkpoint directory.
+    run_dir = os.path.join("runs", config.model, config.name)
+    checkpoint_dir = os.path.join(run_dir, "checkpoint")
+    os.makedirs(checkpoint_dir, exist_ok=True)
+
+    # Create tensorboard logger.
+    tb = SummaryWriter(os.path.join(run_dir, "logs")) \
+        if rank == 0 else None
+
+    # Configurate device
+    place = fluid.CUDAPlace(rank) if use_gpu else fluid.CPUPlace()
+
+    with dg.guard(place):
+        # Fix random seed.
+        seed = config.seed
+        random.seed(seed)
+        np.random.seed(seed)
+        fluid.default_startup_program().random_seed = seed
+        fluid.default_main_program().random_seed = seed
+        print("Random Seed: ", seed)
+
+        # Build model.
+        model = WaveFlow(config, checkpoint_dir, parallel, rank, nranks, tb)
+        model.build()
+
+        # Obtain the current iteration.
+        if config.checkpoint is None:
+            if config.iteration is None:
+                iteration = utils.load_latest_checkpoint(checkpoint_dir, rank)
+            else:
+                iteration = config.iteration
+        else:
+            iteration = int(config.checkpoint.split('/')[-1].split('-')[-1])
+
+        while iteration < config.max_iterations:
+            # Run one single training step.
+            model.train_step(iteration)
+
+            iteration += 1
+
+            if iteration % config.test_every == 0:
+                # Run validation step.
+                model.valid_step(iteration)
+
+            if rank == 0 and iteration % config.save_every == 0:
+                # Save parameters.
+                model.save(iteration)
+
+    # Close TensorBoard.
+    if rank == 0:
+        tb.close()
+
+
+if __name__ == "__main__":
+    # Create parser.
+    parser = jsonargparse.ArgumentParser(description="Train WaveFlow model",
+        formatter_class='default_argparse')
+    add_options_to_parser(parser)
+    utils.add_config_options_to_parser(parser)
+
+    # Parse argument from both command line and yaml config file.
+    # For conflicting updates to the same field, 
+    # the preceding update will be overwritten by the following one.
+    config = parser.parse_args()
+    train(config) 
diff --git a/parakeet/models/waveflow/utils.py b/parakeet/models/waveflow/utils.py
new file mode 100644
index 0000000..3baeb60
--- /dev/null
+++ b/parakeet/models/waveflow/utils.py
@@ -0,0 +1,114 @@
+import itertools
+import os
+import time
+
+import jsonargparse
+import numpy as np
+import paddle.fluid.dygraph as dg
+
+
+def add_config_options_to_parser(parser):
+    parser.add_argument('--valid_size', type=int,
+        help="size of the valid dataset")
+    parser.add_argument('--segment_length', type=int,
+        help="the length of audio clip for training")
+    parser.add_argument('--sample_rate', type=int,
+        help="sampling rate of audio data file")
+    parser.add_argument('--fft_window_shift', type=int,
+        help="the shift of fft window for each frame")
+    parser.add_argument('--fft_window_size', type=int,
+        help="the size of fft window for each frame")
+    parser.add_argument('--fft_size', type=int,
+        help="the size of fft filter on each frame")
+    parser.add_argument('--mel_bands', type=int,
+        help="the number of mel bands when calculating mel spectrograms")
+    parser.add_argument('--mel_fmin', type=float,
+        help="lowest frequency in calculating mel spectrograms")
+    parser.add_argument('--mel_fmax', type=float,
+        help="highest frequency in calculating mel spectrograms")
+
+    parser.add_argument('--seed', type=int,
+        help="seed of random initialization for the model")
+    parser.add_argument('--learning_rate', type=float)
+    parser.add_argument('--batch_size', type=int,
+        help="batch size for training")
+    parser.add_argument('--test_every', type=int,
+        help="test interval during training")
+    parser.add_argument('--save_every', type=int,
+        help="checkpointing interval during training")
+    parser.add_argument('--max_iterations', type=int,
+        help="maximum training iterations")
+
+    parser.add_argument('--sigma', type=float,
+        help="standard deviation of the latent Gaussian variable")
+    parser.add_argument('--n_flows', type=int,
+        help="number of flows")
+    parser.add_argument('--n_group', type=int,
+        help="number of adjacent audio samples to squeeze into one column")
+    parser.add_argument('--n_layers', type=int,
+        help="number of conv2d layer in one wavenet-like flow architecture")
+    parser.add_argument('--n_channels', type=int,
+        help="number of residual channels in flow")
+    parser.add_argument('--kernel_h', type=int,
+        help="height of the kernel in the conv2d layer")
+    parser.add_argument('--kernel_w', type=int,
+        help="width of the kernel in the conv2d layer")
+
+    parser.add_argument('--config', action=jsonargparse.ActionConfigFile)
+
+
+def load_latest_checkpoint(checkpoint_dir, rank=0):
+    checkpoint_path = os.path.join(checkpoint_dir, "checkpoint")
+    # Create checkpoint index file if not exist.
+    if (not os.path.isfile(checkpoint_path)) and rank == 0:
+        with open(checkpoint_path, "w") as handle:
+            handle.write("model_checkpoint_path: step-0")
+
+    # Make sure that other process waits until checkpoint file is created
+    # by process 0.
+    while not os.path.isfile(checkpoint_path):
+        time.sleep(1)
+
+    # Fetch the latest checkpoint index.
+    with open(checkpoint_path, "r") as handle:
+        latest_checkpoint = handle.readline().split()[-1]
+        iteration = int(latest_checkpoint.split("-")[-1])
+
+    return iteration
+
+
+def save_latest_checkpoint(checkpoint_dir, iteration):
+    checkpoint_path = os.path.join(checkpoint_dir, "checkpoint")
+    # Update the latest checkpoint index.
+    with open(checkpoint_path, "w") as handle:
+        handle.write("model_checkpoint_path: step-{}".format(iteration))
+
+
+def load_parameters(checkpoint_dir, rank, model, optimizer=None,
+                    iteration=None, file_path=None):
+    if file_path is None:
+        if iteration is None:
+            iteration = load_latest_checkpoint(checkpoint_dir, rank)
+        if iteration == 0:
+            return
+        file_path = "{}/step-{}".format(checkpoint_dir, iteration)
+
+    model_dict, optimizer_dict = dg.load_dygraph(file_path)
+    model.set_dict(model_dict)
+    print("[checkpoint] Rank {}: loaded model from {}".format(rank, file_path))
+    if optimizer and optimizer_dict:
+        optimizer.set_dict(optimizer_dict)
+        print("[checkpoint] Rank {}: loaded optimizer state from {}".format(
+              rank, file_path))
+
+
+def save_latest_parameters(checkpoint_dir, iteration, model, optimizer=None):
+    file_path = "{}/step-{}".format(checkpoint_dir, iteration)
+    model_dict = model.state_dict()
+    dg.save_dygraph(model_dict, file_path)
+    print("[checkpoint] Saved model to {}".format(file_path))
+
+    if optimizer:
+        opt_dict = optimizer.state_dict()
+        dg.save_dygraph(opt_dict, file_path)
+        print("[checkpoint] Saved optimzier state to {}".format(file_path))
diff --git a/parakeet/models/waveflow/waveflow.py b/parakeet/models/waveflow/waveflow.py
new file mode 100644
index 0000000..4935d42
--- /dev/null
+++ b/parakeet/models/waveflow/waveflow.py
@@ -0,0 +1,190 @@
+import itertools
+import os
+import time
+
+import numpy as np
+import paddle.fluid.dygraph as dg
+from paddle import fluid
+from scipy.io.wavfile import write
+
+import utils
+from data import LJSpeech
+from waveflow_modules import WaveFlowLoss, WaveFlowModule
+
+
+class WaveFlow():
+    def __init__(self, config, checkpoint_dir, parallel=False, rank=0,
+                 nranks=1, tb_logger=None):
+        self.config = config
+        self.checkpoint_dir = checkpoint_dir
+        self.parallel = parallel
+        self.rank = rank
+        self.nranks = nranks
+        self.tb_logger = tb_logger
+
+    def build(self, training=True):
+        config = self.config
+        dataset = LJSpeech(config, self.nranks, self.rank) 
+        self.trainloader = dataset.trainloader
+        self.validloader = dataset.validloader
+
+        waveflow = WaveFlowModule("waveflow", config)
+        
+        # Dry run once to create and initalize all necessary parameters.
+        audio = dg.to_variable(np.random.randn(1, 16000).astype(np.float32))
+        mel = dg.to_variable(
+            np.random.randn(1, config.mel_bands, 63).astype(np.float32))
+        waveflow(audio, mel)
+
+        if training:
+            optimizer = fluid.optimizer.AdamOptimizer(
+                learning_rate=config.learning_rate)
+    
+            # Load parameters.
+            utils.load_parameters(self.checkpoint_dir, self.rank,
+                                  waveflow, optimizer,
+                                  iteration=config.iteration,
+                                  file_path=config.checkpoint)
+            print("Rank {}: checkpoint loaded.".format(self.rank))
+    
+            # Data parallelism.
+            if self.parallel:
+                strategy = dg.parallel.prepare_context()
+                waveflow = dg.parallel.DataParallel(waveflow, strategy)
+    
+            self.waveflow = waveflow
+            self.optimizer = optimizer
+            self.criterion = WaveFlowLoss(config.sigma)
+
+        else:
+            # Load parameters.
+            utils.load_parameters(self.checkpoint_dir, self.rank, waveflow,
+                                  iteration=config.iteration,
+                                  file_path=config.checkpoint)
+            print("Rank {}: checkpoint loaded.".format(self.rank))
+
+            self.waveflow = waveflow
+
+    def train_step(self, iteration):
+        self.waveflow.train()
+
+        start_time = time.time()
+        audios, mels = next(self.trainloader)
+        load_time = time.time()
+
+        outputs = self.waveflow(audios, mels)
+        loss = self.criterion(outputs)
+
+        if self.parallel:
+            # loss = loss / num_trainers
+            loss = self.waveflow.scale_loss(loss)
+            loss.backward()
+            self.waveflow.apply_collective_grads()
+        else:
+            loss.backward()
+
+        self.optimizer.minimize(loss, parameter_list=self.waveflow.parameters())
+        self.waveflow.clear_gradients()
+
+        graph_time = time.time()
+
+        if self.rank == 0:
+            loss_val = float(loss.numpy()) * self.nranks
+            log = "Rank: {} Step: {:^8d} Loss: {:<8.3f} " \
+                  "Time: {:.3f}/{:.3f}".format(
+                  self.rank, iteration, loss_val,
+                  load_time - start_time, graph_time - load_time)
+            print(log)
+
+            tb = self.tb_logger
+            tb.add_scalar("Train-Loss-Rank-0", loss_val, iteration)
+
+    @dg.no_grad
+    def valid_step(self, iteration):
+        self.waveflow.eval()
+        tb = self.tb_logger
+
+        total_loss = []
+        sample_audios = []
+        start_time = time.time()
+
+        for i, batch in enumerate(self.validloader()):
+            audios, mels = batch
+            valid_outputs = self.waveflow(audios, mels)
+            valid_z, valid_log_s_list = valid_outputs
+
+            # Visualize latent z and scale log_s.
+            if self.rank == 0 and i == 0:
+                tb.add_histogram("Valid-Latent_z", valid_z.numpy(), iteration)
+                for j, valid_log_s in enumerate(valid_log_s_list):
+                    hist_name = "Valid-{}th-Flow-Log_s".format(j)
+                    tb.add_histogram(hist_name, valid_log_s.numpy(), iteration)
+
+            valid_loss = self.criterion(valid_outputs)
+            total_loss.append(float(valid_loss.numpy()))
+
+        total_time = time.time() - start_time
+        if self.rank == 0:
+            loss_val = np.mean(total_loss)
+            log = "Test | Rank: {} AvgLoss: {:<8.3f} Time {:<8.3f}".format(
+                self.rank, loss_val, total_time)
+            print(log)
+            tb.add_scalar("Valid-Avg-Loss", loss_val, iteration)
+
+    @dg.no_grad
+    def infer(self, iteration):
+        self.waveflow.eval()
+
+        config = self.config
+        sample = config.sample
+
+        output = "{}/{}/iter-{}".format(config.output, config.name, iteration)
+        os.makedirs(output, exist_ok=True)
+
+        mels_list = [mels for _, mels in self.validloader()]
+        if sample is not None:
+            mels_list = [mels_list[sample]]
+
+        for sample, mel in enumerate(mels_list):
+            filename = "{}/valid_{}.wav".format(output, sample)
+            print("Synthesize sample {}, save as {}".format(sample, filename))
+    
+            start_time = time.time()
+            audio = self.waveflow.synthesize(mel, sigma=self.config.sigma)
+            syn_time = time.time() - start_time
+    
+            audio = audio[0]
+            audio_time = audio.shape[0] / self.config.sample_rate
+            print("audio time {:.4f}, synthesis time {:.4f}".format(
+                audio_time, syn_time))
+    
+            # Denormalize audio from [-1, 1] to [-32768, 32768] int16 range.
+            audio = audio.numpy() * 32768.0
+            audio = audio.astype('int16')
+            write(filename, config.sample_rate, audio)
+
+    @dg.no_grad
+    def benchmark(self):
+        self.waveflow.eval()
+
+        mels_list = [mels for _, mels in self.validloader()]
+        mel = fluid.layers.concat(mels_list, axis=2)
+        mel = mel[:, :, :864]
+        batch_size = 8
+        mel = fluid.layers.expand(mel, [batch_size, 1, 1])
+
+        for i in range(10):
+            start_time = time.time()
+            audio = self.waveflow.synthesize(mel, sigma=self.config.sigma)
+            print("audio.shape = ", audio.shape)
+            syn_time = time.time() - start_time
+
+            audio_time = audio.shape[1] * batch_size / self.config.sample_rate
+            print("audio time {:.4f}, synthesis time {:.4f}".format(
+                audio_time, syn_time))
+            print("{} X real-time".format(audio_time / syn_time))
+
+    def save(self, iteration):
+        utils.save_latest_parameters(self.checkpoint_dir, iteration,
+                                     self.waveflow, self.optimizer)
+        utils.save_latest_checkpoint(self.checkpoint_dir, iteration)
diff --git a/parakeet/models/waveflow/waveflow_modules.py b/parakeet/models/waveflow/waveflow_modules.py
new file mode 100644
index 0000000..39cb598
--- /dev/null
+++ b/parakeet/models/waveflow/waveflow_modules.py
@@ -0,0 +1,351 @@
+import itertools
+
+import numpy as np
+import paddle.fluid.dygraph as dg
+from paddle import fluid
+from parakeet.modules import conv, modules, weight_norm
+
+
+def set_param_attr(layer, c_in=1):
+    if isinstance(layer, (weight_norm.Conv2DTranspose, weight_norm.Conv2D)):
+        k = np.sqrt(1.0 / (c_in * np.prod(layer._filter_size)))
+        weight_init = fluid.initializer.UniformInitializer(low=-k, high=k)
+        bias_init = fluid.initializer.UniformInitializer(low=-k, high=k)
+    elif isinstance(layer, dg.Conv2D):
+        weight_init = fluid.initializer.ConstantInitializer(0.0)
+        bias_init = fluid.initializer.ConstantInitializer(0.0)
+    else:
+        raise TypeError("Unsupported layer type.")
+
+    layer._param_attr = fluid.ParamAttr(initializer=weight_init)
+    layer._bias_attr = fluid.ParamAttr(initializer=bias_init)
+
+
+def unfold(x, n_group):
+    length = x.shape[-1] 
+    new_shape = x.shape[:-1] + [length // n_group, n_group]
+    return fluid.layers.reshape(x, new_shape)
+
+
+class WaveFlowLoss:
+    def __init__(self, sigma=1.0):
+        self.sigma = sigma
+
+    def __call__(self, model_output):
+        z, log_s_list = model_output
+        for i, log_s in enumerate(log_s_list):
+            if i == 0:
+                log_s_total = fluid.layers.reduce_sum(log_s)
+            else:
+                log_s_total = log_s_total + fluid.layers.reduce_sum(log_s)
+
+        loss = fluid.layers.reduce_sum(z * z) / (2 * self.sigma * self.sigma) \
+            - log_s_total
+        loss = loss / np.prod(z.shape)
+        const = 0.5 * np.log(2 * np.pi) + np.log(self.sigma)
+
+        return loss + const
+
+
+class Conditioner(dg.Layer):
+    def __init__(self, name_scope):
+        super(Conditioner, self).__init__(name_scope)
+        upsample_factors = [16, 16]
+        
+        self.upsample_conv2d = []
+        for s in upsample_factors:
+            in_channel = 1
+            conv_trans2d = modules.Conv2DTranspose(
+                self.full_name(),
+                num_filters=1,
+                filter_size=(3, 2 * s),
+                padding=(1, s // 2),
+                stride=(1, s))
+            set_param_attr(conv_trans2d, c_in=in_channel) 
+            self.upsample_conv2d.append(conv_trans2d)
+
+        for i, layer in enumerate(self.upsample_conv2d):
+            self.add_sublayer("conv2d_transpose_{}".format(i), layer)
+
+    def forward(self, x):
+        x = fluid.layers.unsqueeze(x, 1)
+        for layer in self.upsample_conv2d:
+            x = fluid.layers.leaky_relu(layer(x), alpha=0.4)
+
+        return fluid.layers.squeeze(x, [1])
+
+    def infer(self, x):
+        x = fluid.layers.unsqueeze(x, 1)
+        for layer in self.upsample_conv2d:
+            x = layer(x)
+            # Trim conv artifacts.
+            time_cutoff = layer._filter_size[1] - layer._stride[1]
+            x = fluid.layers.leaky_relu(x[:, :, :, :-time_cutoff], alpha=0.4)
+
+        return fluid.layers.squeeze(x, [1])
+
+
+class Flow(dg.Layer):
+    def __init__(self, name_scope, config): 
+        super(Flow, self).__init__(name_scope)
+        self.n_layers = config.n_layers
+        self.n_channels = config.n_channels
+        self.kernel_h = config.kernel_h
+        self.kernel_w = config.kernel_w
+
+        # Transform audio: [batch, 1, n_group, time/n_group] 
+        # => [batch, n_channels, n_group, time/n_group]
+        self.start = weight_norm.Conv2D(
+            self.full_name(),
+            num_filters=self.n_channels,
+            filter_size=(1, 1))
+        set_param_attr(self.start, c_in=1)
+
+        # Initializing last layer to 0 makes the affine coupling layers
+        # do nothing at first.  This helps with training stability
+        # output shape: [batch, 2, n_group, time/n_group]
+        self.end = dg.Conv2D(
+            self.full_name(),
+            num_filters=2,
+            filter_size=(1, 1))
+        set_param_attr(self.end)
+
+        # receiptive fileds: (kernel - 1) * sum(dilations) + 1 >= squeeze
+        dilation_dict = {8:   [1, 1, 1, 1, 1, 1, 1, 1],
+                         16:  [1, 1, 1, 1, 1, 1, 1, 1],
+                         32:  [1, 2, 4, 1, 2, 4, 1, 2],
+                         64:  [1, 2, 4, 8, 16, 1, 2, 4],
+                         128: [1, 2, 4, 8, 16, 32, 64, 1]}
+        self.dilation_h_list = dilation_dict[config.n_group]
+
+        self.in_layers = []
+        self.cond_layers = []
+        self.res_skip_layers = []
+        for i in range(self.n_layers):
+            dilation_h = self.dilation_h_list[i]
+            dilation_w = 2 ** i
+
+            in_layer = weight_norm.Conv2D(
+                self.full_name(),
+                num_filters=2 * self.n_channels,
+                filter_size=(self.kernel_h, self.kernel_w),
+                dilation=(dilation_h, dilation_w))
+            set_param_attr(in_layer, c_in=self.n_channels)
+            self.in_layers.append(in_layer)
+
+            cond_layer = weight_norm.Conv2D(
+                self.full_name(),
+                num_filters=2 * self.n_channels,
+                filter_size=(1, 1))
+            set_param_attr(cond_layer, c_in=config.mel_bands)
+            self.cond_layers.append(cond_layer)
+
+            if i < self.n_layers - 1:
+                res_skip_channels = 2 * self.n_channels
+            else:
+                res_skip_channels = self.n_channels
+            res_skip_layer = weight_norm.Conv2D(
+                self.full_name(),
+                num_filters=res_skip_channels,
+                filter_size=(1, 1))
+            set_param_attr(res_skip_layer, c_in=self.n_channels)
+            self.res_skip_layers.append(res_skip_layer)
+
+            self.add_sublayer("in_layer_{}".format(i), in_layer)
+            self.add_sublayer("cond_layer_{}".format(i), cond_layer)
+            self.add_sublayer("res_skip_layer_{}".format(i), res_skip_layer)
+
+    def forward(self, audio, mel):
+        # audio: [bs, 1, n_group, time/group]
+        # mel: [bs, mel_bands, n_group, time/n_group]
+        audio = self.start(audio)
+
+        for i in range(self.n_layers):
+            dilation_h = self.dilation_h_list[i]
+            dilation_w = 2 ** i
+
+            # Pad height dim (n_group): causal convolution
+            # Pad width dim (time): dialated non-causal convolution
+            pad_top, pad_bottom = (self.kernel_h - 1) * dilation_h, 0
+            pad_left = pad_right = int((self.kernel_w-1) * dilation_w / 2)
+            audio_pad = fluid.layers.pad2d(audio, 
+                paddings=[pad_top, pad_bottom, pad_left, pad_right])
+
+            hidden = self.in_layers[i](audio_pad)
+            cond_hidden = self.cond_layers[i](mel)
+            in_acts = hidden + cond_hidden
+            out_acts = fluid.layers.tanh(in_acts[:, :self.n_channels, :]) * \
+                fluid.layers.sigmoid(in_acts[:, self.n_channels:, :])
+            res_skip_acts = self.res_skip_layers[i](out_acts)
+
+            if i < self.n_layers - 1:
+                audio += res_skip_acts[:, :self.n_channels, :, :]
+                skip_acts = res_skip_acts[:, self.n_channels:, :, :]
+            else:
+                skip_acts = res_skip_acts
+
+            if i == 0:
+                output = skip_acts
+            else:
+                output += skip_acts
+
+        return self.end(output)
+
+    def infer(self, audio, mel, queues):
+        audio = self.start(audio)
+
+        for i in range(self.n_layers):
+            dilation_h = self.dilation_h_list[i]
+            dilation_w = 2 ** i
+
+            state_size = dilation_h * (self.kernel_h - 1)
+            queue = queues[i]
+
+            if len(queue) == 0:
+                for j in range(state_size):
+                    queue.append(fluid.layers.zeros_like(audio))
+
+            state = queue[0:state_size]
+            state = fluid.layers.concat([*state, audio], axis=2)
+
+            queue.pop(0)
+            queue.append(audio)
+
+            # Pad height dim (n_group): causal convolution
+            # Pad width dim (time): dialated non-causal convolution
+            pad_top, pad_bottom = 0, 0
+            pad_left = int((self.kernel_w-1) * dilation_w / 2)
+            pad_right = int((self.kernel_w-1) * dilation_w / 2)
+            state = fluid.layers.pad2d(state,
+                paddings=[pad_top, pad_bottom, pad_left, pad_right])
+
+            hidden = self.in_layers[i](state)
+            cond_hidden = self.cond_layers[i](mel)
+            in_acts = hidden + cond_hidden
+            out_acts = fluid.layers.tanh(in_acts[:, :self.n_channels, :]) * \
+                fluid.layers.sigmoid(in_acts[:, self.n_channels:, :])
+            res_skip_acts = self.res_skip_layers[i](out_acts)
+
+            if i < self.n_layers - 1:
+                audio += res_skip_acts[:, :self.n_channels, :, :]
+                skip_acts = res_skip_acts[:, self.n_channels:, :, :]
+            else:
+                skip_acts = res_skip_acts
+
+            if i == 0:
+                output = skip_acts
+            else:
+                output += skip_acts
+
+        return self.end(output)
+
+
+class WaveFlowModule(dg.Layer):
+    def __init__(self, name_scope, config):
+        super(WaveFlowModule, self).__init__(name_scope)
+        self.n_flows = config.n_flows
+        self.n_group = config.n_group
+        self.n_layers = config.n_layers
+        assert self.n_group % 2 == 0
+        assert self.n_flows % 2 == 0
+
+        self.conditioner = Conditioner(self.full_name())
+        self.flows = []
+        for i in range(self.n_flows):
+            flow = Flow(self.full_name(), config)
+            self.flows.append(flow)
+            self.add_sublayer("flow_{}".format(i), flow) 
+
+        self.perms = []
+        half = self.n_group // 2
+        for i in range(self.n_flows):
+            perm = list(range(self.n_group))
+            if i < self.n_flows // 2:
+                perm = perm[::-1]
+            else:
+                perm[:half] = reversed(perm[:half])
+                perm[half:] = reversed(perm[half:])
+            self.perms.append(perm)
+        
+    def forward(self, audio, mel):
+        mel = self.conditioner(mel)
+        assert mel.shape[2] >= audio.shape[1]
+        # Prune out the tail of audio/mel so that time/n_group == 0.
+        pruned_len = audio.shape[1] // self.n_group * self.n_group
+
+        if audio.shape[1] > pruned_len:
+            audio = audio[:, :pruned_len]
+        if mel.shape[2] > pruned_len:
+            mel = mel[:, :, :pruned_len]
+        
+        # From [bs, mel_bands, time] to [bs, mel_bands, n_group, time/n_group]
+        mel = fluid.layers.transpose(unfold(mel, self.n_group), [0, 1, 3, 2])
+        # From [bs, time] to [bs, n_group, time/n_group]
+        audio = fluid.layers.transpose(unfold(audio, self.n_group), [0, 2, 1])
+        # [bs, 1, n_group, time/n_group] 
+        audio = fluid.layers.unsqueeze(audio, 1)
+
+        log_s_list = []
+        for i in range(self.n_flows):
+            inputs = audio[:, :, :-1, :]
+            conds = mel[:, :, 1:, :]
+            outputs = self.flows[i](inputs, conds)
+            log_s = outputs[:, :1, :, :]
+            b = outputs[:, 1:, :, :]
+            log_s_list.append(log_s)
+
+            audio_0 = audio[:, :, :1, :]
+            audio_out = audio[:, :, 1:, :] * fluid.layers.exp(log_s) + b
+            audio = fluid.layers.concat([audio_0, audio_out], axis=2)
+
+            # Permute over the height dim.
+            audio_slices = [audio[:, :, j, :] for j in self.perms[i]]
+            audio = fluid.layers.stack(audio_slices, axis=2)
+            mel_slices = [mel[:, :, j, :] for j in self.perms[i]]
+            mel = fluid.layers.stack(mel_slices, axis=2)
+
+        z = fluid.layers.squeeze(audio, [1])
+
+        return z, log_s_list
+
+    def synthesize(self, mel, sigma=1.0):
+        mel = self.conditioner.infer(mel)
+        # From [bs, mel_bands, time] to [bs, mel_bands, n_group, time/n_group]
+        mel = fluid.layers.transpose(unfold(mel, self.n_group), [0, 1, 3, 2])
+
+        audio = fluid.layers.gaussian_random(
+            shape=[mel.shape[0], 1, mel.shape[2], mel.shape[3]], std=sigma)
+
+        for i in reversed(range(self.n_flows)):
+            # Permute over the height dimension.
+            audio_slices = [audio[:, :, j, :] for j in self.perms[i]]
+            audio = fluid.layers.stack(audio_slices, axis=2)
+            mel_slices = [mel[:, :, j, :] for j in self.perms[i]]
+            mel = fluid.layers.stack(mel_slices, axis=2)
+
+            audio_list = []
+            audio_0 = audio[:, :, 0:1, :]
+            audio_list.append(audio_0)
+            audio_h = audio_0
+            queues = [[] for _ in range(self.n_layers)]
+
+            for h in range(1, self.n_group):
+                inputs = audio_h
+                conds = mel[:, :, h:(h+1), :]
+                outputs = self.flows[i].infer(inputs, conds, queues)
+
+                log_s = outputs[:, 0:1, :, :]
+                b = outputs[:, 1:, :, :]
+                audio_h = (audio[:, :, h:(h+1), :] - b) / \
+                    fluid.layers.exp(log_s)
+                audio_list.append(audio_h)
+
+            audio = fluid.layers.concat(audio_list, axis=2)
+
+        # audio: [bs, n_group, time/n_group]
+        audio = fluid.layers.squeeze(audio, [1])
+        # audio: [bs, time]
+        audio = fluid.layers.reshape(
+            fluid.layers.transpose(audio, [0, 2, 1]), [audio.shape[0], -1])
+
+        return audio
diff --git a/parakeet/modules/dynamicGRU.py b/parakeet/modules/dynamicGRU.py
new file mode 100644
index 0000000..e84c598
--- /dev/null
+++ b/parakeet/modules/dynamicGRU.py
@@ -0,0 +1,52 @@
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+
+class DynamicGRU(dg.Layer):
+    def __init__(self,
+                 size,
+                 param_attr=None,
+                 bias_attr=None,
+                 is_reverse=False,
+                 gate_activation='sigmoid',
+                 candidate_activation='tanh',
+                 h_0=None,
+                 origin_mode=False,
+                 init_size=None):
+        super(DynamicGRU, self).__init__()
+        self.gru_unit = dg.GRUUnit(
+            size * 3,
+            param_attr=param_attr,
+            bias_attr=bias_attr,
+            activation=candidate_activation,
+            gate_activation=gate_activation,
+            origin_mode=origin_mode)
+        self.size = size
+        self.h_0 = h_0
+        self.is_reverse = is_reverse
+
+    def forward(self, inputs):
+        """
+        Dynamic GRU block.
+        
+        Args:
+            input (Variable): Shape(B, T, C), dtype: float32. The input value.
+        Returns:
+            output (Variable), Shape(B, T, C), the result compute by GRU.
+        """
+        hidden = self.h_0
+        res = []
+        for i in range(inputs.shape[1]):
+            if self.is_reverse:
+                i = inputs.shape[1] - 1 - i
+            input_ = inputs[:, i:i + 1, :]
+            input_ = layers.reshape(
+                input_, [-1, input_.shape[2]], inplace=False)
+            hidden, reset, gate = self.gru_unit(input_, hidden)
+            hidden_ = layers.reshape(
+                hidden, [-1, 1, hidden.shape[1]], inplace=False)
+            res.append(hidden_)
+        if self.is_reverse:
+            res = res[::-1]
+        res = layers.concat(res, axis=1)
+        return res
+
diff --git a/parakeet/modules/feed_forward.py b/parakeet/modules/feed_forward.py
new file mode 100644
index 0000000..452c482
--- /dev/null
+++ b/parakeet/modules/feed_forward.py
@@ -0,0 +1,52 @@
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+import paddle.fluid as fluid
+import math
+from parakeet.modules.layers import Conv
+
+
+class PositionwiseFeedForward(dg.Layer):
+    ''' A two-feed-forward-layer module '''
+    def __init__(self, d_in, num_hidden, filter_size, padding=0, use_cudnn=True, dropout=0.1):
+        super(PositionwiseFeedForward, self).__init__()
+        self.num_hidden = num_hidden
+        self.use_cudnn = use_cudnn
+        self.dropout = dropout
+
+        self.w_1 = Conv(in_channels = d_in, 
+                        out_channels = num_hidden, 
+                        filter_size = filter_size,
+                        padding=padding,
+                        use_cudnn = use_cudnn,
+                        data_format = "NTC")
+        
+        self.w_2 = Conv(in_channels = num_hidden,
+                        out_channels = d_in,
+                        filter_size = filter_size,
+                        padding=padding,
+                        use_cudnn = use_cudnn,
+                        data_format = "NTC")
+        self.layer_norm = dg.LayerNorm(d_in)
+
+    def forward(self, input):
+        """
+        Feed Forward Network.
+        
+        Args:
+            input (Variable): Shape(B, T, C), dtype: float32. The input value.
+        Returns:
+            output (Variable), Shape(B, T, C), the result after FFN.
+        """
+        #FFN Networt
+        x = self.w_2(layers.relu(self.w_1(input)))
+        
+        # dropout
+        x = layers.dropout(x, self.dropout)
+
+        # residual connection
+        x = x + input
+        
+        #layer normalization
+        output = self.layer_norm(x)
+
+        return output
\ No newline at end of file
diff --git a/parakeet/modules/layers.py b/parakeet/modules/layers.py
new file mode 100644
index 0000000..29a10db
--- /dev/null
+++ b/parakeet/modules/layers.py
@@ -0,0 +1,158 @@
+import math
+import numpy as np
+
+import paddle
+from paddle import fluid
+import paddle.fluid.dygraph as dg
+
+
+class Conv(dg.Layer):
+    def __init__(self, in_channels, out_channels, filter_size=1,
+                padding=0, dilation=1, stride=1, use_cudnn=True, 
+                data_format="NCT", is_bias=True):
+        super(Conv, self).__init__()
+        self.in_channels = in_channels
+        self.out_channels = out_channels
+        self.filter_size = filter_size
+        self.padding = padding
+        self.dilation = dilation
+        self.stride = stride
+        self.use_cudnn = use_cudnn
+        self.data_format = data_format
+        self.is_bias = is_bias
+
+        self.weight_attr = fluid.ParamAttr(initializer=fluid.initializer.XavierInitializer())
+        self.bias_attr = None
+        if is_bias is not False:
+            k = math.sqrt(1 / in_channels)
+            self.bias_attr = fluid.ParamAttr(initializer=fluid.initializer.Uniform(low=-k, high=k)) 
+        
+        self.conv = Conv1D( in_channels = in_channels,
+                            out_channels = out_channels,
+                            filter_size = filter_size,
+                            padding = padding,
+                            dilation = dilation,
+                            stride = stride,
+                            param_attr = self.weight_attr,
+                            bias_attr = self.bias_attr,
+                            use_cudnn = use_cudnn,
+                            data_format = data_format)
+
+    def forward(self, x):
+        x = self.conv(x)
+        return x
+
+class Conv1D(dg.Layer):
+    """
+    A convolution 1D block implemented with Conv2D. Form simplicity and 
+    ensuring the output has the same length as the input, it does not allow 
+    stride > 1.
+    """
+
+    def __init__(self,
+                 in_channels,
+                 out_channels,
+                 filter_size=3,
+                 padding=0,
+                 dilation=1,
+                 stride=1,
+                 groups=None,
+                 param_attr=None,
+                 bias_attr=None,
+                 use_cudnn=True,
+                 act=None,
+                 data_format='NCT',
+                 dtype="float32"):
+        super(Conv1D, self).__init__(dtype=dtype)
+
+        self.padding = padding
+        self.in_channels = in_channels
+        self.num_filters = out_channels
+        self.filter_size = filter_size
+        self.stride = stride
+        self.dilation = dilation
+        self.padding = padding
+        self.act = act
+        self.data_format = data_format
+
+        self.conv = dg.Conv2D(
+            num_channels=in_channels,
+            num_filters=out_channels,
+            filter_size=(1, filter_size),
+            stride=(1, stride),
+            dilation=(1, dilation),
+            padding=(0, padding),
+            groups=groups,
+            param_attr=param_attr,
+            bias_attr=bias_attr,
+            use_cudnn=use_cudnn,
+            act=act,
+            dtype=dtype)
+
+    def forward(self, x):
+        """
+        Args:
+            x (Variable): Shape(B, C_in, 1, T), the input, where C_in means
+                input channels.
+        Returns:
+            x (Variable): Shape(B, C_out, 1, T), the outputs, where C_out means
+                output channels (num_filters).
+        """
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        x = fluid.layers.unsqueeze(x, [2])
+        x = self.conv(x)
+        x = fluid.layers.squeeze(x, [2])
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        return x
+
+class Pool1D(dg.Layer):
+    """
+    A Pool 1D block implemented with Pool2D.
+    """
+    def __init__(self,
+                 pool_size=-1, 
+                 pool_type='max', 
+                 pool_stride=1, 
+                 pool_padding=0, 
+                 global_pooling=False, 
+                 use_cudnn=True, 
+                 ceil_mode=False, 
+                 exclusive=True,
+                 data_format='NCT'):
+        super(Pool1D, self).__init__()
+        self.pool_size = pool_size
+        self.pool_type = pool_type
+        self.pool_stride = pool_stride
+        self.pool_padding = pool_padding
+        self.global_pooling = global_pooling
+        self.use_cudnn = use_cudnn
+        self.ceil_mode = ceil_mode
+        self.exclusive = exclusive
+        self.data_format = data_format
+
+
+        self.pool2d = dg.Pool2D([1,pool_size], pool_type = pool_type,
+                                pool_stride = [1,pool_stride], pool_padding = [0, pool_padding],
+                                global_pooling = global_pooling, use_cudnn = use_cudnn,
+                                ceil_mode = ceil_mode, exclusive = exclusive)
+
+    
+    def forward(self, x):
+        """
+        Args:
+            x (Variable): Shape(B, C_in, 1, T), the input, where C_in means
+                input channels.
+        Returns:
+            x (Variable): Shape(B, C_out, 1, T), the outputs, where C_out means
+                output channels (num_filters).
+        """
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        x = fluid.layers.unsqueeze(x, [2])
+        x = self.pool2d(x)
+        x = fluid.layers.squeeze(x, [2])
+        if self.data_format == 'NTC':
+            x = fluid.layers.transpose(x, [0, 2, 1])
+        return x
diff --git a/parakeet/modules/multihead_attention.py b/parakeet/modules/multihead_attention.py
new file mode 100644
index 0000000..b2592bb
--- /dev/null
+++ b/parakeet/modules/multihead_attention.py
@@ -0,0 +1,112 @@
+import math
+import numpy as np
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+
+class ScaledDotProductAttention(dg.Layer):
+    def __init__(self, d_key):
+        super(ScaledDotProductAttention, self).__init__()
+
+        self.d_key = d_key
+    
+    # please attention this mask is diff from pytorch
+    def forward(self, key, value, query, mask=None, query_mask=None, dropout=0.1):
+        """
+        Scaled Dot Product Attention.
+        
+        Args:
+            key (Variable): Shape(B, T, C), dtype: float32. The input key of attention.
+            value (Variable): Shape(B, T, C), dtype: float32. The input value of attention.
+            query (Variable): Shape(B, T, C), dtype: float32. The input query of attention.
+            mask (Variable): Shape(B, len_q, len_k), dtype: float32. The mask of key.
+            query_mask (Variable): Shape(B, len_q, 1), dtype: float32. The mask of query.
+            dropout (Constant): dtype: float32. The probability of dropout.
+        Returns:
+            result (Variable), Shape(B, T, C), the result of mutihead attention.
+            attention (Variable), Shape(n_head * B, T, C), the attention of key.
+        """
+        # Compute attention score
+        attention = layers.matmul(query, key, transpose_y=True) #transpose the last dim in y
+        attention = attention / math.sqrt(self.d_key)
+
+        # Mask key to ignore padding
+        if mask is not None:
+            attention = attention * mask
+            mask = (mask == 0).astype(np.float32) * (-2 ** 32 + 1)
+            attention = attention + mask
+            
+
+        attention = layers.softmax(attention)
+        attention = layers.dropout(attention, dropout)
+        # Mask query to ignore padding
+        if query_mask is not None:
+            attention = attention * query_mask
+        
+        result = layers.matmul(attention, value)
+        return result, attention
+
+class MultiheadAttention(dg.Layer):
+    def __init__(self, num_hidden, d_k, d_q, num_head=4, dropout=0.1):
+        super(MultiheadAttention, self).__init__()
+        self.num_hidden = num_hidden
+        self.num_head = num_head
+        self.d_k = d_k
+        self.d_q = d_q
+        self.dropout = dropout
+
+        self.key = dg.Linear(num_hidden, num_head * d_k)
+        self.value = dg.Linear(num_hidden, num_head * d_k)
+        self.query = dg.Linear(num_hidden, num_head * d_q)
+
+        self.scal_attn = ScaledDotProductAttention(d_k)
+
+        self.fc = dg.Linear(num_head * d_q, num_hidden)
+
+        self.layer_norm = dg.LayerNorm(num_hidden)
+
+    def forward(self, key, value, query_input, mask=None, query_mask=None):
+        """
+        Multihead Attention.
+        
+        Args:
+            key (Variable): Shape(B, T, C), dtype: float32. The input key of attention.
+            value (Variable): Shape(B, T, C), dtype: float32. The input value of attention.
+            query_input (Variable): Shape(B, T, C), dtype: float32. The input query of attention.
+            mask (Variable): Shape(B, len_q, len_k), dtype: float32. The mask of key.
+            query_mask (Variable): Shape(B, len_q, 1), dtype: float32. The mask of query.
+        Returns:
+            result (Variable), Shape(B, T, C), the result of mutihead attention.
+            attention (Variable), Shape(n_head * B, T, C), the attention of key.
+        """
+        batch_size = key.shape[0]
+        seq_len_key = key.shape[1]
+        seq_len_query = query_input.shape[1]
+
+        # repeat masks h times
+        if query_mask is not None:
+            query_mask = layers.expand(query_mask, [self.num_head, 1, seq_len_key])
+        if mask is not None:
+            mask = layers.expand(mask, (self.num_head, 1, 1))
+        
+        
+        # Make multihead attention
+        # key & value.shape = (batch_size, seq_len, feature)(feature = num_head * num_hidden_per_attn)
+        key = layers.reshape(self.key(key), [batch_size, seq_len_key, self.num_head, self.d_k])
+        value = layers.reshape(self.value(value), [batch_size, seq_len_key, self.num_head, self.d_k])
+        query = layers.reshape(self.query(query_input), [batch_size, seq_len_query, self.num_head, self.d_q])
+
+        key = layers.reshape(layers.transpose(key, [2, 0, 1, 3]), [-1, seq_len_key, self.d_k])
+        value = layers.reshape(layers.transpose(value, [2, 0, 1, 3]), [-1, seq_len_key, self.d_k])
+        query = layers.reshape(layers.transpose(query, [2, 0, 1, 3]), [-1, seq_len_query, self.d_q])
+        
+        result, attention = self.scal_attn(key, value, query, mask=mask, query_mask=query_mask)
+        
+        # concat all multihead result
+        result = layers.reshape(result, [self.num_head, batch_size, seq_len_query, self.d_q])
+        result = layers.reshape(layers.transpose(result, [1,2,0,3]),[batch_size, seq_len_query, -1])
+        
+        result = layers.dropout(self.fc(result), self.dropout)
+        result = result + query_input
+        
+        result = self.layer_norm(result)
+        return result, attention
\ No newline at end of file
diff --git a/parakeet/modules/post_convnet.py b/parakeet/modules/post_convnet.py
new file mode 100644
index 0000000..559d70e
--- /dev/null
+++ b/parakeet/modules/post_convnet.py
@@ -0,0 +1,75 @@
+import paddle.fluid.dygraph as dg
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+from parakeet.modules.layers import Conv
+
+class PostConvNet(dg.Layer):
+    def __init__(self, 
+                 n_mels=80,
+                 num_hidden=512,
+                 filter_size=5,
+                 padding=0,
+                 num_conv=5,
+                 outputs_per_step=1,
+                 use_cudnn=True,
+                 dropout=0.1):
+        super(PostConvNet, self).__init__()
+        
+        self.dropout = dropout
+        self.conv_list = []
+        self.conv_list.append(Conv(in_channels = n_mels * outputs_per_step,
+                            out_channels = num_hidden,
+                            filter_size = filter_size,
+                            padding = padding,
+                            use_cudnn = use_cudnn,
+                            data_format = "NCT"))
+
+        for _ in range(1, num_conv-1):
+            self.conv_list.append(Conv(in_channels = num_hidden,
+                                out_channels = num_hidden,
+                                filter_size = filter_size,
+                                padding = padding,
+                                use_cudnn = use_cudnn,
+                                data_format = "NCT") )
+        
+        self.conv_list.append(Conv(in_channels = num_hidden,
+                            out_channels = n_mels * outputs_per_step,
+                            filter_size = filter_size,
+                            padding = padding,
+                            use_cudnn = use_cudnn,
+                            data_format = "NCT"))
+
+        for i, layer in enumerate(self.conv_list):
+            self.add_sublayer("conv_list_{}".format(i), layer)
+
+        self.batch_norm_list = [dg.BatchNorm(num_hidden, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW') for _ in range(num_conv-1)]
+        self.batch_norm_list.append(dg.BatchNorm(n_mels * outputs_per_step, 
+                            param_attr = fluid.ParamAttr(name='weight'), 
+                            bias_attr = fluid.ParamAttr(name='bias'),
+                            moving_mean_name =  'moving_mean',
+                            moving_variance_name = 'moving_var',
+                            data_layout='NCHW'))
+        for i, layer in enumerate(self.batch_norm_list):
+            self.add_sublayer("batch_norm_list_{}".format(i), layer)
+        
+
+    def forward(self, input):
+        """
+        Post Conv Net.
+        
+        Args:
+            input (Variable): Shape(B, T, C), dtype: float32. The input value.
+        Returns:
+            output (Variable), Shape(B, T, C), the result after postconvnet.
+        """
+        input = layers.transpose(input, [0,2,1])
+        len = input.shape[-1]
+        for batch_norm, conv in zip(self.batch_norm_list, self.conv_list):
+            input = layers.dropout(layers.tanh(batch_norm(conv(input)[:,:,:len])), self.dropout)
+        output = layers.transpose(input, [0,2,1])
+        return output
\ No newline at end of file
diff --git a/parakeet/modules/prenet.py b/parakeet/modules/prenet.py
new file mode 100644
index 0000000..4ea50e1
--- /dev/null
+++ b/parakeet/modules/prenet.py
@@ -0,0 +1,31 @@
+import paddle.fluid.dygraph as dg
+import paddle.fluid.layers as layers
+
+class PreNet(dg.Layer):
+    def __init__(self, input_size, hidden_size, output_size, dropout_rate=0.2):
+        """
+        :param input_size: dimension of input
+        :param hidden_size: dimension of hidden unit
+        :param output_size: dimension of output
+        """
+        super(PreNet, self).__init__()
+        self.input_size = input_size
+        self.hidden_size = hidden_size
+        self.output_size = output_size
+        self.dropout_rate = dropout_rate
+        
+        self.linear1 = dg.Linear(input_size, hidden_size)
+        self.linear2 = dg.Linear(hidden_size, output_size)
+
+    def forward(self, x):
+        """
+        Pre Net before passing through the network.
+        
+        Args:
+            x (Variable): Shape(B, T, C), dtype: float32. The input value.
+        Returns:
+            x (Variable), Shape(B, T, C), the result after pernet.
+        """
+        x = layers.dropout(layers.relu(self.linear1(x)), self.dropout_rate)
+        x = layers.dropout(layers.relu(self.linear2(x)), self.dropout_rate)
+        return x
diff --git a/parakeet/modules/utils.py b/parakeet/modules/utils.py
new file mode 100644
index 0000000..626d5f2
--- /dev/null
+++ b/parakeet/modules/utils.py
@@ -0,0 +1,73 @@
+import numpy as np
+import librosa
+import os, copy
+from scipy import signal
+import paddle.fluid.layers as layers
+
+
+def get_positional_table(d_pos_vec, n_position=1024):
+    position_enc = np.array([
+        [pos / np.power(10000, 2*i/d_pos_vec) for i in range(d_pos_vec)]
+        if pos != 0 else np.zeros(d_pos_vec) for pos in range(n_position)])
+
+    position_enc[1:, 0::2] = np.sin(position_enc[1:, 0::2]) # dim 2i
+    position_enc[1:, 1::2] = np.cos(position_enc[1:, 1::2]) # dim 2i+1
+    return position_enc
+
+def get_sinusoid_encoding_table(n_position, d_hid, padding_idx=None):
+    ''' Sinusoid position encoding table '''
+
+    def cal_angle(position, hid_idx):
+        return position / np.power(10000, 2 * (hid_idx // 2) / d_hid)
+
+    def get_posi_angle_vec(position):
+        return [cal_angle(position, hid_j) for hid_j in range(d_hid)]
+
+    sinusoid_table = np.array([get_posi_angle_vec(pos_i) for pos_i in range(n_position)])
+
+    sinusoid_table[:, 0::2] = np.sin(sinusoid_table[:, 0::2])  # dim 2i
+    sinusoid_table[:, 1::2] = np.cos(sinusoid_table[:, 1::2])  # dim 2i+1
+
+    if padding_idx is not None:
+        # zero vector for padding dimension
+        sinusoid_table[padding_idx] = 0.
+
+    return sinusoid_table
+
+def get_non_pad_mask(seq):
+    return layers.unsqueeze((seq != 0).astype(np.float32),[-1])
+
+def get_attn_key_pad_mask(seq_k, seq_q):
+    ''' For masking out the padding part of key sequence. '''
+
+    # Expand to fit the shape of key query attention matrix.
+    len_q = seq_q.shape[1]
+    padding_mask = (seq_k != 0).astype(np.float32)
+    padding_mask = layers.expand(layers.unsqueeze(padding_mask,[1]), [1, len_q, 1]) 
+    return padding_mask
+
+def get_triu_tensor(seq_k, seq_q):
+    ''' For make a triu tensor '''
+    len_k = seq_k.shape[1]
+    len_q = seq_q.shape[1]
+    batch_size = seq_k.shape[0]
+    triu_tensor = np.triu(np.ones([len_k, len_q]), 1)
+    triu_tensor = np.repeat(np.expand_dims(triu_tensor, axis=0) ,batch_size, axis=0)
+    
+    return triu_tensor
+
+def guided_attention(N, T, g=0.2):
+    '''Guided attention. Refer to page 3 on the paper.'''
+    W = np.zeros((N, T), dtype=np.float32)
+    for n_pos in range(W.shape[0]):
+        for t_pos in range(W.shape[1]):
+            W[n_pos, t_pos] = 1 - np.exp(-(t_pos / float(T) - n_pos / float(N)) ** 2 / (2 * g * g))
+    return W
+
+
+def cross_entropy(input, label, position_weight=5.0, epsilon=0.0001):
+    input = -1 * label * layers.log(input + epsilon) - (1-label) * layers.log(1 - input + epsilon)
+    label = input * (label * (position_weight - 1) + 1)
+    return layers.reduce_sum(label, dim=[0, 1])
+        
+
diff --git a/tests/test_ljspeech.py b/tests/test_ljspeech.py
index 04db6a9..34f5011 100644
--- a/tests/test_ljspeech.py
+++ b/tests/test_ljspeech.py
@@ -7,4 +7,4 @@ LJSPEECH_ROOT = Path("/workspace/datasets/LJSpeech-1.1")
 ljspeech = LJSpeech(LJSPEECH_ROOT)
 ljspeech_cargo = DataCargo(ljspeech, batch_size=16, shuffle=True)
 for i, batch in enumerate(ljspeech_cargo):
-    print(i)
\ No newline at end of file
+    print(i)