inference truncated NEED TO BE TESTED

layers/tacotron2.py

@@ -202,6 +202,7 @@ class Encoder(nn.Module):
             num_layers=1,
             batch_first=True,
             bidirectional=True)
+        self.rnn_state = None
 
     def forward(self, x, input_lengths):
         x = self.convolutions(x)
@@ -224,6 +225,16 @@ class Encoder(nn.Module):
         outputs, _ = self.lstm(x)
         return outputs
 
+    def inference_truncated(self, x):
+        """
+        Preserve encoder state for continuous inference
+        """
+        x = self.convolutions(x)
+        x = x.transpose(1, 2)
+        self.lstm.flatten_parameters()
+        outputs, self.rnn_state = self.lstm(x, self.rnn_state)
+        return outputs
+
 # adapted from https://github.com/NVIDIA/tacotron2/
 class Decoder(nn.Module):
     def __init__(self, in_features, inputs_dim, r, attn_win):
@@ -264,31 +275,34 @@ class Decoder(nn.Module):
         self.attention_rnn_init = nn.Embedding(1, self.attention_rnn_dim)
         self.go_frame_init = nn.Embedding(1, self.mel_channels * r)
         self.decoder_rnn_inits = nn.Embedding(1, self.decoder_rnn_dim)
+        self.memory_truncated = None
 
     def get_go_frame(self, inputs):
         B = inputs.size(0)
         memory = self.go_frame_init(inputs.data.new_zeros(B).long())
         return memory
 
-    def _init_states(self, inputs, mask):
+    def _init_states(self, inputs, mask, keep_states=False):
         B = inputs.size(0)
         T = inputs.size(1)
 
-        self.attention_hidden = self.attention_rnn_init(
+        if not keep_states:
-            inputs.data.new_zeros(B).long())
+            self.attention_hidden = self.attention_rnn_init(
-        self.attention_cell = Variable(
+                inputs.data.new_zeros(B).long())
-            inputs.data.new(B, self.attention_rnn_dim).zero_())
+            self.attention_cell = Variable(
+                inputs.data.new(B, self.attention_rnn_dim).zero_())
 
-        self.decoder_hidden = self.decoder_rnn_inits(
+            self.decoder_hidden = self.decoder_rnn_inits(
-            inputs.data.new_zeros(B).long())
+                inputs.data.new_zeros(B).long())
-        self.decoder_cell = Variable(
+            self.decoder_cell = Variable(
-            inputs.data.new(B, self.decoder_rnn_dim).zero_())
+                inputs.data.new(B, self.decoder_rnn_dim).zero_())
+            
+            self.context = Variable(
+            inputs.data.new(B, self.encoder_embedding_dim).zero_())
 
         self.attention_weights = Variable(inputs.data.new(B, T).zero_())
         self.attention_weights_cum = Variable(inputs.data.new(B, T).zero_())
-        self.context = Variable(
+        
-            inputs.data.new(B, self.encoder_embedding_dim).zero_())
-
         self.inputs = inputs
         self.processed_inputs = self.attention_layer.inputs_layer(inputs)
         self.mask = mask
@@ -399,6 +413,44 @@ class Decoder(nn.Module):
 
         return outputs, gate_outputs, alignments
 
+    def inference_truncated(self, inputs):
+        """
+        Preserve decoder states for continuous inference
+        """
+        if self.memory_truncated is None:
+            self.memory_truncated = self.get_go_frame(inputs)
+            self._init_states(inputs, mask=None, keep_states=False)
+        else:
+            self._init_states(inputs, mask=None, keep_states=True)
+
+        self.attention_layer.init_win_idx()
+        outputs, gate_outputs, alignments, t = [], [], [], 0
+        stop_flags = [False, False]
+        while True:
+            memory = self.prenet(self.memory_truncated)
+            mel_output, gate_output, alignment = self.decode(memory)
+            gate_output = torch.sigmoid(gate_output.data)
+            outputs += [mel_output.squeeze(1)]
+            gate_outputs += [gate_output]
+            alignments += [alignment]
+
+            stop_flags[0] = stop_flags[0] or gate_output > 0.5
+            stop_flags[1] = stop_flags[1] or alignment[0, -2:].sum() > 0.5
+            if all(stop_flags):
+                break
+            elif len(outputs) == self.max_decoder_steps:
+                print("   | > Decoder stopped with 'max_decoder_steps")
+                break
+
+            self.memory_truncated = mel_output
+            t += 1
+
+        outputs, gate_outputs, alignments = self._parse_outputs(
+            outputs, gate_outputs, alignments)
+
+        return outputs, gate_outputs, alignments
+
+
     def inference_step(self, inputs, t, memory=None):
         """
         For debug purposes

models/tacotron2.py

@@ -46,6 +46,20 @@ class Tacotron2(nn.Module):
             encoder_outputs)
         mel_outputs_postnet = self.postnet(mel_outputs)
         mel_outputs_postnet = mel_outputs + mel_outputs_postnet
+        mel_outputs, mel_outputs_postnet, alignments = self.shape_outputs(
+            mel_outputs, mel_outputs_postnet, alignments)
+        return mel_outputs, mel_outputs_postnet, alignments, stop_tokens
+
+
+    def inference_truncated(self, text):
+        """
+        Preserve model states for continuous inference
+        """
+        embedded_inputs = self.embedding(text).transpose(1, 2)
+        encoder_outputs = self.encoder.inference_truncated(embedded_inputs)
+        mel_outputs, stop_tokens, alignments = self.decoder.inference_truncated(encoder_outputs)
+        mel_outputs_postnet = self.postnet(mel_outputs)
+        mel_outputs_postnet = mel_outputs + mel_outputs_postnet
         mel_outputs, mel_outputs_postnet, alignments = self.shape_outputs(
             mel_outputs, mel_outputs_postnet, alignments)
         return mel_outputs, mel_outputs_postnet, alignments, stop_tokens

utils/synthesis.py

@@ -8,19 +8,35 @@ from .visual import visualize
 from matplotlib import pylab as plt
 
 
-def synthesis(m, s, CONFIG, use_cuda, ap):
+def synthesis(model, text, CONFIG, use_cuda, ap, truncated=False):
+    """Synthesize voice for the given text.
+
+        Args:
+            model (TTS.models): model to synthesize.
+            text (str): target text
+            CONFIG (dict): config dictionary to be loaded from config.json.
+            use_cuda (bool): enable cuda.
+            ap (TTS.utils.audio.AudioProcessor): audio processor to process
+                model outputs.
+            truncated (bool): keep model states after inference. It can be used
+                for continuous inference at long texts.
+    """
     text_cleaner = [CONFIG.text_cleaner]
     if CONFIG.use_phonemes:
         seq = np.asarray(
-            phoneme_to_sequence(s, text_cleaner, CONFIG.phoneme_language),
+            phoneme_to_sequence(text, text_cleaner, CONFIG.phoneme_language),
             dtype=np.int32)
     else:
-        seq = np.asarray(text_to_sequence(s, text_cleaner), dtype=np.int32)
+        seq = np.asarray(text_to_sequence(text, text_cleaner), dtype=np.int32)
     chars_var = torch.from_numpy(seq).unsqueeze(0)
     if use_cuda:
         chars_var = chars_var.cuda()
-    decoder_output, postnet_output, alignments, stop_tokens = m.inference(
+    if truncated:
-        chars_var.long())
+        decoder_output, postnet_output, alignments, stop_tokens = model.inference_truncated(
+            chars_var.long())
+    else:
+        decoder_output, postnet_output, alignments, stop_tokens = model.inference(
+            chars_var.long())
     postnet_output = postnet_output[0].data.cpu().numpy()
     decoder_output = decoder_output[0].data.cpu().numpy()
     alignment = alignments[0].cpu().data.numpy()