Fix all-zero duration case for GlowTTS

TTS/tts/models/glow_tts.py

@@ -310,7 +310,7 @@ class GlowTTS(BaseTTS):
         o_mean, o_log_scale, o_dur_log, x_mask = self.encoder(x, x_lengths, g=g)
         # compute output durations
         w = (torch.exp(o_dur_log) - 1) * x_mask * self.length_scale
-        w_ceil = torch.ceil(w)
+        w_ceil = torch.clamp_min(torch.ceil(w), 1)
         y_lengths = torch.clamp_min(torch.sum(w_ceil, [1, 2]), 1).long()
         y_max_length = None
         # compute masks

tests/tts_tests/test_glow_tts_train.py

@@ -10,7 +10,7 @@ output_path = os.path.join(get_tests_output_path(), "train_outputs")
 
 
 config = GlowTTSConfig(
-    batch_size=8,
+    batch_size=2,
     eval_batch_size=8,
     num_loader_workers=0,
     num_eval_loader_workers=0,
@@ -27,6 +27,7 @@ config = GlowTTSConfig(
     test_sentences=[
         "Be a voice, not an echo.",
     ],
+    data_dep_init_steps=1.0,
 )
 config.audio.do_trim_silence = True
 config.audio.trim_db = 60