Upgrade to Silero-Vad V5 (#884)

* Fix window_size_samples to 512

* Update SileroVADModel

* Replace ONNX file with V5 version

faster_whisper/vad.py

@@ -1,7 +1,6 @@
 import bisect
 import functools
 import os
-import warnings
 
 from typing import List, NamedTuple, Optional
 
@@ -25,9 +24,6 @@ class VadOptions(NamedTuple):
         split aggressively just before max_speech_duration_s.
       min_silence_duration_ms: In the end of each speech chunk wait for min_silence_duration_ms
         before separating it
-      window_size_samples: Audio chunks of window_size_samples size are fed to the silero VAD model.
-        WARNING! Silero VAD models were trained using 512, 1024, 1536 samples for 16000 sample rate.
-        Values other than these may affect model performance!!
       speech_pad_ms: Final speech chunks are padded by speech_pad_ms each side
     """
 
@@ -35,7 +31,6 @@ class VadOptions(NamedTuple):
     min_speech_duration_ms: int = 250
     max_speech_duration_s: float = float("inf")
     min_silence_duration_ms: int = 2000
-    window_size_samples: int = 1024
     speech_pad_ms: int = 400
 
 
@@ -61,15 +56,8 @@ def get_speech_timestamps(
     min_speech_duration_ms = vad_options.min_speech_duration_ms
     max_speech_duration_s = vad_options.max_speech_duration_s
     min_silence_duration_ms = vad_options.min_silence_duration_ms
-    window_size_samples = vad_options.window_size_samples
+    window_size_samples = 512
     speech_pad_ms = vad_options.speech_pad_ms
-
-    if window_size_samples not in [512, 1024, 1536]:
-        warnings.warn(
-            "Unusual window_size_samples! Supported window_size_samples:\n"
-            " - [512, 1024, 1536] for 16000 sampling_rate"
-        )
-
     sampling_rate = 16000
     min_speech_samples = sampling_rate * min_speech_duration_ms / 1000
     speech_pad_samples = sampling_rate * speech_pad_ms / 1000
@@ -84,14 +72,14 @@ def get_speech_timestamps(
     audio_length_samples = len(audio)
 
     model = get_vad_model()
-    state = model.get_initial_state(batch_size=1)
+    state, context = model.get_initial_states(batch_size=1)
 
     speech_probs = []
     for current_start_sample in range(0, audio_length_samples, window_size_samples):
         chunk = audio[current_start_sample : current_start_sample + window_size_samples]
         if len(chunk) < window_size_samples:
             chunk = np.pad(chunk, (0, int(window_size_samples - len(chunk))))
-        speech_prob, state = model(chunk, state, sampling_rate)
+        speech_prob, state, context = model(chunk, state, context, sampling_rate)
         speech_probs.append(speech_prob)
 
     triggered = False
@@ -261,12 +249,12 @@ class SileroVADModel:
             sess_options=opts,
         )
 
-    def get_initial_state(self, batch_size: int):
-        h = np.zeros((2, batch_size, 64), dtype=np.float32)
-        c = np.zeros((2, batch_size, 64), dtype=np.float32)
-        return h, c
+    def get_initial_states(self, batch_size: int):
+        state = np.zeros((2, batch_size, 128), dtype=np.float32)
+        context = np.zeros((batch_size, 64), dtype=np.float32)
+        return state, context
 
-    def __call__(self, x, state, sr: int):
+    def __call__(self, x, state, context, sr: int):
         if len(x.shape) == 1:
             x = np.expand_dims(x, 0)
         if len(x.shape) > 2:
@@ -276,16 +264,15 @@ class SileroVADModel:
         if sr / x.shape[1] > 31.25:
             raise ValueError("Input audio chunk is too short")
 
-        h, c = state
+        x = np.concatenate([context, x], axis=1)
 
         ort_inputs = {
             "input": x,
-            "h": h,
-            "c": c,
+            "state": state,
             "sr": np.array(sr, dtype="int64"),
         }
 
-        out, h, c = self.session.run(None, ort_inputs)
-        state = (h, c)
+        out, state = self.session.run(None, ort_inputs)
+        context = x[..., -64:]
 
-        return out, state
+        return out, state, context