Files
reflector/server/reflector/processors/audio_chunker_silero.py
Mathieu Virbel 9265d201b5 fix: restore previous behavior on live pipeline + audio downscaler (#561)
This commit restore the original behavior with frame cutting. While
silero is used on our gpu for files, look like it's not working great on
the live pipeline. To be investigated, but at the moment, what we keep
is:

- refactored to extract the downscale for further processing in the
pipeline
- remove any downscale implementation from audio_chunker and audio_merge
- removed batching from audio_merge too for now
2025-08-22 10:49:26 -06:00

299 lines
11 KiB
Python

from typing import Optional
import av
import numpy as np
import torch
from silero_vad import VADIterator, load_silero_vad
from reflector.processors.audio_chunker import AudioChunkerProcessor
from reflector.processors.audio_chunker_auto import AudioChunkerAutoProcessor
class AudioChunkerSileroProcessor(AudioChunkerProcessor):
"""
Assemble audio frames into chunks with VAD-based speech detection using Silero VAD
"""
def __init__(
self,
block_frames=256,
max_frames=1024,
use_onnx=True,
min_frames=2,
**kwargs,
):
super().__init__(**kwargs)
self.block_frames = block_frames
self.max_frames = max_frames
self.min_frames = min_frames
# Initialize Silero VAD
self._init_vad(use_onnx)
def _init_vad(self, use_onnx=False):
"""Initialize Silero VAD model"""
try:
torch.set_num_threads(1)
self.vad_model = load_silero_vad(onnx=use_onnx)
self.vad_iterator = VADIterator(self.vad_model, sampling_rate=16000)
self.logger.info("Silero VAD initialized successfully")
except Exception as e:
self.logger.error(f"Failed to initialize Silero VAD: {e}")
self.vad_model = None
self.vad_iterator = None
async def _chunk(self, data: av.AudioFrame) -> Optional[list[av.AudioFrame]]:
"""Process audio frame and return chunk when ready"""
self.frames.append(data)
# Check for speech segments every 32 frames (~1 second)
if len(self.frames) >= 32 and len(self.frames) % 32 == 0:
return await self._process_block()
# Safety fallback - emit if we hit max frames
elif len(self.frames) >= self.max_frames:
self.logger.warning(
f"AudioChunkerSileroProcessor: Reached max frames ({self.max_frames}), "
f"emitting first {self.max_frames // 2} frames"
)
frames_to_emit = self.frames[: self.max_frames // 2]
self.frames = self.frames[self.max_frames // 2 :]
if len(frames_to_emit) >= self.min_frames:
return frames_to_emit
else:
self.logger.debug(
f"Ignoring fallback segment with {len(frames_to_emit)} frames "
f"(< {self.min_frames} minimum)"
)
return None
async def _process_block(self) -> Optional[list[av.AudioFrame]]:
# Need at least 32 frames for VAD detection (~1 second)
if len(self.frames) < 32 or self.vad_iterator is None:
return None
# Processing block with current buffer size
print(f"Processing block: {len(self.frames)} frames in buffer")
try:
# Convert frames to numpy array for VAD
audio_array = self._frames_to_numpy(self.frames)
if audio_array is None:
# Fallback: emit all frames if conversion failed
frames_to_emit = self.frames[:]
self.frames = []
if len(frames_to_emit) >= self.min_frames:
return frames_to_emit
else:
self.logger.debug(
f"Ignoring conversion-failed segment with {len(frames_to_emit)} frames "
f"(< {self.min_frames} minimum)"
)
return None
# Find complete speech segments in the buffer
speech_end_frame = self._find_speech_segment_end(audio_array)
if speech_end_frame is None or speech_end_frame <= 0:
# No speech found but buffer is getting large
if len(self.frames) > 512:
# Check if it's all silence and can be discarded
# No speech segment found, buffer at {len(self.frames)} frames
# Could emit silence or discard old frames here
# For now, keep first 256 frames and discard older silence
if len(self.frames) > 768:
self.logger.debug(
f"Discarding {len(self.frames) - 256} old frames (likely silence)"
)
self.frames = self.frames[-256:]
return None
# Calculate segment timing information
frames_to_emit = self.frames[:speech_end_frame]
# Get timing from av.AudioFrame
if frames_to_emit:
first_frame = frames_to_emit[0]
last_frame = frames_to_emit[-1]
sample_rate = first_frame.sample_rate
# Calculate duration
total_samples = sum(f.samples for f in frames_to_emit)
duration_seconds = total_samples / sample_rate if sample_rate > 0 else 0
# Get timestamps if available
start_time = (
first_frame.pts * first_frame.time_base if first_frame.pts else 0
)
end_time = (
last_frame.pts * last_frame.time_base if last_frame.pts else 0
)
# Convert to HH:MM:SS format for logging
def format_time(seconds):
if not seconds:
return "00:00:00"
total_seconds = int(float(seconds))
hours = total_seconds // 3600
minutes = (total_seconds % 3600) // 60
secs = total_seconds % 60
return f"{hours:02d}:{minutes:02d}:{secs:02d}"
start_formatted = format_time(start_time)
end_formatted = format_time(end_time)
# Keep remaining frames for next processing
remaining_after = len(self.frames) - speech_end_frame
# Single structured log line
self.logger.info(
"Speech segment found",
start=start_formatted,
end=end_formatted,
frames=speech_end_frame,
duration=round(duration_seconds, 2),
buffer_before=len(self.frames),
remaining=remaining_after,
)
# Keep remaining frames for next processing
self.frames = self.frames[speech_end_frame:]
# Filter out segments with too few frames
if len(frames_to_emit) >= self.min_frames:
return frames_to_emit
else:
self.logger.debug(
f"Ignoring segment with {len(frames_to_emit)} frames "
f"(< {self.min_frames} minimum)"
)
except Exception as e:
self.logger.error(f"Error in VAD processing: {e}")
# Fallback to simple chunking
if len(self.frames) >= self.block_frames:
frames_to_emit = self.frames[: self.block_frames]
self.frames = self.frames[self.block_frames :]
if len(frames_to_emit) >= self.min_frames:
return frames_to_emit
else:
self.logger.debug(
f"Ignoring exception-fallback segment with {len(frames_to_emit)} frames "
f"(< {self.min_frames} minimum)"
)
return None
def _frames_to_numpy(self, frames: list[av.AudioFrame]) -> Optional[np.ndarray]:
"""Convert av.AudioFrame list to numpy array for VAD processing"""
if not frames:
return None
try:
audio_data = []
for frame in frames:
frame_array = frame.to_ndarray()
if len(frame_array.shape) == 2:
frame_array = frame_array.flatten()
audio_data.append(frame_array)
if not audio_data:
return None
combined_audio = np.concatenate(audio_data)
# Ensure float32 format
if combined_audio.dtype == np.int16:
# Normalize int16 audio to float32 in range [-1.0, 1.0]
combined_audio = combined_audio.astype(np.float32) / 32768.0
elif combined_audio.dtype != np.float32:
combined_audio = combined_audio.astype(np.float32)
return combined_audio
except Exception as e:
self.logger.error(f"Error converting frames to numpy: {e}")
return None
def _find_speech_segment_end(self, audio_array: np.ndarray) -> Optional[int]:
"""Find complete speech segments and return frame index at segment end"""
if self.vad_iterator is None or len(audio_array) == 0:
return None
try:
# Process audio in 512-sample windows for VAD
window_size = 512
min_silence_windows = 3 # Require 3 windows of silence after speech
# Track speech state
in_speech = False
speech_start = None
speech_end = None
silence_count = 0
for i in range(0, len(audio_array), window_size):
chunk = audio_array[i : i + window_size]
if len(chunk) < window_size:
chunk = np.pad(chunk, (0, window_size - len(chunk)))
# Detect if this window has speech
speech_dict = self.vad_iterator(chunk, return_seconds=True)
# VADIterator returns dict with 'start' and 'end' when speech segments are detected
if speech_dict:
if not in_speech:
# Speech started
speech_start = i
in_speech = True
# Debug: print(f"Speech START at sample {i}, VAD: {speech_dict}")
silence_count = 0 # Reset silence counter
continue
if not in_speech:
continue
# We're in speech but found silence
silence_count += 1
if silence_count < min_silence_windows:
continue
# Found end of speech segment
speech_end = i - (min_silence_windows - 1) * window_size
# Debug: print(f"Speech END at sample {speech_end}")
# Convert sample position to frame index
samples_per_frame = self.frames[0].samples if self.frames else 1024
frame_index = speech_end // samples_per_frame
# Ensure we don't exceed buffer
frame_index = min(frame_index, len(self.frames))
return frame_index
return None
except Exception as e:
self.logger.error(f"Error finding speech segment: {e}")
return None
async def _flush(self):
frames = self.frames[:]
self.frames = []
if frames:
if len(frames) >= self.min_frames:
await self.emit(frames)
else:
self.logger.debug(
f"Ignoring flush segment with {len(frames)} frames "
f"(< {self.min_frames} minimum)"
)
AudioChunkerAutoProcessor.register("silero", AudioChunkerSileroProcessor)