Files
WhisperLiveKit/whisperlivekit/diarization/sortformer_backend.py

467 lines
20 KiB
Python

import numpy as np
import torch
import logging
import threading
import time
import wave
from typing import List, Optional
from queue import SimpleQueue, Empty
from whisperlivekit.timed_objects import SpeakerSegment
logger = logging.getLogger(__name__)
try:
from nemo.collections.asr.models import SortformerEncLabelModel
from nemo.collections.asr.modules import AudioToMelSpectrogramPreprocessor
except ImportError:
raise SystemExit("""Please use `pip install "git+https://github.com/NVIDIA/NeMo.git@main#egg=nemo_toolkit[asr]"` to use the Sortformer diarization""")
class StreamingSortformerState:
"""
This class creates a class instance that will be used to store the state of the
streaming Sortformer model.
Attributes:
spkcache (torch.Tensor): Speaker cache to store embeddings from start
spkcache_lengths (torch.Tensor): Lengths of the speaker cache
spkcache_preds (torch.Tensor): The speaker predictions for the speaker cache parts
fifo (torch.Tensor): FIFO queue to save the embedding from the latest chunks
fifo_lengths (torch.Tensor): Lengths of the FIFO queue
fifo_preds (torch.Tensor): The speaker predictions for the FIFO queue parts
spk_perm (torch.Tensor): Speaker permutation information for the speaker cache
mean_sil_emb (torch.Tensor): Mean silence embedding
n_sil_frames (torch.Tensor): Number of silence frames
"""
def __init__(self):
self.spkcache = None # Speaker cache to store embeddings from start
self.spkcache_lengths = None
self.spkcache_preds = None # speaker cache predictions
self.fifo = None # to save the embedding from the latest chunks
self.fifo_lengths = None
self.fifo_preds = None
self.spk_perm = None
self.mean_sil_emb = None
self.n_sil_frames = None
class SortformerDiarization:
def __init__(self, model_name: str = "nvidia/diar_streaming_sortformer_4spk-v2"):
"""
Stores the shared streaming Sortformer diarization model. Used when a new online_diarization is initialized.
"""
self._load_model(model_name)
def _load_model(self, model_name: str):
"""Load and configure the Sortformer model for streaming."""
try:
self.diar_model = SortformerEncLabelModel.from_pretrained(model_name)
self.diar_model.eval()
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
self.diar_model.to(device)
## to test
# for name, param in self.diar_model.named_parameters():
# if param.device != device:
# raise RuntimeError(f"Parameter {name} is on {param.device} but should be on {device}")
logger.info(f"Using {device.type.upper()} for Sortformer model")
self.diar_model.sortformer_modules.chunk_len = 10
self.diar_model.sortformer_modules.subsampling_factor = 10
self.diar_model.sortformer_modules.chunk_right_context = 0
self.diar_model.sortformer_modules.chunk_left_context = 10
self.diar_model.sortformer_modules.spkcache_len = 188
self.diar_model.sortformer_modules.fifo_len = 188
self.diar_model.sortformer_modules.spkcache_update_period = 144
self.diar_model.sortformer_modules.log = False
self.diar_model.sortformer_modules._check_streaming_parameters()
except Exception as e:
logger.error(f"Failed to load Sortformer model: {e}")
raise
class SortformerDiarizationOnline:
def __init__(self, shared_model, sample_rate: int = 16000):
"""
Initialize the streaming Sortformer diarization system.
Args:
sample_rate: Audio sample rate (default: 16000)
model_name: Pre-trained model name (default: "nvidia/diar_streaming_sortformer_4spk-v2")
"""
self.sample_rate = sample_rate
self.speaker_segments = []
self.buffer_audio = np.array([], dtype=np.float32)
self.segment_lock = threading.Lock()
self.global_time_offset = 0.0
self.processed_time = 0.0
self.debug = False
self.diar_model = shared_model.diar_model
self.audio2mel = AudioToMelSpectrogramPreprocessor(
window_size=0.025,
normalize="NA",
n_fft=512,
features=128,
pad_to=0
)
self.audio2mel.to(self.diar_model.device)
self.chunk_duration_seconds = (
self.diar_model.sortformer_modules.chunk_len *
self.diar_model.sortformer_modules.subsampling_factor *
self.diar_model.preprocessor._cfg.window_stride
)
self._init_streaming_state()
self._previous_chunk_features = None
self._chunk_index = 0
self._len_prediction = None
# Audio buffer to store PCM chunks for debugging
self.audio_buffer = []
# Buffer for accumulating audio chunks until reaching chunk_duration_seconds
self.audio_chunk_buffer = []
self.accumulated_duration = 0.0
logger.info("SortformerDiarization initialized successfully")
def _init_streaming_state(self):
"""Initialize the streaming state for the model."""
batch_size = 1
device = self.diar_model.device
self.streaming_state = StreamingSortformerState()
self.streaming_state.spkcache = torch.zeros(
(batch_size, self.diar_model.sortformer_modules.spkcache_len, self.diar_model.sortformer_modules.fc_d_model),
device=device
)
self.streaming_state.spkcache_preds = torch.zeros(
(batch_size, self.diar_model.sortformer_modules.spkcache_len, self.diar_model.sortformer_modules.n_spk),
device=device
)
self.streaming_state.spkcache_lengths = torch.zeros((batch_size,), dtype=torch.long, device=device)
self.streaming_state.fifo = torch.zeros(
(batch_size, self.diar_model.sortformer_modules.fifo_len, self.diar_model.sortformer_modules.fc_d_model),
device=device
)
self.streaming_state.fifo_lengths = torch.zeros((batch_size,), dtype=torch.long, device=device)
self.streaming_state.mean_sil_emb = torch.zeros((batch_size, self.diar_model.sortformer_modules.fc_d_model), device=device)
self.streaming_state.n_sil_frames = torch.zeros((batch_size,), dtype=torch.long, device=device)
# Initialize total predictions tensor
self.total_preds = torch.zeros((batch_size, 0, self.diar_model.sortformer_modules.n_spk), device=device)
def insert_silence(self, silence_duration: Optional[float]):
"""
Insert silence period by adjusting the global time offset.
Args:
silence_duration: Duration of silence in seconds
"""
with self.segment_lock:
self.global_time_offset += silence_duration
logger.debug(f"Inserted silence of {silence_duration:.2f}s, new offset: {self.global_time_offset:.2f}s")
async def diarize(self, pcm_array: np.ndarray):
"""
Process audio data for diarization in streaming fashion.
Args:
pcm_array: Audio data as numpy array
"""
try:
if self.debug:
self.audio_buffer.append(pcm_array.copy())
threshold = int(self.chunk_duration_seconds * self.sample_rate)
self.buffer_audio = np.concatenate([self.buffer_audio, pcm_array.copy()])
if not len(self.buffer_audio) >= threshold:
return
audio = self.buffer_audio[:threshold]
self.buffer_audio = self.buffer_audio[threshold:]
device = self.diar_model.device
audio_signal_chunk = torch.tensor(audio, device=device).unsqueeze(0)
audio_signal_length_chunk = torch.tensor([audio_signal_chunk.shape[1]], device=device)
processed_signal_chunk, processed_signal_length_chunk = self.audio2mel.get_features(
audio_signal_chunk, audio_signal_length_chunk
)
processed_signal_chunk = processed_signal_chunk.to(device)
processed_signal_length_chunk = processed_signal_length_chunk.to(device)
if self._previous_chunk_features is not None:
to_add = self._previous_chunk_features[:, :, -99:].to(device)
total_features = torch.concat([to_add, processed_signal_chunk], dim=2).to(device)
else:
total_features = processed_signal_chunk.to(device)
self._previous_chunk_features = processed_signal_chunk.to(device)
chunk_feat_seq_t = torch.transpose(total_features, 1, 2).to(device)
with torch.inference_mode():
left_offset = 8 if self._chunk_index > 0 else 0
right_offset = 8
self.streaming_state, self.total_preds = self.diar_model.forward_streaming_step(
processed_signal=chunk_feat_seq_t,
processed_signal_length=torch.tensor([chunk_feat_seq_t.shape[1]]).to(device),
streaming_state=self.streaming_state,
total_preds=self.total_preds,
left_offset=left_offset,
right_offset=right_offset,
)
# Convert predictions to speaker segments
self._process_predictions()
self._chunk_index += 1
except Exception as e:
logger.error(f"Error in diarize: {e}")
raise
# TODO: Handle case when stream ends with partial buffer (accumulated_duration > 0 but < chunk_duration_seconds)
def _process_predictions(self):
"""Process model predictions and convert to speaker segments."""
try:
preds_np = self.total_preds[0].cpu().numpy()
active_speakers = np.argmax(preds_np, axis=1)
if self._len_prediction is None:
self._len_prediction = len(active_speakers)
# Get predictions for current chunk
frame_duration = self.chunk_duration_seconds / self._len_prediction
current_chunk_preds = active_speakers[-self._len_prediction:]
with self.segment_lock:
# Process predictions into segments
base_time = self._chunk_index * self.chunk_duration_seconds + self.global_time_offset
for idx, spk in enumerate(current_chunk_preds):
start_time = base_time + idx * frame_duration
end_time = base_time + (idx + 1) * frame_duration
# Check if this continues the last segment or starts a new one
if (self.speaker_segments and
self.speaker_segments[-1].speaker == spk and
abs(self.speaker_segments[-1].end - start_time) < frame_duration * 0.5):
# Continue existing segment
self.speaker_segments[-1].end = end_time
else:
# Create new segment
self.speaker_segments.append(SpeakerSegment(
speaker=spk,
start=start_time,
end=end_time
))
# Update processed time
self.processed_time = max(self.processed_time, base_time + self.chunk_duration_seconds)
logger.debug(f"Processed chunk {self._chunk_index}, total segments: {len(self.speaker_segments)}")
except Exception as e:
logger.error(f"Error processing predictions: {e}")
def assign_speakers_to_tokens(self, tokens: list, use_punctuation_split: bool = False) -> list:
"""
Assign speakers to tokens based on timing overlap with speaker segments.
Args:
tokens: List of tokens with timing information
use_punctuation_split: Whether to use punctuation for boundary refinement
Returns:
List of tokens with speaker assignments
Last speaker_segment
"""
with self.segment_lock:
segments = self.speaker_segments.copy()
if not segments or not tokens:
logger.debug("No segments or tokens available for speaker assignment")
return tokens
logger.debug(f"Assigning speakers to {len(tokens)} tokens using {len(segments)} segments")
use_punctuation_split = False
if not use_punctuation_split:
# Simple overlap-based assignment
for token in tokens:
token.speaker = -1 # Default to no speaker
for segment in segments:
# Check for timing overlap
if not (segment.end <= token.start or segment.start >= token.end):
token.speaker = segment.speaker + 1 # Convert to 1-based indexing
break
else:
# Use punctuation-aware assignment (similar to diart_backend)
tokens = self._add_speaker_to_tokens_with_punctuation(segments, tokens)
return tokens
def _add_speaker_to_tokens_with_punctuation(self, segments: List[SpeakerSegment], tokens: list) -> list:
"""
Assign speakers to tokens with punctuation-aware boundary adjustment.
Args:
segments: List of speaker segments
tokens: List of tokens to assign speakers to
Returns:
List of tokens with speaker assignments
"""
punctuation_marks = {'.', '!', '?'}
punctuation_tokens = [token for token in tokens if token.text.strip() in punctuation_marks]
# Convert segments to concatenated format
segments_concatenated = self._concatenate_speakers(segments)
# Adjust segment boundaries based on punctuation
for ind, segment in enumerate(segments_concatenated):
for i, punctuation_token in enumerate(punctuation_tokens):
if punctuation_token.start > segment['end']:
after_length = punctuation_token.start - segment['end']
before_length = segment['end'] - punctuation_tokens[i - 1].end if i > 0 else float('inf')
if before_length > after_length:
segment['end'] = punctuation_token.start
if i < len(punctuation_tokens) - 1 and ind + 1 < len(segments_concatenated):
segments_concatenated[ind + 1]['begin'] = punctuation_token.start
else:
segment['end'] = punctuation_tokens[i - 1].end if i > 0 else segment['end']
if i < len(punctuation_tokens) - 1 and ind - 1 >= 0:
segments_concatenated[ind - 1]['begin'] = punctuation_tokens[i - 1].end
break
# Ensure non-overlapping tokens
last_end = 0.0
for token in tokens:
start = max(last_end + 0.01, token.start)
token.start = start
token.end = max(start, token.end)
last_end = token.end
# Assign speakers based on adjusted segments
ind_last_speaker = 0
for segment in segments_concatenated:
for i, token in enumerate(tokens[ind_last_speaker:]):
if token.end <= segment['end']:
token.speaker = segment['speaker']
ind_last_speaker = i + 1
elif token.start > segment['end']:
break
return tokens
def _concatenate_speakers(self, segments: List[SpeakerSegment]) -> List[dict]:
"""
Concatenate consecutive segments from the same speaker.
Args:
segments: List of speaker segments
Returns:
List of concatenated speaker segments
"""
if not segments:
return []
segments_concatenated = [{"speaker": segments[0].speaker + 1, "begin": segments[0].start, "end": segments[0].end}]
for segment in segments[1:]:
speaker = segment.speaker + 1
if segments_concatenated[-1]['speaker'] != speaker:
segments_concatenated.append({"speaker": speaker, "begin": segment.start, "end": segment.end})
else:
segments_concatenated[-1]['end'] = segment.end
return segments_concatenated
def get_segments(self) -> List[SpeakerSegment]:
"""Get a copy of the current speaker segments."""
with self.segment_lock:
return self.speaker_segments.copy()
def clear_old_segments(self, older_than: float = 30.0):
"""Clear segments older than the specified time."""
with self.segment_lock:
current_time = self.processed_time
self.speaker_segments = [
segment for segment in self.speaker_segments
if current_time - segment.end < older_than
]
logger.debug(f"Cleared old segments, remaining: {len(self.speaker_segments)}")
def close(self):
"""Close the diarization system and clean up resources."""
logger.info("Closing SortformerDiarization")
with self.segment_lock:
self.speaker_segments.clear()
if self.debug:
concatenated_audio = np.concatenate(self.audio_buffer)
audio_data_int16 = (concatenated_audio * 32767).astype(np.int16)
with wave.open("diarization_audio.wav", "wb") as wav_file:
wav_file.setnchannels(1) # mono audio
wav_file.setsampwidth(2) # 2 bytes per sample (int16)
wav_file.setframerate(self.sample_rate)
wav_file.writeframes(audio_data_int16.tobytes())
logger.info(f"Saved {len(concatenated_audio)} samples to diarization_audio.wav")
def extract_number(s: str) -> int:
"""Extract number from speaker string (compatibility function)."""
import re
m = re.search(r'\d+', s)
return int(m.group()) if m else 0
if __name__ == '__main__':
import asyncio
import librosa
async def main():
"""TEST ONLY."""
an4_audio = 'audio_test.mp3'
signal, sr = librosa.load(an4_audio, sr=16000)
signal = signal[:16000*30]
print("\n" + "=" * 50)
print("ground truth:")
print("Speaker 0: 0:00 - 0:09")
print("Speaker 1: 0:09 - 0:19")
print("Speaker 2: 0:19 - 0:25")
print("Speaker 0: 0:25 - 0:30")
print("=" * 50)
diarization = SortformerDiarization(sample_rate=16000)
chunk_size = 1600
for i in range(0, len(signal), chunk_size):
chunk = signal[i:i+chunk_size]
await diarization.diarize(chunk)
print(f"Processed chunk {i // chunk_size + 1}")
segments = diarization.get_segments()
print("\nDiarization results:")
for segment in segments:
print(f"Speaker {segment.speaker}: {segment.start:.2f}s - {segment.end:.2f}s")
asyncio.run(main())