aadnk's picture
Adding support for word timestamps
f55c594
from abc import ABC, abstractmethod
from collections import Counter, deque
import time
from typing import Any, Deque, Iterator, List, Dict
from pprint import pprint
from src.hooks.progressListener import ProgressListener
from src.hooks.subTaskProgressListener import SubTaskProgressListener
from src.hooks.whisperProgressHook import create_progress_listener_handle
from src.modelCache import GLOBAL_MODEL_CACHE, ModelCache
from src.segments import merge_timestamps
from src.whisper.abstractWhisperContainer import AbstractWhisperCallback
# Workaround for https://github.com/tensorflow/tensorflow/issues/48797
try:
import tensorflow as tf
except ModuleNotFoundError:
# Error handling
pass
import torch
import ffmpeg
import numpy as np
from src.utils import format_timestamp
from enum import Enum
class NonSpeechStrategy(Enum):
"""
Ignore non-speech frames segments.
"""
SKIP = 1
"""
Just treat non-speech segments as speech.
"""
CREATE_SEGMENT = 2
"""
Expand speech segments into subsequent non-speech segments.
"""
EXPAND_SEGMENT = 3
# Defaults for Silero
SPEECH_TRESHOLD = 0.3
# Minimum size of segments to process
MIN_SEGMENT_DURATION = 1
# The maximum time for texts from old segments to be used in the next segment
MAX_PROMPT_WINDOW = 0 # seconds (0 = disabled)
PROMPT_NO_SPEECH_PROB = 0.1 # Do not pass the text from segments with a no speech probability higher than this
VAD_MAX_PROCESSING_CHUNK = 60 * 60 # 60 minutes of audio
class TranscriptionConfig(ABC):
def __init__(self, non_speech_strategy: NonSpeechStrategy = NonSpeechStrategy.SKIP,
segment_padding_left: float = None, segment_padding_right = None, max_silent_period: float = None,
max_merge_size: float = None, max_prompt_window: float = None, initial_segment_index = -1):
self.non_speech_strategy = non_speech_strategy
self.segment_padding_left = segment_padding_left
self.segment_padding_right = segment_padding_right
self.max_silent_period = max_silent_period
self.max_merge_size = max_merge_size
self.max_prompt_window = max_prompt_window
self.initial_segment_index = initial_segment_index
class PeriodicTranscriptionConfig(TranscriptionConfig):
def __init__(self, periodic_duration: float, non_speech_strategy: NonSpeechStrategy = NonSpeechStrategy.SKIP,
segment_padding_left: float = None, segment_padding_right = None, max_silent_period: float = None,
max_merge_size: float = None, max_prompt_window: float = None, initial_segment_index = -1):
super().__init__(non_speech_strategy, segment_padding_left, segment_padding_right, max_silent_period, max_merge_size, max_prompt_window, initial_segment_index)
self.periodic_duration = periodic_duration
class AbstractTranscription(ABC):
def __init__(self, sampling_rate: int = 16000):
self.sampling_rate = sampling_rate
def get_audio_segment(self, str, start_time: str = None, duration: str = None):
return load_audio(str, self.sampling_rate, start_time, duration)
def is_transcribe_timestamps_fast(self):
"""
Determine if get_transcribe_timestamps is fast enough to not need parallelization.
"""
return False
@abstractmethod
def get_transcribe_timestamps(self, audio: str, config: TranscriptionConfig, start_time: float, end_time: float):
"""
Get the start and end timestamps of the sections that should be transcribed by this VAD method.
Parameters
----------
audio: str
The audio file.
config: TranscriptionConfig
The transcription configuration.
Returns
-------
A list of start and end timestamps, in fractional seconds.
"""
return
def get_merged_timestamps(self, timestamps: List[Dict[str, Any]], config: TranscriptionConfig, total_duration: float):
"""
Get the start and end timestamps of the sections that should be transcribed by this VAD method,
after merging the given segments using the specified configuration.
Parameters
----------
audio: str
The audio file.
config: TranscriptionConfig
The transcription configuration.
Returns
-------
A list of start and end timestamps, in fractional seconds.
"""
merged = merge_timestamps(timestamps, config.max_silent_period, config.max_merge_size,
config.segment_padding_left, config.segment_padding_right)
if config.non_speech_strategy != NonSpeechStrategy.SKIP:
# Expand segments to include the gaps between them
if (config.non_speech_strategy == NonSpeechStrategy.CREATE_SEGMENT):
# When we have a prompt window, we create speech segments betwen each segment if we exceed the merge size
merged = self.fill_gaps(merged, total_duration=total_duration, max_expand_size=config.max_merge_size)
elif config.non_speech_strategy == NonSpeechStrategy.EXPAND_SEGMENT:
# With no prompt window, it is better to just expand the segments (this effectively passes the prompt to the next segment)
merged = self.expand_gaps(merged, total_duration=total_duration)
else:
raise Exception("Unknown non-speech strategy: " + str(config.non_speech_strategy))
print("Transcribing non-speech:")
pprint(merged)
return merged
def transcribe(self, audio: str, whisperCallable: AbstractWhisperCallback, config: TranscriptionConfig,
progressListener: ProgressListener = None):
"""
Transcribe the given audo file.
Parameters
----------
audio: str
The audio file.
whisperCallable: WhisperCallback
A callback object to call to transcribe each segment.
Returns
-------
A list of start and end timestamps, in fractional seconds.
"""
try:
max_audio_duration = self.get_audio_duration(audio, config)
timestamp_segments = self.get_transcribe_timestamps(audio, config, 0, max_audio_duration)
# Get speech timestamps from full audio file
merged = self.get_merged_timestamps(timestamp_segments, config, max_audio_duration)
# A deque of transcribed segments that is passed to the next segment as a prompt
prompt_window = deque()
print("Processing timestamps:")
pprint(merged)
result = {
'text': "",
'segments': [],
'language': ""
}
languageCounter = Counter()
detected_language = None
segment_index = config.initial_segment_index
# Calculate progress
progress_start_offset = merged[0]['start'] if len(merged) > 0 else 0
progress_total_duration = sum([segment['end'] - segment['start'] for segment in merged])
# For each time segment, run whisper
for segment in merged:
segment_index += 1
segment_start = segment['start']
segment_end = segment['end']
segment_expand_amount = segment.get('expand_amount', 0)
segment_gap = segment.get('gap', False)
segment_duration = segment_end - segment_start
if segment_duration < MIN_SEGMENT_DURATION:
continue
# Audio to run on Whisper
segment_audio = self.get_audio_segment(audio, start_time = str(segment_start), duration = str(segment_duration))
# Previous segments to use as a prompt
segment_prompt = ' '.join([segment['text'] for segment in prompt_window]) if len(prompt_window) > 0 else None
# Detected language
detected_language = languageCounter.most_common(1)[0][0] if len(languageCounter) > 0 else None
print("Running whisper from ", format_timestamp(segment_start), " to ", format_timestamp(segment_end), ", duration: ",
segment_duration, "expanded: ", segment_expand_amount, "prompt: ", segment_prompt, "language: ", detected_language)
perf_start_time = time.perf_counter()
scaled_progress_listener = SubTaskProgressListener(progressListener, base_task_total=progress_total_duration,
sub_task_start=segment_start - progress_start_offset, sub_task_total=segment_duration)
segment_result = whisperCallable.invoke(segment_audio, segment_index, segment_prompt, detected_language, progress_listener=scaled_progress_listener)
perf_end_time = time.perf_counter()
print("Whisper took {} seconds".format(perf_end_time - perf_start_time))
adjusted_segments = self.adjust_timestamp(segment_result["segments"], adjust_seconds=segment_start, max_source_time=segment_duration)
# Propagate expand amount to the segments
if (segment_expand_amount > 0):
segment_without_expansion = segment_duration - segment_expand_amount
for adjusted_segment in adjusted_segments:
adjusted_segment_end = adjusted_segment['end']
# Add expand amount if the segment got expanded
if (adjusted_segment_end > segment_without_expansion):
adjusted_segment["expand_amount"] = adjusted_segment_end - segment_without_expansion
# Append to output
result['text'] += segment_result['text']
result['segments'].extend(adjusted_segments)
# Increment detected language
if not segment_gap:
languageCounter[segment_result['language']] += 1
# Update prompt window
self.__update_prompt_window(prompt_window, adjusted_segments, segment_end, segment_gap, config)
if detected_language is not None:
result['language'] = detected_language
finally:
# Notify progress listener that we are done
if progressListener is not None:
progressListener.on_finished()
return result
def get_audio_duration(self, audio: str, config: TranscriptionConfig):
return get_audio_duration(audio)
def __update_prompt_window(self, prompt_window: Deque, adjusted_segments: List, segment_end: float, segment_gap: bool, config: TranscriptionConfig):
if (config.max_prompt_window is not None and config.max_prompt_window > 0):
# Add segments to the current prompt window (unless it is a speech gap)
if not segment_gap:
for segment in adjusted_segments:
if segment.get('no_speech_prob', 0) <= PROMPT_NO_SPEECH_PROB:
prompt_window.append(segment)
while (len(prompt_window) > 0):
first_end_time = prompt_window[0].get('end', 0)
# Time expanded in the segments should be discounted from the prompt window
first_expand_time = prompt_window[0].get('expand_amount', 0)
if (first_end_time - first_expand_time < segment_end - config.max_prompt_window):
prompt_window.popleft()
else:
break
def include_gaps(self, segments: Iterator[dict], min_gap_length: float, total_duration: float):
result = []
last_end_time = 0
for segment in segments:
segment_start = float(segment['start'])
segment_end = float(segment['end'])
if (last_end_time != segment_start):
delta = segment_start - last_end_time
if (min_gap_length is None or delta >= min_gap_length):
result.append( { 'start': last_end_time, 'end': segment_start, 'gap': True } )
last_end_time = segment_end
result.append(segment)
# Also include total duration if specified
if (total_duration is not None and last_end_time < total_duration):
delta = total_duration - segment_start
if (min_gap_length is None or delta >= min_gap_length):
result.append( { 'start': last_end_time, 'end': total_duration, 'gap': True } )
return result
# Expand the end time of each segment to the start of the next segment
def expand_gaps(self, segments: List[Dict[str, Any]], total_duration: float):
result = []
if len(segments) == 0:
return result
# Add gap at the beginning if needed
if (segments[0]['start'] > 0):
result.append({ 'start': 0, 'end': segments[0]['start'], 'gap': True } )
for i in range(len(segments) - 1):
current_segment = segments[i]
next_segment = segments[i + 1]
delta = next_segment['start'] - current_segment['end']
# Expand if the gap actually exists
if (delta >= 0):
current_segment = current_segment.copy()
current_segment['expand_amount'] = delta
current_segment['end'] = next_segment['start']
result.append(current_segment)
# Add last segment
last_segment = segments[-1]
result.append(last_segment)
# Also include total duration if specified
if (total_duration is not None):
last_segment = result[-1]
if (last_segment['end'] < total_duration):
last_segment = last_segment.copy()
last_segment['end'] = total_duration
result[-1] = last_segment
return result
def fill_gaps(self, segments: List[Dict[str, Any]], total_duration: float, max_expand_size: float = None):
result = []
if len(segments) == 0:
return result
# Add gap at the beginning if needed
if (segments[0]['start'] > 0):
result.append({ 'start': 0, 'end': segments[0]['start'], 'gap': True } )
for i in range(len(segments) - 1):
expanded = False
current_segment = segments[i]
next_segment = segments[i + 1]
delta = next_segment['start'] - current_segment['end']
if (max_expand_size is not None and delta <= max_expand_size):
# Just expand the current segment
current_segment = current_segment.copy()
current_segment['expand_amount'] = delta
current_segment['end'] = next_segment['start']
expanded = True
result.append(current_segment)
# Add a gap to the next segment if needed
if (delta >= 0 and not expanded):
result.append({ 'start': current_segment['end'], 'end': next_segment['start'], 'gap': True } )
# Add last segment
last_segment = segments[-1]
result.append(last_segment)
# Also include total duration if specified
if (total_duration is not None):
last_segment = result[-1]
delta = total_duration - last_segment['end']
if (delta > 0):
if (max_expand_size is not None and delta <= max_expand_size):
# Expand the last segment
last_segment = last_segment.copy()
last_segment['expand_amount'] = delta
last_segment['end'] = total_duration
result[-1] = last_segment
else:
result.append({ 'start': last_segment['end'], 'end': total_duration, 'gap': True } )
return result
def adjust_timestamp(self, segments: Iterator[dict], adjust_seconds: float, max_source_time: float = None):
result = []
for segment in segments:
segment_start = float(segment['start'])
segment_end = float(segment['end'])
# Filter segments?
if (max_source_time is not None):
if (segment_start > max_source_time):
continue
segment_end = min(max_source_time, segment_end)
new_segment = segment.copy()
# Add to start and end
new_segment['start'] = segment_start + adjust_seconds
new_segment['end'] = segment_end + adjust_seconds
# Handle words
if ('words' in new_segment):
for word in new_segment['words']:
# Adjust start and end
word['start'] = word['start'] + adjust_seconds
word['end'] = word['end'] + adjust_seconds
result.append(new_segment)
return result
def multiply_timestamps(self, timestamps: List[Dict[str, Any]], factor: float):
result = []
for entry in timestamps:
start = entry['start']
end = entry['end']
result.append({
'start': start * factor,
'end': end * factor
})
return result
class VadSileroTranscription(AbstractTranscription):
def __init__(self, sampling_rate: int = 16000, cache: ModelCache = None):
super().__init__(sampling_rate=sampling_rate)
self.model = None
self.cache = cache
self._initialize_model()
def _initialize_model(self):
if (self.cache is not None):
model_key = "VadSileroTranscription"
self.model, self.get_speech_timestamps = self.cache.get(model_key, self._create_model)
print("Loaded Silerio model from cache.")
else:
self.model, self.get_speech_timestamps = self._create_model()
print("Created Silerio model")
def _create_model(self):
model, utils = torch.hub.load(repo_or_dir='snakers4/silero-vad', model='silero_vad')
# Silero does not benefit from multi-threading
torch.set_num_threads(1) # JIT
(get_speech_timestamps, _, _, _, _) = utils
return model, get_speech_timestamps
def get_transcribe_timestamps(self, audio: str, config: TranscriptionConfig, start_time: float, end_time: float):
result = []
print("Getting timestamps from audio file: {}, start: {}, duration: {}".format(audio, start_time, end_time))
perf_start_time = time.perf_counter()
# Divide procesisng of audio into chunks
chunk_start = start_time
while (chunk_start < end_time):
chunk_duration = min(end_time - chunk_start, VAD_MAX_PROCESSING_CHUNK)
print("Processing VAD in chunk from {} to {}".format(format_timestamp(chunk_start), format_timestamp(chunk_start + chunk_duration)))
wav = self.get_audio_segment(audio, str(chunk_start), str(chunk_duration))
sample_timestamps = self.get_speech_timestamps(wav, self.model, sampling_rate=self.sampling_rate, threshold=SPEECH_TRESHOLD)
seconds_timestamps = self.multiply_timestamps(sample_timestamps, factor=1 / self.sampling_rate)
adjusted = self.adjust_timestamp(seconds_timestamps, adjust_seconds=chunk_start, max_source_time=chunk_start + chunk_duration)
#pprint(adjusted)
result.extend(adjusted)
chunk_start += chunk_duration
perf_end_time = time.perf_counter()
print("VAD processing took {} seconds".format(perf_end_time - perf_start_time))
return result
def __getstate__(self):
# We only need the sampling rate
return { 'sampling_rate': self.sampling_rate }
def __setstate__(self, state):
self.sampling_rate = state['sampling_rate']
self.model = None
# Use the global cache
self.cache = GLOBAL_MODEL_CACHE
self._initialize_model()
# A very simple VAD that just marks every N seconds as speech
class VadPeriodicTranscription(AbstractTranscription):
def __init__(self, sampling_rate: int = 16000):
super().__init__(sampling_rate=sampling_rate)
def is_transcribe_timestamps_fast(self):
# This is a very fast VAD - no need to parallelize it
return True
def get_transcribe_timestamps(self, audio: str, config: PeriodicTranscriptionConfig, start_time: float, end_time: float):
result = []
# Generate a timestamp every N seconds
start_timestamp = start_time
while (start_timestamp < end_time):
end_timestamp = min(start_timestamp + config.periodic_duration, end_time)
segment_duration = end_timestamp - start_timestamp
# Minimum duration is 1 second
if (segment_duration >= 1):
result.append( { 'start': start_timestamp, 'end': end_timestamp } )
start_timestamp = end_timestamp
return result
def get_audio_duration(file: str):
return float(ffmpeg.probe(file)["format"]["duration"])
def load_audio(file: str, sample_rate: int = 16000,
start_time: str = None, duration: str = None):
"""
Open an audio file and read as mono waveform, resampling as necessary
Parameters
----------
file: str
The audio file to open
sr: int
The sample rate to resample the audio if necessary
start_time: str
The start time, using the standard FFMPEG time duration syntax, or None to disable.
duration: str
The duration, using the standard FFMPEG time duration syntax, or None to disable.
Returns
-------
A NumPy array containing the audio waveform, in float32 dtype.
"""
try:
inputArgs = {'threads': 0}
if (start_time is not None):
inputArgs['ss'] = start_time
if (duration is not None):
inputArgs['t'] = duration
# This launches a subprocess to decode audio while down-mixing and resampling as necessary.
# Requires the ffmpeg CLI and `ffmpeg-python` package to be installed.
out, _ = (
ffmpeg.input(file, **inputArgs)
.output("-", format="s16le", acodec="pcm_s16le", ac=1, ar=sample_rate)
.run(cmd="ffmpeg", capture_stdout=True, capture_stderr=True)
)
except ffmpeg.Error as e:
raise RuntimeError(f"Failed to load audio: {e.stderr.decode()}")
return np.frombuffer(out, np.int16).flatten().astype(np.float32) / 32768.0