Files
WhisperLive/server.py
T

291 lines
10 KiB
Python

import websockets
import pickle, struct, time, pyaudio
import threading
import os, json
import wave
import textwrap
import logging
logging.basicConfig(level = logging.INFO)
from collections import deque
from dataclasses import dataclass
import torch
import numpy as np
from websockets.sync import server
from websockets.sync.server import serve
from transcriber import WhisperModel
clients = {}
SERVER_READY = "SERVER_READY"
def recv_audio(websocket):
"""
Receive audio chunks from client in an infinite loop.
"""
global clients
options = websocket.recv()
options = json.loads(options)
client = ServeClient(
websocket,
multilingual=options["multilingual"],
language=options["language"],
task=options["task"]
)
clients[websocket] = client
while True:
try:
frame_data = websocket.recv()
frame_np = np.frombuffer(frame_data, np.float32)
clients[websocket].add_frames(frame_np)
except Exception as e:
clients[websocket].cleanup()
clients.pop(websocket)
logging.info("Connection Closed.")
break
class ServeClient:
RATE = 16000
def __init__(self, websocket, task="transcribe", device=None, multilingual=False, language=None):
self.data = b""
self.frames = b""
self.language = language
self.task = task
self.transcriber = WhisperModel(
"small" if multilingual else "small.en",
device=device if device else "cuda",
compute_type="float16",
local_files_only=False,
)
# voice activity detection model
self.vad_model, _ = torch.hub.load(repo_or_dir='snakers4/silero-vad',
model='silero_vad',
force_reload=True,
onnx=True
)
self.vad_threshold = 0.4
self.timestamp_offset = 0.0
self.frames_np = None
self.frames_offset = 0.0
self.text = []
self.current_out = ''
self.prev_out = ''
self.t_start=None
self.exit = False
self.same_output_threshold = 0
self.show_prev_out_thresh = 5 # if pause(no output from whisper) show previous output for 5 seconds
self.add_pause_thresh = 3 # add a blank to segment list as a pause(no speech) for 3 seconds
self.transcript = []
self.send_last_n_segments = 10
# text formatting
self.wrapper = textwrap.TextWrapper(width=50)
self.pick_previous_segments = 2
# threading
self.websocket = websocket
self.trans_thread = threading.Thread(target=self.speech_to_text)
self.trans_thread.start()
self.websocket.send(json.dumps(SERVER_READY))
def fill_output(self, output):
"""
Format output with current and previous complete segments
into two lines of 50 characters.
Args:
output(str): current incomplete segment
Returns:
transcription wrapped in two lines
"""
text = ''
pick_prev = min(len(self.text), self.pick_previous_segments)
for seg in self.text[-pick_prev:]:
# discard everything before a 3 second pause
if seg == '':
text = ''
else:
text += seg
wrapped = "".join(text + output)
return wrapped
def add_frames(self, frame_np):
try:
speech_prob = self.vad_model(torch.from_numpy(frame_np.copy()), self.RATE).item()
if speech_prob < self.vad_threshold:
return
except Exception as e:
logging.error(e)
return
if self.frames_np is not None and self.frames_np.shape[0] > 45*self.RATE:
self.frames_offset += 45.0
self.frames_np = self.frames_np[int(30*self.RATE):]
if self.frames_np is None:
self.frames_np = frame_np.copy()
else:
self.frames_np = np.concatenate((self.frames_np, frame_np), axis=0)
def speech_to_text(self):
"""
Process audio stream in an infinite loop.
"""
while True:
if self.exit:
logging.info("Exiting speech to text thread")
break
if self.frames_np is None:
continue
# clip audio if the current chunk exceeds 30 seconds, this basically implies that
# no valid segment for the last 30 seconds from whisper
if self.frames_np[int((self.timestamp_offset - self.frames_offset)*self.RATE):].shape[0] > 25 * self.RATE:
duration = self.frames_np.shape[0] / self.RATE
self.timestamp_offset = self.frames_offset + duration - 5
samples_take = max(0, (self.timestamp_offset - self.frames_offset)*self.RATE)
input_bytes = self.frames_np[int(samples_take):].copy()
duration = input_bytes.shape[0] / self.RATE
if duration<1.0:
continue
try:
input_sample = input_bytes.copy()
# set previous complete segment as initial prompt
if len(self.text) and self.text[-1] != '':
initial_prompt = self.text[-1]
else:
initial_prompt = None
# whisper transcribe with prompt
result = self.transcriber.transcribe(
input_sample,
initial_prompt=initial_prompt,
language=self.language,
task=self.task
)
if len(result):
self.t_start = None
last_segment = self.update_segments(result, duration)
if len(self.transcript) < self.send_last_n_segments:
segments = self.transcript
else:
segments = self.transcript[-self.send_last_n_segments:]
if last_segment is not None:
segments = segments + [last_segment]
try:
self.websocket.send(json.dumps(segments))
except Exception as e:
logging.info(f"[ERROR]: {e}")
else:
# show previous output if there is pause i.e. no output from whisper
segments = []
if self.t_start is None: self.t_start = time.time()
if time.time() - self.t_start < self.show_prev_out_thresh:
if len(self.transcript) < self.send_last_n_segments:
segments = self.transcript
else:
segments = self.transcript[-self.send_last_n_segments:]
# add a blank if there is no speech for 3 seconds
if len(self.text) and self.text[-1] != '':
if time.time() - self.t_start > self.add_pause_thresh:
self.text.append('')
try:
self.websocket.send(json.dumps(segments))
except Exception as e:
logging.info(f"[INFO]: {e}")
except Exception as e:
logging.info(f"[INFO]: {e}")
time.sleep(0.01)
def update_segments(self, segments, duration):
"""
Processes the segments from whisper. Appends all the segments to the list
except for the last segment assuming that it is incomplete.
Args:
segments(dict) : dictionary of segments as returned by whisper
duration(float): duration of the current chunk
Returns:
transcription for the current chunk
"""
offset = None
self.current_out = ''
last_segment = None
# process complete segments
if len(segments) > 1:
for i, s in enumerate(segments[:-1]):
text_ = s.text
self.text.append(text_)
start, end = self.timestamp_offset + s.start, self.timestamp_offset + min(duration, s.end)
self.transcript.append(
{
'start': start,
'end': end,
'text': text_
}
)
offset = min(duration, s.end)
self.current_out += segments[-1].text
last_segment = {
'start': self.timestamp_offset + segments[-1].start,
'end': self.timestamp_offset + min(duration, segments[-1].end),
'text': self.current_out
}
# if same incomplete segment is seen multiple times then update the offset
# and append the segment to the list
if self.current_out.strip() == self.prev_out.strip() and self.current_out != '':
self.same_output_threshold += 1
else:
self.same_output_threshold = 0
if self.same_output_threshold > 5:
if not len(self.text) or self.text[-1].strip().lower()!=self.current_out.strip().lower():
self.text.append(self.current_out)
self.transcript.append(
{
'start': self.timestamp_offset,
'end': self.timestamp_offset + duration,
'text': self.current_out
}
)
self.current_out = ''
offset = duration
self.same_output_threshold = 0
last_segment = None
else:
self.prev_out = self.current_out
# update offset
if offset is not None:
self.timestamp_offset += offset
return last_segment
def cleanup(self):
logging.info("Cleaning up.")
self.exit = True
self.transcriber.destroy()
if __name__ == "__main__":
with serve(recv_audio, "0.0.0.0", 9090) as server:
server.serve_forever()