LiveTranslate / audio_capture.py
fasdfsa's picture
init
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import logging
import threading
import queue
import time
import numpy as np
import pyaudiowpatch as pyaudio
log = logging.getLogger("LiveTrans.Audio")
DEVICE_CHECK_INTERVAL = 2.0 # seconds
def list_output_devices():
"""Return list of WASAPI output device names."""
pa = pyaudio.PyAudio()
devices = []
wasapi_idx = None
for i in range(pa.get_host_api_count()):
info = pa.get_host_api_info_by_index(i)
if "WASAPI" in info["name"]:
wasapi_idx = info["index"]
break
if wasapi_idx is not None:
for i in range(pa.get_device_count()):
dev = pa.get_device_info_by_index(i)
if (dev["hostApi"] == wasapi_idx
and dev["maxOutputChannels"] > 0
and not dev.get("isLoopbackDevice", False)):
devices.append(dev["name"])
pa.terminate()
return devices
class AudioCapture:
"""Capture system audio via WASAPI loopback using pyaudiowpatch."""
def __init__(self, device=None, sample_rate=16000, chunk_duration=0.5):
self.sample_rate = sample_rate
self.chunk_duration = chunk_duration
self.audio_queue = queue.Queue(maxsize=100)
self._stream = None
self._running = False
self._device_name = device
self._pa = pyaudio.PyAudio()
self._read_thread = None
self._native_channels = 2
self._native_rate = 44100
self._current_device_name = None
self._lock = threading.Lock()
def _get_wasapi_info(self):
for i in range(self._pa.get_host_api_count()):
info = self._pa.get_host_api_info_by_index(i)
if "WASAPI" in info["name"]:
return info
return None
def _get_default_output_name(self):
wasapi_info = self._get_wasapi_info()
if wasapi_info is None:
return None
default_idx = wasapi_info["defaultOutputDevice"]
default_dev = self._pa.get_device_info_by_index(default_idx)
return default_dev["name"]
@staticmethod
def _query_current_default():
"""Create a fresh PA instance to get the actual current default device."""
pa = pyaudio.PyAudio()
try:
for i in range(pa.get_host_api_count()):
info = pa.get_host_api_info_by_index(i)
if "WASAPI" in info["name"]:
default_idx = info["defaultOutputDevice"]
dev = pa.get_device_info_by_index(default_idx)
return dev["name"]
finally:
pa.terminate()
return None
def _find_loopback_device(self):
"""Find WASAPI loopback device for the default output."""
wasapi_info = self._get_wasapi_info()
if wasapi_info is None:
raise RuntimeError("WASAPI host API not found")
default_output_idx = wasapi_info["defaultOutputDevice"]
default_output = self._pa.get_device_info_by_index(default_output_idx)
log.info(f"Default output: {default_output['name']}")
target_name = self._device_name or default_output["name"]
for i in range(self._pa.get_device_count()):
dev = self._pa.get_device_info_by_index(i)
if dev["hostApi"] == wasapi_info["index"] and dev.get("isLoopbackDevice", False):
if target_name in dev["name"]:
return dev
# Fallback: any loopback device
for i in range(self._pa.get_device_count()):
dev = self._pa.get_device_info_by_index(i)
if dev.get("isLoopbackDevice", False):
return dev
raise RuntimeError("No WASAPI loopback device found")
def _open_stream(self):
"""Open stream for current default loopback device."""
loopback_dev = self._find_loopback_device()
self._native_channels = loopback_dev["maxInputChannels"]
self._native_rate = int(loopback_dev["defaultSampleRate"])
self._current_device_name = loopback_dev["name"]
log.info(f"Loopback device: {loopback_dev['name']}")
log.info(f"Native: {self._native_rate}Hz, {self._native_channels}ch -> {self.sample_rate}Hz mono")
native_chunk = int(self._native_rate * self.chunk_duration)
self._stream = self._pa.open(
format=pyaudio.paFloat32,
channels=self._native_channels,
rate=self._native_rate,
input=True,
input_device_index=loopback_dev["index"],
frames_per_buffer=native_chunk,
)
def _close_stream(self):
if self._stream:
try:
self._stream.stop_stream()
self._stream.close()
except Exception:
pass
self._stream = None
def set_device(self, device_name):
"""Change capture device at runtime. None = system default."""
if device_name == self._device_name:
return
log.info(f"Audio device changed: {self._device_name} -> {device_name}")
self._device_name = device_name
if self._running:
self._restart_stream()
def _restart_stream(self):
"""Restart stream with new default device."""
with self._lock:
self._close_stream()
# Refresh device list
self._pa.terminate()
self._pa = pyaudio.PyAudio()
self._open_stream()
def _read_loop(self):
"""Synchronous read loop in a background thread."""
last_device_check = time.monotonic()
while self._running:
# Auto-switch only when using system default
now = time.monotonic()
if now - last_device_check > DEVICE_CHECK_INTERVAL:
last_device_check = now
if self._device_name is None:
try:
current_default = self._query_current_default()
if current_default and self._current_device_name and \
current_default not in self._current_device_name:
log.info(f"System default output changed: "
f"{self._current_device_name} -> {current_default}")
log.info("Restarting audio capture for new device...")
self._restart_stream()
log.info(f"Audio capture restarted on: {self._current_device_name}")
except Exception as e:
log.warning(f"Device check error: {e}")
native_chunk = int(self._native_rate * self.chunk_duration)
try:
with self._lock:
if not self._stream:
continue
data = self._stream.read(native_chunk, exception_on_overflow=False)
except Exception as e:
log.warning(f"Read error (device may have changed): {e}")
try:
time.sleep(0.5)
self._restart_stream()
log.info("Stream restarted after read error")
except Exception as re:
log.error(f"Restart failed: {re}")
time.sleep(1)
continue
audio = np.frombuffer(data, dtype=np.float32)
# Mix to mono
if self._native_channels > 1:
audio = audio.reshape(-1, self._native_channels).mean(axis=1)
# Resample to target rate
if self._native_rate != self.sample_rate:
ratio = self.sample_rate / self._native_rate
n_out = int(len(audio) * ratio)
indices = np.arange(n_out) / ratio
indices = np.clip(indices, 0, len(audio) - 1)
idx_floor = indices.astype(np.int64)
idx_ceil = np.minimum(idx_floor + 1, len(audio) - 1)
frac = (indices - idx_floor).astype(np.float32)
audio = audio[idx_floor] * (1 - frac) + audio[idx_ceil] * frac
try:
self.audio_queue.put_nowait(audio)
except queue.Full:
self.audio_queue.get_nowait() # Drop oldest
self.audio_queue.put_nowait(audio)
def start(self):
self._open_stream()
self._running = True
self._read_thread = threading.Thread(target=self._read_loop, daemon=True)
self._read_thread.start()
log.info("Audio capture started")
def stop(self):
self._running = False
if self._read_thread:
self._read_thread.join(timeout=3)
self._close_stream()
log.info("Audio capture stopped")
def get_audio(self, timeout=1.0):
try:
return self.audio_queue.get(timeout=timeout)
except queue.Empty:
return None
def __del__(self):
if self._pa:
self._pa.terminate()