1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
"""
MAX25 sound-proxy — host audio capture/playback.
Linux/KLinux: ALSA (arecord/aplay).
FreeBSD: OSS via sound_proxy_oss (sox or /dev/dsp).
"""
from __future__ import annotations
import os
import shutil
import subprocess
import sys
import threading
from dataclasses import dataclass
from pathlib import Path
from typing import Callable, Optional, Protocol, runtime_checkable
@dataclass
class SoundConfig:
capture: str = "default"
playback: str = "default"
sample_rate: int = 48000
channels: int = 1
period_frames: int = 256
forbid_pulse: bool = True
backend: str = "" # alsa | oss — empty = auto from platform
@runtime_checkable
class SoundProxyProto(Protocol):
def start_capture(self) -> None: ...
def read_capture(self, nbytes: int) -> bytes: ...
def play_pcm(self, pcm: bytes) -> None: ...
def sniff_loop(
self,
chunk_symbols: int,
on_pcm: Callable[[bytes], None],
stop: Optional[threading.Event] = None,
) -> None: ...
def close(self) -> None: ...
def _detect_backend(cfg: SoundConfig) -> str:
explicit = (cfg.backend or os.environ.get("MAX25_AUDIO_BACKEND", "")).strip().lower()
if explicit in ("alsa", "oss"):
return explicit
if sys.platform.startswith("freebsd"):
return "oss"
return "alsa"
def create_sound_proxy(cfg: SoundConfig) -> SoundProxyProto:
backend = _detect_backend(cfg)
if backend == "oss":
from sound_proxy_oss import OssSoundConfig, OssSoundProxy
cap = cfg.capture if cfg.capture not in ("", "default") else "/dev/dsp"
pb = cfg.playback if cfg.playback not in ("", "default") else cap
return OssSoundProxy(
OssSoundConfig(
capture=cap,
playback=pb,
sample_rate=cfg.sample_rate,
channels=cfg.channels,
)
)
return AlsaSoundProxy(cfg)
class AlsaSoundProxy:
def __init__(self, cfg: SoundConfig) -> None:
self.cfg = cfg
self._rec_proc: Optional[subprocess.Popen[bytes]] = None
self._play_proc: Optional[subprocess.Popen[bytes]] = None
self._stop = threading.Event()
def _alsa_env(self) -> dict[str, str]:
env = os.environ.copy()
if self.cfg.forbid_pulse:
env.pop("PULSE_SERVER", None)
env.pop("PIPEWIRE_RUNTIME_DIR", None)
env["PULSE_SERVER"] = ""
return env
@staticmethod
def _check_device(name: str) -> None:
low = name.lower()
if low in ("default", "pulse", "pipewire") or "pulse" in low or "pipewire" in low:
raise ValueError(
f"audio device {name!r} not allowed — use hw: or plughw: (kernel ALSA)"
)
def start_capture(self) -> None:
if not shutil.which("arecord"):
raise RuntimeError("arecord not found — install alsa-utils")
self._check_device(self.cfg.capture)
cmd = [
"arecord",
"-q",
"-D",
self.cfg.capture,
"-f",
"S16_LE",
"-r",
str(self.cfg.sample_rate),
"-c",
str(self.cfg.channels),
"-t",
"raw",
]
self._rec_proc = subprocess.Popen(
cmd,
stdout=subprocess.PIPE,
stderr=subprocess.DEVNULL,
env=self._alsa_env(),
)
def read_capture(self, nbytes: int) -> bytes:
if self._rec_proc is None or self._rec_proc.stdout is None:
return b""
return self._rec_proc.stdout.read(nbytes) or b""
def play_pcm(self, pcm: bytes) -> None:
if not pcm:
return
if not shutil.which("aplay"):
raise RuntimeError("aplay not found — install alsa-utils")
self._check_device(self.cfg.playback)
cmd = [
"aplay",
"-q",
"-D",
self.cfg.playback,
"-f",
"S16_LE",
"-r",
str(self.cfg.sample_rate),
"-c",
str(self.cfg.channels),
"-t",
"raw",
]
subprocess.run(
cmd,
input=pcm,
check=False,
env=self._alsa_env(),
stdout=subprocess.DEVNULL,
stderr=subprocess.DEVNULL,
)
def sniff_loop(
self,
chunk_symbols: int,
on_pcm: Callable[[bytes], None],
stop: Optional[threading.Event] = None,
) -> None:
stop_ev = stop or self._stop
frame_bytes = (self.cfg.sample_rate // 1200) * 2 * chunk_symbols
self.start_capture()
try:
while not stop_ev.is_set():
chunk = self.read_capture(frame_bytes)
if not chunk:
break
on_pcm(chunk)
finally:
self.close()
def close(self) -> None:
self._stop.set()
for proc in (self._rec_proc, self._play_proc):
if proc is not None and proc.poll() is None:
proc.terminate()
try:
proc.wait(timeout=1.0)
except subprocess.TimeoutExpired:
proc.kill()
self._rec_proc = None
self._play_proc = None
# Backward-compatible alias
SoundProxy = AlsaSoundProxy
|
