1 files changed, 151 insertions, 0 deletions
diff --git a/stacks/crdop/lib/sound_proxy_oss.py b/stacks/crdop/lib/sound_proxy_oss.py
new file mode 100644
index 0000000..66cf765
--- /dev/null
+++ b/stacks/crdop/lib/sound_proxy_oss.py
@@ -0,0 +1,151 @@
+"""
+MAX25 sound-proxy — FreeBSD/OSS capture and playback.
+
+Uses `sox` with OSS devices when available; falls back to raw /dev/dsp read/write.
+"""
+from __future__ import annotations
+
+import os
+import shutil
+import subprocess
+import threading
+from dataclasses import dataclass
+from typing import Callable, Optional
+
+
+@dataclass
+class OssSoundConfig:
+    capture: str = "/dev/dsp"
+    playback: str = "/dev/dsp"
+    sample_rate: int = 48000
+    channels: int = 1
+
+
+class OssSoundProxy:
+    def __init__(self, cfg: OssSoundConfig) -> None:
+        self.cfg = cfg
+        self._rec_proc: Optional[subprocess.Popen[bytes]] = None
+        self._dsp_fd: Optional[int] = None
+        self._stop = threading.Event()
+        self._use_sox = shutil.which("sox") is not None
+
+    def _sox_capture_cmd(self) -> list[str]:
+        dev = self.cfg.capture
+        return [
+            "sox",
+            "-q",
+            "-t",
+            "oss",
+            dev,
+            "-r",
+            str(self.cfg.sample_rate),
+            "-c",
+            str(self.cfg.channels),
+            "-b",
+            "16",
+            "-e",
+            "signed-integer",
+            "-t",
+            "raw",
+            "-",
+        ]
+
+    def _sox_play_cmd(self) -> list[str]:
+        dev = self.cfg.playback
+        return [
+            "sox",
+            "-q",
+            "-t",
+            "raw",
+            "-r",
+            str(self.cfg.sample_rate),
+            "-c",
+            str(self.cfg.channels),
+            "-b",
+            "16",
+            "-e",
+            "signed-integer",
+            "-",
+            "-t",
+            "oss",
+            dev,
+        ]
+
+    def start_capture(self) -> None:
+        if self._use_sox:
+            self._rec_proc = subprocess.Popen(
+                self._sox_capture_cmd(),
+                stdout=subprocess.PIPE,
+                stderr=subprocess.DEVNULL,
+            )
+            return
+        flags = os.O_RDONLY
+        try:
+            self._dsp_fd = os.open(self.cfg.capture, flags)
+        except OSError as exc:
+            raise RuntimeError(f"OSS open {self.cfg.capture}: {exc}") from exc
+
+    def read_capture(self, nbytes: int) -> bytes:
+        if self._rec_proc is not None and self._rec_proc.stdout is not None:
+            return self._rec_proc.stdout.read(nbytes) or b""
+        if self._dsp_fd is not None:
+            try:
+                return os.read(self._dsp_fd, nbytes) or b""
+            except OSError:
+                return b""
+        return b""
+
+    def play_pcm(self, pcm: bytes) -> None:
+        if not pcm:
+            return
+        if self._use_sox:
+            subprocess.run(
+                self._sox_play_cmd(),
+                input=pcm,
+                check=False,
+                stdout=subprocess.DEVNULL,
+                stderr=subprocess.DEVNULL,
+            )
+            return
+        try:
+            fd = os.open(self.cfg.playback, os.O_WRONLY)
+        except OSError:
+            return
+        try:
+            os.write(fd, pcm)
+        finally:
+            os.close(fd)
+
+    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 = max(256, (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()
+        if self._rec_proc is not None and self._rec_proc.poll() is None:
+            self._rec_proc.terminate()
+            try:
+                self._rec_proc.wait(timeout=1.0)
+            except subprocess.TimeoutExpired:
+                self._rec_proc.kill()
+        self._rec_proc = None
+        if self._dsp_fd is not None:
+            try:
+                os.close(self._dsp_fd)
+            except OSError:
+                pass
+            self._dsp_fd = None