Merge pull request #16 from hakanekin/fix/pw-record-raw-compat

Handle pw-record versions without --raw support

audio.py

@@ -445,7 +445,7 @@ def _pulse_record(target):
         return cmd
     if shutil.which("pw-record"):
         cmd = [
-            "pw-record", "--raw", f"--rate={RATE}",
+            "pw-record", *_pw_record_raw_option(), f"--rate={RATE}",
             f"--channels={CHANNELS}", "--format=s16",
         ]
         if target:
@@ -455,6 +455,28 @@ def _pulse_record(target):
     return []
 
 
+def _pw_record_raw_option():
+    """Use --raw only on pw-record releases that provide it.
+
+    PipeWire gained --raw in 1.4, and in the same release stopped treating a
+    filename of "-" as raw on its own: before it, the option is refused and the
+    recorder dies before any sound arrives; after it, leaving the option out
+    wraps the stream in a container the rest of this file would read as noise.
+    Ubuntu 24.04 and anything else still on 1.0 or 1.2 sit on the near side of
+    that line, so ask the installed binary which form it understands.
+    """
+    try:
+        result = subprocess.run(
+            ["pw-record", "--help"], capture_output=True, text=True, timeout=2
+        )
+        help_text = (result.stdout or "") + (result.stderr or "")
+    except (subprocess.SubprocessError, OSError):
+        return ["--raw"]  # preserve the existing command when probing itself fails
+    if not help_text.strip():
+        return ["--raw"]
+    return ["--raw"] if "--raw" in help_text else []
+
+
 def _pulse_meeting(mic_target, system_target):
     return [
         "ffmpeg", "-hide_banner", "-nostdin", "-loglevel", "error",

tests/test_audio.py

@@ -238,6 +238,14 @@ class FakeProcess:
 class RecordingCommand(OnLinux, DikteTest):
     """Which program captures the microphone, and how it is asked to."""
 
+    def setUp(self):
+        super().setUp()
+        # Whether pw-record takes --raw is read off the installed binary, and
+        # what is being tested here is the command rather than the machine the
+        # test is running on. PwRecordRawOption covers the reading itself.
+        self.enterContext(mock.patch.object(
+            audio, "_pw_record_raw_option", return_value=["--raw"]))
+
     def test_parec_is_preferred(self):
         """It speaks to PulseAudio and to PipeWire's compatibility service, so
         it is the one that works on both desktops."""
@@ -288,9 +296,45 @@ class RecordingCommand(OnLinux, DikteTest):
                                   if arg.startswith(flag)])
 
 
+class PwRecordRawOption(DikteTest):
+    """Two pw-record generations want opposite commands for the same stream.
+
+    PipeWire 1.4 added --raw and stopped treating a filename of "-" as raw on
+    its own, so the option is refused by everything older and needed by
+    everything newer. The help text is the only thing that tells them apart.
+    """
+
+    def option(self, **run):
+        with mock.patch.object(audio.subprocess, "run", **run):
+            return audio._pw_record_raw_option()
+
+    def test_a_version_that_offers_raw_is_asked_for_it(self):
+        self.assertEqual(["--raw"], self.option(
+            return_value=FakeCompleted(stdout="  -a, --raw   RAW mode\n")))
+
+    def test_a_version_without_it_is_not(self):
+        self.assertEqual([], self.option(
+            return_value=FakeCompleted(stdout="  --rate  Sample rate\n")))
+
+    def test_help_that_could_not_be_read_keeps_the_option(self):
+        """Whatever is installed, the command that worked before this check
+        existed is the safer guess."""
+        self.assertEqual(["--raw"], self.option(side_effect=OSError))
+        self.assertEqual(["--raw"], self.option(
+            side_effect=subprocess.TimeoutExpired("pw-record", 2)))
+
+    def test_help_that_said_nothing_keeps_it_too(self):
+        self.assertEqual(["--raw"], self.option(return_value=FakeCompleted()))
+
+
 class RecorderChain(OnLinux, DikteTest):
     """Start to WAV, with pw-record faked out."""
 
+    def setUp(self):
+        super().setUp()
+        self.enterContext(mock.patch.object(
+            audio, "_pw_record_raw_option", return_value=["--raw"]))
+
     def record(self, data, target="", max_seconds=300):
         recorder = audio.Recorder()
         results = []