Bug 1502313 - Remove concurrent audio input device limit. r=padenot

The limit only applied within a child process.

However, within a child process we already share cubeb stream when requesting
the same device multiple times, and disallow capturing from more than one device
at a time.

This limit no longer has any effect.

Differential Revision: https://phabricator.services.mozilla.com/D10339

--HG--
extra : moz-landing-system : lando

dom/media/CubebUtils.cpp

@@ -38,8 +38,6 @@
 #define PREF_CUBEB_OUTPUT_DEVICE "media.cubeb.output_device"
 #define PREF_CUBEB_LATENCY_PLAYBACK "media.cubeb_latency_playback_ms"
 #define PREF_CUBEB_LATENCY_MSG "media.cubeb_latency_msg_frames"
-// This only works when audio remoting is active, and pulseaudio is the backend.
-#define PREF_CUBEB_MAX_INPUT_STREAMS "media.cubeb_max_input_streams"
 // Allows to get something non-default for the preferred sample-rate, to allow
 // troubleshooting in the field and testing.
 #define PREF_CUBEB_FORCE_SAMPLE_RATE "media.cubeb.force_sample_rate"
@@ -131,9 +129,6 @@ cubeb* sCubebContext;
 double sVolumeScale = 1.0;
 uint32_t sCubebPlaybackLatencyInMilliseconds = 100;
 uint32_t sCubebMSGLatencyInFrames = 512;
-// Maximum number of audio input streams that can be open at once. This pref is
-// only used when remoting is on, and we're using PulseAudio as a backend.
-uint32_t sCubebMaxInputStreams = 1;
 // If sCubebForcedSampleRate is zero, PreferredSampleRate will return the
 // preferred sample-rate for the audio backend in use. Otherwise, it will be
 // used as the preferred sample-rate.
@@ -238,9 +233,6 @@ void PrefChanged(const char* aPref, void* aClosure)
     // We don't want to limit the upper limit too much, so that people can
     // experiment.
     sCubebMSGLatencyInFrames = std::min<uint32_t>(std::max<uint32_t>(value, 128), 1e6);
-  } else if (strcmp(aPref, PREF_CUBEB_MAX_INPUT_STREAMS) == 0) {
-    StaticMutexAutoLock lock(sMutex);
-    sCubebMaxInputStreams = Preferences::GetUint(aPref);
   } else if (strcmp(aPref, PREF_CUBEB_FORCE_SAMPLE_RATE) == 0) {
     StaticMutexAutoLock lock(sMutex);
     sCubebForcedSampleRate = Preferences::GetUint(aPref);
@@ -571,19 +563,12 @@ uint32_t GetCubebMSGLatencyInFrames(cubeb_stream_params * params)
 #endif
 }
 
-uint32_t GetMaxInputStreams()
-{
-  StaticMutexAutoLock lock(sMutex);
-  return sCubebMaxInputStreams;
-}
-
 static const char* gInitCallbackPrefs[] = {
   PREF_VOLUME_SCALE,           PREF_CUBEB_OUTPUT_DEVICE,
   PREF_CUBEB_LATENCY_PLAYBACK, PREF_CUBEB_LATENCY_MSG,
   PREF_CUBEB_BACKEND,          PREF_CUBEB_FORCE_NULL_CONTEXT,
   PREF_CUBEB_SANDBOX,          PREF_AUDIOIPC_POOL_SIZE,
-  PREF_CUBEB_MAX_INPUT_STREAMS, PREF_AUDIOIPC_STACK_SIZE,
-  nullptr,
+  PREF_AUDIOIPC_STACK_SIZE,    nullptr,
 };
 static const char* gCallbackPrefs[] = {
   PREF_CUBEB_FORCE_SAMPLE_RATE,

dom/media/CubebUtils.h

@@ -50,7 +50,6 @@ void GetDeviceCollection(nsTArray<RefPtr<AudioDeviceInfo>>& aDeviceInfos,
                          Side aSide);
 cubeb_stream_prefs GetDefaultStreamPrefs();
 char* GetForcedOutputDevice();
-uint32_t GetMaxInputStreams();
 
 #ifdef MOZ_WIDGET_ANDROID
 uint32_t AndroidGetAudioOutputSampleRate();

dom/media/tests/mochitest/head.js

@@ -422,8 +422,7 @@ function setupEnvironment() {
       ['media.getusermedia.screensharing.enabled', true],
       ['media.getusermedia.window.focus_source.enabled', false],
       ['media.recorder.audio_node.enabled', true],
-      ['media.webaudio.audiocontextoptions-samplerate.enabled', true],
-      ['media.cubeb_max_input_streams', 10000]
+      ['media.webaudio.audiocontextoptions-samplerate.enabled', true]
     ]
   };
 

dom/media/webrtc/MediaEngineWebRTCAudio.cpp

@@ -32,10 +32,6 @@ using namespace webrtc;
 #define MAX_CHANNELS 2
 #define MAX_SAMPLING_FREQ 48000 // Hz - multiple of 100
 
-#ifdef MOZ_PULSEAUDIO
-static uint32_t sInputStreamsOpen = 0;
-#endif
-
 namespace mozilla {
 
 #ifdef LOG
@@ -656,23 +652,7 @@ MediaEngineWebRTCMicrophoneSource::Start(const RefPtr<const AllocationHandle>&)
     return NS_ERROR_FAILURE;
   }
 
-  // On Linux with PulseAudio, we still only allow a certain number of audio
-  // input stream in each content process, because of issues related to audio
-  // remoting and PulseAudio.
-#ifdef MOZ_PULSEAUDIO
-  // When remoting, cubeb reports it's using the "remote" backend instead of the
-  // backend on the other side of the IPC.
-  const char* backend = cubeb_get_backend_id(CubebUtils::GetCubebContext());
-  if (strstr(backend, "remote") &&
-      sInputStreamsOpen == CubebUtils::GetMaxInputStreams()) {
-    LOG(("%p Already capturing audio in this process, aborting", this));
-    return NS_ERROR_FAILURE;
-  }
 
-  sInputStreamsOpen++;
-#endif
-
-  AssertIsOnOwningThread();
 
   mInputProcessing = new AudioInputProcessing(
     mDeviceMaxChannelCount, mStream, mTrackID, mPrincipal);
@@ -711,10 +691,7 @@ MediaEngineWebRTCMicrophoneSource::Stop(const RefPtr<const AllocationHandle>&)
     return NS_OK;
   }
 
-#ifdef MOZ_PULSEAUDIO
-  MOZ_ASSERT(sInputStreamsOpen > 0);
-  sInputStreamsOpen--;
-#endif
+
   RefPtr<MediaEngineWebRTCMicrophoneSource> that = this;
   RefPtr<MediaStreamGraphImpl> gripGraph = mStream->GraphImpl();
   NS_DispatchToMainThread(media::NewRunnableFrom(

modules/libpref/init/all.js

@@ -635,11 +635,6 @@ pref("media.audioipc.stack_size", 262144);
 pref("media.cubeb.sandbox", false);
 #endif
 
-#ifdef XP_LINUX
-// Bug 1481152
-pref("media.cubeb_max_input_streams", 1);
-#endif
-
 #ifdef MOZ_AV1
 pref("media.av1.enabled", false);
 #endif