From 32d217338fc1e1ee1a4e6660f64c3495e52db86c Mon Sep 17 00:00:00 2001
From: Paul Adenot <paul@paul.cx>
Date: Tue, 12 May 2020 08:31:58 +0000
Subject: [PATCH] Bug 1626081 - Add a pref to disable the audio output stream
 routing on Android. r=achronop

Differential Revision: https://phabricator.services.mozilla.com/D74274
---
 dom/media/CubebUtils.cpp    | 11 +++++++++++
 dom/media/CubebUtils.h      |  4 ++++
 dom/media/GraphDriver.cpp   |  7 ++++++-
 modules/libpref/init/all.js |  2 ++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/dom/media/CubebUtils.cpp b/dom/media/CubebUtils.cpp
index 36d7680e415e..509eab885346 100644
--- a/dom/media/CubebUtils.cpp
+++ b/dom/media/CubebUtils.cpp
@@ -52,6 +52,7 @@
 #define PREF_CUBEB_LOGGING_LEVEL "media.cubeb.logging_level"
 // Hidden pref used by tests to force failure to obtain cubeb context
 #define PREF_CUBEB_FORCE_NULL_CONTEXT "media.cubeb.force_null_context"
+#define PREF_CUBEB_OUTPUT_VOICE_ROUTING "media.cubeb.output_voice_routing"
 // Hidden pref to disable BMO 1427011 experiment; can be removed once proven.
 #define PREF_CUBEB_DISABLE_DEVICE_SWITCHING \
   "media.cubeb.disable_device_switching"
@@ -100,6 +101,7 @@ bool sCubebMTGLatencyPrefSet = false;
 bool sAudioStreamInitEverSucceeded = false;
 bool sCubebForceNullContext = false;
 bool sCubebDisableDeviceSwitching = true;
+bool sRouteOutputAsVoice = false;
 #ifdef MOZ_CUBEB_REMOTING
 bool sCubebSandbox = false;
 size_t sAudioIPCPoolSize;
@@ -267,6 +269,13 @@ void PrefChanged(const char* aPref, void* aClosure) {
                                               AUDIOIPC_STACK_SIZE_DEFAULT);
   }
 #endif
+  else if (strcmp(aPref, PREF_CUBEB_OUTPUT_VOICE_ROUTING) == 0) {
+    StaticMutexAutoLock lock(sMutex);
+    sRouteOutputAsVoice = Preferences::GetBool(aPref);
+    MOZ_LOG(gCubebLog, LogLevel::Verbose,
+            ("%s: %s", PREF_CUBEB_OUTPUT_VOICE_ROUTING,
+             sRouteOutputAsVoice ? "true" : "false"));
+  }
 }
 
 bool GetFirstStream() {
@@ -676,6 +685,8 @@ cubeb_stream_prefs GetDefaultStreamPrefs() {
   return CUBEB_STREAM_PREF_NONE;
 }
 
+bool RouteOutputAsVoice() { return sRouteOutputAsVoice; }
+
 #ifdef MOZ_WIDGET_ANDROID
 uint32_t AndroidGetAudioOutputSampleRate() {
   int32_t sample_rate = java::GeckoAppShell::GetAudioOutputSampleRate();
diff --git a/dom/media/CubebUtils.h b/dom/media/CubebUtils.h
index 1affdc7f96a3..fd0de084ea1b 100644
--- a/dom/media/CubebUtils.h
+++ b/dom/media/CubebUtils.h
@@ -51,6 +51,10 @@ char* GetForcedOutputDevice();
 // to switch to "communication mode", which might change audio routing,
 // bluetooth communication type, etc.
 void SetInCommunication(bool aInCommunication);
+// Returns true if the output streams should be routed like a stream containing
+// voice data, and not generic audio. This can influence audio processing and
+// device selection.
+bool RouteOutputAsVoice();
 
 #  ifdef MOZ_WIDGET_ANDROID
 uint32_t AndroidGetAudioOutputSampleRate();
diff --git a/dom/media/GraphDriver.cpp b/dom/media/GraphDriver.cpp
index a7cfb2744f32..07d2a6ddcaa6 100644
--- a/dom/media/GraphDriver.cpp
+++ b/dom/media/GraphDriver.cpp
@@ -642,7 +642,8 @@ void AudioCallbackDriver::Init() {
   output.layout = static_cast<uint32_t>(channelMap);
   output.prefs = CubebUtils::GetDefaultStreamPrefs();
 #if !defined(XP_WIN)
-  if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE) {
+  if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE &&
+      CubebUtils::RouteOutputAsVoice()) {
     output.prefs |= static_cast<cubeb_stream_prefs>(CUBEB_STREAM_PREF_VOICE);
   }
 #endif
@@ -671,6 +672,10 @@ void AudioCallbackDriver::Init() {
   input = output;
   input.channels = mInputChannelCount;
   input.layout = CUBEB_LAYOUT_UNDEFINED;
+  input.prefs = CubebUtils::GetDefaultStreamPrefs();
+  if (mInputDevicePreference == CUBEB_DEVICE_PREF_VOICE) {
+    input.prefs |= static_cast<cubeb_stream_prefs>(CUBEB_STREAM_PREF_VOICE);
+  }
 
   cubeb_stream* stream = nullptr;
   bool inputWanted = mInputChannelCount > 0;
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 96b357301626..cd34d77d16c5 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -583,6 +583,8 @@ pref("media.cubeb.logging_level", "");
   pref("media.cubeb.backend", "audiounit-rust");
 #endif
 
+pref("media.cubeb.output_voice_routing", true);
+
 // GraphRunner (fixed MediaTrackGraph thread) control
 pref("media.audiograph.single_thread.enabled", true);