Browser-wide audio mirroring for TabCapture API

media/audio/audio_manager_base.cc

Index: media/audio/audio_manager_base.cc
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index 7b79613774c2b66ad3031794daf7810f894a1ddf..b5b86603417196f695eedb47ecd85f880a2f1a37 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop_proxy.h"
+#include "base/string_util.h"
 #include "base/threading/thread.h"
 #include "media/audio/audio_output_dispatcher_impl.h"
 #include "media/audio/audio_output_proxy.h"
@@ -14,6 +15,8 @@
 #include "media/audio/audio_util.h"
 #include "media/audio/fake_audio_input_stream.h"
 #include "media/audio/fake_audio_output_stream.h"
+#include "media/audio/virtual_audio_input_stream.h"
+#include "media/audio/virtual_audio_output_stream.h"
 #include "media/base/media_switches.h"
 
 // TODO(dalecurtis): Temporarily disabled while switching pipeline to use float,
@@ -100,6 +103,18 @@ AudioOutputStream* AudioManagerBase::MakeAudioOutputStream(
       !HasAudioOutputDevices();
 
   AudioOutputStream* stream = NULL;
+
+  // Temp hack to use virtual device for everything except webRTC output.
+  bool use_virtual_device = params.sample_rate() != 48000;
+
+  if (use_virtual_device) {
+    stream = VirtualAudioOutputStream::MakeStream(this, params);
+    audio_thread_->message_loop()->PostTask(FROM_HERE, base::Bind(

[DaleCurtis, 2012/11/07 23:34:17]

I believe this is already on the audio thread, no?

[justinlin, 2012/11/20 08:56:10]

Done.

+        &AudioManagerBase::RegisterVirtualAudioOutputStream,
+        base::Unretained(this), stream));
+    return stream;
+  }
+
   if (audio_output_disabled) {
     stream = FakeAudioOutputStream::MakeFakeStream(this, params);
   } else if (params.format() == AudioParameters::AUDIO_PCM_LINEAR) {
@@ -108,12 +123,24 @@ AudioOutputStream* AudioManagerBase::MakeAudioOutputStream(
     stream = MakeLowLatencyOutputStream(params);
   }
 
-  if (stream)
-    ++num_output_streams_;
-
   return stream;
 }
 
+void AudioManagerBase::RegisterVirtualAudioOutputStream(
+    AudioOutputStream* stream) {
+  virtual_audio_output_streams_.insert(stream);
+}
+
+void AudioManagerBase::UnregisterVirtualAudioOutputStream(
+    AudioOutputStream* stream) {
+  virtual_audio_output_streams_.erase(stream);
+}
+
+AudioManagerBase::AudioOutputStreamList
+    AudioManagerBase::GetVirtualAudioOutputStreams() {
+  return virtual_audio_output_streams_;
+}
+
 AudioInputStream* AudioManagerBase::MakeAudioInputStream(
     const AudioParameters& params, const std::string& device_id) {
   if (!params.IsValid() || (params.channels() > kMaxInputChannels) ||
@@ -129,8 +156,14 @@ AudioInputStream* AudioManagerBase::MakeAudioInputStream(
     return NULL;
   }
 
+  // TODO(justinlin): Bah! Linking issues with content::, fix this later.
+  const std::string kMediaStreamTabDeviceScheme = "virtual://";
+
   AudioInputStream* stream = NULL;
-  if (params.format() == AudioParameters::AUDIO_FAKE) {
+  if (StartsWithASCII(device_id,
+                      kMediaStreamTabDeviceScheme, true)) {
+    stream = VirtualAudioInputStream::MakeStream(this, params);
+  } else if (params.format() == AudioParameters::AUDIO_FAKE) {
     stream = FakeAudioInputStream::MakeFakeStream(this, params);
   } else if (params.format() == AudioParameters::AUDIO_PCM_LINEAR) {
     stream = MakeLinearInputStream(params, device_id);
@@ -237,6 +270,11 @@ void AudioManagerBase::ReleaseOutputStream(AudioOutputStream* stream) {
   // TODO(xians) : Have a clearer destruction path for the AudioOutputStream.
   // For example, pass the ownership to AudioManager so it can delete the
   // streams.
+
+  audio_thread_->message_loop()->PostTask(FROM_HERE, base::Bind(

[DaleCurtis, 2012/11/07 23:34:17]

Ditto.

[justinlin, 2012/11/20 08:56:10]

Done.

+      &AudioManagerBase::UnregisterVirtualAudioOutputStream,
+      base::Unretained(this), stream));
+
   num_output_streams_--;
   delete stream;
 }