Pass more detailed audio hardware configuration information to the renderer

media/audio/audio_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Software adjust volume of samples, allows each audio stream its own
 // volume without impacting master volume for chrome and other applications.
 
 // Implemented as templates to allow 8, 16 and 32 bit implementations.
 // 8 bit is unsigned and biased by 128.
 
@@ skipping 11 matching lines @@
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/time.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/audio_bus.h"
 #include "media/base/media_switches.h"
 
 #if defined(OS_MACOSX)
 #include "media/audio/mac/audio_low_latency_input_mac.h"
 #include "media/audio/mac/audio_low_latency_output_mac.h"
+#include "media/audio/mac/audio_unified_mac.h"
 #elif defined(OS_WIN)
 #include "base/win/windows_version.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/win/audio_low_latency_input_win.h"
 #include "media/audio/win/audio_low_latency_output_win.h"
 #include "media/audio/win/core_audio_util_win.h"
 #include "media/base/limits.h"
 #endif
 
 namespace media {
@@ skipping 235 matching lines @@
   //  - The entire Windows audio stack was rewritten for Windows Vista and wave
   //    out performance was degraded compared to XP.
   //  - The regression was fixed in Windows 7 and most configurations will work
   //    with 2, but some (e.g., some Sound Blasters) still need 3.
   //  - Some XP configurations (even multi-processor ones) also need 3.
   return (base::win::GetVersion() == base::win::VERSION_VISTA) ? 4 : 3;
 }
 
 #endif
 
+int GetAudioHardwareOutputChannels() {
+#if defined(OS_MACOSX)
+  int channels, channels_per_frame;
+  if (AudioHardwareUnifiedStream::GetDefaultOutputChannels(
+      &channels, &channels_per_frame))
+    return channels;
+  else
+    return 2;
+#else
+  // !!!!
+  return 2;
+#endif
+}
+
 }  // namespace media