Fix VirtualAudioInputStream callback timing issues.

content/renderer/media/audio_renderer_mixer_manager.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.
 
 #include "content/renderer/media/audio_renderer_mixer_manager.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/media/renderer_audio_output_device.h"
@@ skipping 36 matching lines @@
   base::AutoLock auto_lock(mixers_lock_);
 
   AudioRendererMixerMap::iterator it = mixers_.find(key);
   if (it != mixers_.end()) {
     it->second.ref_count++;
     return it->second.mixer;
   }
 
   // Create output parameters based on the audio hardware configuration for
   // passing on to the output sink.  Force to 16-bit output for now since we
-  // know that works well for WebAudio and WebRTC.
+  // know that works well for WebAudio and WebRTC. Force a 2048 buffer size
+  // until we have renderer-side device changes since WebRTC audio mirroring
+  // will use the input device's buffer size to drive mirroring so we need
+  // the output device's buffer size to be big enough.
   media::AudioParameters output_params(
       media::AudioParameters::AUDIO_PCM_LOW_LATENCY, params.channel_layout(),
-      hardware_sample_rate_, 16, hardware_buffer_size_);
+      hardware_sample_rate_, 16, 2048);

[DaleCurtis, 2013/01/15 21:00:08]

You'll need to test this on mac/win and make sure there are no issues with HTML5
audio/video. Specifically playback must continue to be smooth on say
http://xorax.sea/snowboard.mp4

[justinlin, 2013/01/15 22:36:21]

OK, will test.

 
   // If we've created invalid output parameters, simply pass on the input params
   // and let the browser side handle automatic fallback.
   if (!output_params.IsValid())
     output_params = params;
 
   media::AudioRendererMixer* mixer;
   if (sink_for_testing_) {
     mixer = new media::AudioRendererMixer(
         params, output_params, sink_for_testing_);
@@ skipping 20 matching lines @@
 
   // Only remove the mixer if AudioRendererMixerManager is the last owner.
   it->second.ref_count--;
   if (it->second.ref_count == 0) {
     delete it->second.mixer;
     mixers_.erase(it);
   }
 }
 
 }  // namespace content