content/renderer/media/audio_renderer_mixer_manager.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/renderer/media/audio_renderer_mixer_manager.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "content/renderer/media/audio_device_factory.h"
  10 #include "media/audio/audio_output_device.h"
  11 #include "media/base/audio_hardware_config.h"
  12 #include "media/base/audio_renderer_mixer.h"
  13 #include "media/base/audio_renderer_mixer_input.h"
  14
  15 namespace content {
  16
  17 AudioRendererMixerManager::AudioRendererMixerManager(
  18     media::AudioHardwareConfig* hardware_config)
  19     : hardware_config_(hardware_config),
  20       sink_for_testing_(NULL) {
  21 }
  22
  23 AudioRendererMixerManager::~AudioRendererMixerManager() {
  24   // References to AudioRendererMixers may be owned by garbage collected
  25   // objects.  During process shutdown they may be leaked, so, transitively,
  26   // |mixers_| may leak (i.e., may be non-empty at this time) as well.
  27 }
  28
  29 media::AudioRendererMixerInput* AudioRendererMixerManager::CreateInput(
  30     int source_render_view_id, int source_render_frame_id) {
  31   return new media::AudioRendererMixerInput(
  32       base::Bind(
  33           &AudioRendererMixerManager::GetMixer, base::Unretained(this),
  34           source_render_view_id,
  35           source_render_frame_id),
  36       base::Bind(
  37           &AudioRendererMixerManager::RemoveMixer, base::Unretained(this),
  38           source_render_view_id));
  39 }
  40
  41 void AudioRendererMixerManager::SetAudioRendererSinkForTesting(
  42     media::AudioRendererSink* sink) {
  43   sink_for_testing_ = sink;
  44 }
  45
  46 media::AudioRendererMixer* AudioRendererMixerManager::GetMixer(
  47     int source_render_view_id,
  48     int source_render_frame_id,
  49     const media::AudioParameters& params) {
  50   // Effects are not passed through to output creation, so ensure none are set.
  51   DCHECK_EQ(params.effects(), media::AudioParameters::NO_EFFECTS);
  52
  53   const MixerKey key(source_render_view_id, params);
  54   base::AutoLock auto_lock(mixers_lock_);
  55
  56   AudioRendererMixerMap::iterator it = mixers_.find(key);
  57   if (it != mixers_.end()) {
  58     it->second.ref_count++;
  59     return it->second.mixer;
  60   }
  61
  62   // On ChromeOS we can rely on the playback device to handle resampling, so
  63   // don't waste cycles on it here.
  64 #if defined(OS_CHROMEOS)
  65   int sample_rate = params.sample_rate();
  66 #else
  67   int sample_rate = hardware_config_->GetOutputSampleRate();
  68 #endif
  69
  70   // Create output parameters based on the audio hardware configuration for
  71   // passing on to the output sink.  Force to 16-bit output for now since we
  72   // know that works everywhere; ChromeOS does not support other bit depths.
  73   media::AudioParameters output_params(
  74       media::AudioParameters::AUDIO_PCM_LOW_LATENCY, params.channel_layout(),
  75       sample_rate, 16, hardware_config_->GetHighLatencyBufferSize());
  76
  77   // If we've created invalid output parameters, simply pass on the input params
  78   // and let the browser side handle automatic fallback.
  79   if (!output_params.IsValid())
  80     output_params = params;
  81
  82   media::AudioRendererMixer* mixer;
  83   if (sink_for_testing_) {
  84     mixer = new media::AudioRendererMixer(
  85         params, output_params, sink_for_testing_);
  86   } else {
  87     mixer = new media::AudioRendererMixer(
  88         params, output_params, AudioDeviceFactory::NewOutputDevice(
  89             source_render_view_id, source_render_frame_id));
  90   }
  91
  92   AudioRendererMixerReference mixer_reference = { mixer, 1 };
  93   mixers_[key] = mixer_reference;
  94   return mixer;
  95 }
  96
  97 void AudioRendererMixerManager::RemoveMixer(
  98     int source_render_view_id,
  99     const media::AudioParameters& params) {
 100   const MixerKey key(source_render_view_id, params);
 101   base::AutoLock auto_lock(mixers_lock_);
 102
 103   AudioRendererMixerMap::iterator it = mixers_.find(key);
 104   DCHECK(it != mixers_.end());
 105
 106   // Only remove the mixer if AudioRendererMixerManager is the last owner.
 107   it->second.ref_count--;
 108   if (it->second.ref_count == 0) {
 109     delete it->second.mixer;
 110     mixers_.erase(it);
 111   }
 112 }
 113
 114 }  // namespace content