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   DCHECK(mixers_.empty());
  25 }
  26
  27 media::AudioRendererMixerInput* AudioRendererMixerManager::CreateInput(
  28     int source_render_view_id, int source_render_frame_id) {
  29   return new media::AudioRendererMixerInput(
  30       base::Bind(
  31           &AudioRendererMixerManager::GetMixer, base::Unretained(this),
  32           source_render_view_id,
  33           source_render_frame_id),
  34       base::Bind(
  35           &AudioRendererMixerManager::RemoveMixer, base::Unretained(this),
  36           source_render_view_id));
  37 }
  38
  39 void AudioRendererMixerManager::SetAudioRendererSinkForTesting(
  40     media::AudioRendererSink* sink) {
  41   sink_for_testing_ = sink;
  42 }
  43
  44 media::AudioRendererMixer* AudioRendererMixerManager::GetMixer(
  45     int source_render_view_id,
  46     int source_render_frame_id,
  47     const media::AudioParameters& params) {
  48   const MixerKey key(source_render_view_id, params);
  49   base::AutoLock auto_lock(mixers_lock_);
  50
  51   AudioRendererMixerMap::iterator it = mixers_.find(key);
  52   if (it != mixers_.end()) {
  53     it->second.ref_count++;
  54     return it->second.mixer;
  55   }
  56
  57   // On ChromeOS and Linux we can rely on the playback device to handle
  58   // resampling, so don't waste cycles on it here.
  59 #if defined(OS_CHROMEOS) || defined(OS_LINUX)
  60   int sample_rate = params.sample_rate();
  61 #else
  62   int sample_rate = hardware_config_->GetOutputSampleRate();
  63 #endif
  64
  65   // Create output parameters based on the audio hardware configuration for
  66   // passing on to the output sink.  Force to 16-bit output for now since we
  67   // know that works well for WebAudio and WebRTC.
  68   media::AudioParameters output_params(
  69       media::AudioParameters::AUDIO_PCM_LOW_LATENCY, params.channel_layout(),
  70       sample_rate, 16, hardware_config_->GetHighLatencyBufferSize());
  71
  72   // If we've created invalid output parameters, simply pass on the input params
  73   // and let the browser side handle automatic fallback.
  74   if (!output_params.IsValid())
  75     output_params = params;
  76
  77   media::AudioRendererMixer* mixer;
  78   if (sink_for_testing_) {
  79     mixer = new media::AudioRendererMixer(
  80         params, output_params, sink_for_testing_);
  81   } else {
  82     mixer = new media::AudioRendererMixer(
  83         params, output_params, AudioDeviceFactory::NewOutputDevice(
  84             source_render_view_id, source_render_frame_id));
  85   }
  86
  87   AudioRendererMixerReference mixer_reference = { mixer, 1 };
  88   mixers_[key] = mixer_reference;
  89   return mixer;
  90 }
  91
  92 void AudioRendererMixerManager::RemoveMixer(
  93     int source_render_view_id,
  94     const media::AudioParameters& params) {
  95   const MixerKey key(source_render_view_id, params);
  96   base::AutoLock auto_lock(mixers_lock_);
  97
  98   AudioRendererMixerMap::iterator it = mixers_.find(key);
  99   DCHECK(it != mixers_.end());
 100
 101   // Only remove the mixer if AudioRendererMixerManager is the last owner.
 102   it->second.ref_count--;
 103   if (it->second.ref_count == 0) {
 104     delete it->second.mixer;
 105     mixers_.erase(it);
 106   }
 107 }
 108
 109 }  // namespace content