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