// 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. #ifndef CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_ #define CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_ #include <map> #include <utility> #include "base/synchronization/lock.h" #include "content/common/content_export.h" #include "media/audio/audio_parameters.h" namespace media { class AudioHardwareConfig; class AudioRendererMixer; class AudioRendererMixerInput; class AudioRendererSink; } namespace content { // Manages sharing of an AudioRendererMixer among AudioRendererMixerInputs based // on their AudioParameters configuration. Inputs with the same AudioParameters // configuration will share a mixer while a new AudioRendererMixer will be // lazily created if one with the exact AudioParameters does not exist. // // There should only be one instance of AudioRendererMixerManager per render // thread. // // TODO(dalecurtis): Right now we require AudioParameters to be an exact match // when we should be able to ignore bits per channel since we're only dealing // with floats. However, bits per channel is currently used to interleave the // audio data by AudioOutputDevice::AudioThreadCallback::Process for consumption // via the shared memory. See http://crbug.com/114700. class CONTENT_EXPORT AudioRendererMixerManager { public: // Construct an instance using the given audio hardware configuration. The // provided |hardware_config| is not owned by AudioRendererMixerManager and // must outlive it. explicit AudioRendererMixerManager( media::AudioHardwareConfig* hardware_config); ~AudioRendererMixerManager(); // Creates an AudioRendererMixerInput with the proper callbacks necessary to // retrieve an AudioRendererMixer instance from AudioRendererMixerManager. // |source_render_view_id| refers to the RenderView containing the entity // rendering the audio. |source_render_frame_id| refers to the RenderFrame // containing the entity rendering the audio. Caller must ensure // AudioRendererMixerManager outlives the returned input. media::AudioRendererMixerInput* CreateInput(int source_render_view_id, int source_render_frame_id); // Returns a mixer instance based on AudioParameters; an existing one if one // with the provided AudioParameters exists or a new one if not. media::AudioRendererMixer* GetMixer(int source_render_view_id, int source_render_frame_id, const media::AudioParameters& params); // Remove a mixer instance given a mixer if the only other reference is held // by AudioRendererMixerManager. Every AudioRendererMixer owner must call // this method when it's done with a mixer. void RemoveMixer(int source_render_view_id, const media::AudioParameters& params); private: friend class AudioRendererMixerManagerTest; // Define a key so that only those AudioRendererMixerInputs from the same // RenderView and with the same AudioParameters can be mixed together. typedef std::pair<int, media::AudioParameters> MixerKey; // Map of MixerKey to <AudioRendererMixer, Count>. Count allows // AudioRendererMixerManager to keep track explicitly (v.s. RefCounted which // is implicit) of the number of outstanding AudioRendererMixers. struct AudioRendererMixerReference { media::AudioRendererMixer* mixer; int ref_count; }; typedef std::map<MixerKey, AudioRendererMixerReference> AudioRendererMixerMap; // Overrides the AudioRendererSink implementation for unit testing. void SetAudioRendererSinkForTesting(media::AudioRendererSink* sink); // Active mixers. AudioRendererMixerMap mixers_; base::Lock mixers_lock_; // Audio hardware configuration. Used to construct output AudioParameters for // each AudioRendererMixer instance. media::AudioHardwareConfig* const hardware_config_; media::AudioRendererSink* sink_for_testing_; DISALLOW_COPY_AND_ASSIGN(AudioRendererMixerManager); }; } // namespace content #endif // CONTENT_RENDERER_MEDIA_AUDIO_RENDERER_MIXER_MANAGER_H_