| // 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 MEDIA_BASE_AUDIO_RENDERER_MIXER_H_ |
| #define MEDIA_BASE_AUDIO_RENDERER_MIXER_H_ |
| |
| #include <stdint.h> |
| |
| #include <map> |
| #include <memory> |
| #include <string> |
| |
| #include "base/macros.h" |
| #include "base/synchronization/lock.h" |
| #include "base/time/time.h" |
| #include "media/base/audio_converter.h" |
| #include "media/base/audio_renderer_sink.h" |
| #include "media/base/loopback_audio_converter.h" |
| |
| namespace media { |
| |
| // Mixes a set of AudioConverter::InputCallbacks into a single output stream |
| // which is funneled into a single shared AudioRendererSink; saving a bundle |
| // on renderer side resources. |
| class MEDIA_EXPORT AudioRendererMixer |
| : NON_EXPORTED_BASE(public AudioRendererSink::RenderCallback) { |
| public: |
| AudioRendererMixer(const AudioParameters& output_params, |
| scoped_refptr<AudioRendererSink> sink); |
| ~AudioRendererMixer() override; |
| |
| // Add or remove a mixer input from mixing; called by AudioRendererMixerInput. |
| void AddMixerInput(const AudioParameters& input_params, |
| AudioConverter::InputCallback* input); |
| void RemoveMixerInput(const AudioParameters& input_params, |
| AudioConverter::InputCallback* input); |
| |
| // Since errors may occur even when no inputs are playing, an error callback |
| // must be registered separately from adding a mixer input. The same callback |
| // must be given to both the functions. |
| void AddErrorCallback(const base::Closure& error_cb); |
| void RemoveErrorCallback(const base::Closure& error_cb); |
| |
| void set_pause_delay_for_testing(base::TimeDelta delay) { |
| pause_delay_ = delay; |
| } |
| |
| OutputDeviceInfo GetOutputDeviceInfo(); |
| |
| private: |
| // Maps input sample rate to the dedicated converter. |
| using AudioConvertersMap = |
| std::map<int, std::unique_ptr<LoopbackAudioConverter>>; |
| |
| // AudioRendererSink::RenderCallback implementation. |
| int Render(AudioBus* audio_bus, |
| uint32_t frames_delayed, |
| uint32_t frames_skipped) override; |
| void OnRenderError() override; |
| |
| bool is_master_sample_rate(int sample_rate) { |
| return sample_rate == output_params_.sample_rate(); |
| } |
| |
| // Output parameters for this mixer. |
| const AudioParameters output_params_; |
| |
| // Output sink for this mixer. |
| const scoped_refptr<AudioRendererSink> audio_sink_; |
| |
| // ---------------[ All variables below protected by |lock_| ]--------------- |
| base::Lock lock_; |
| |
| // List of error callbacks used by this mixer. |
| typedef std::list<base::Closure> ErrorCallbackList; |
| ErrorCallbackList error_callbacks_; |
| |
| // Each of these converters mixes inputs with a given sample rate and |
| // resamples them to the output sample rate. Inputs not reqiuring resampling |
| // go directly to |master_converter_|. |
| AudioConvertersMap converters_; |
| |
| // Master converter which mixes all the outputs from |converters_| as well as |
| // mixer inputs that are in the output sample rate. |
| AudioConverter master_converter_; |
| |
| // Handles physical stream pause when no inputs are playing. For latency |
| // reasons we don't want to immediately pause the physical stream. |
| base::TimeDelta pause_delay_; |
| base::TimeTicks last_play_time_; |
| bool playing_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AudioRendererMixer); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_AUDIO_RENDERER_MIXER_H_ |