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 #ifndef MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_ 6 #define MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_ 7 8 #include <map> 9 #include <set> 10 11 #include "base/gtest_prod_util.h" 12 #include "base/memory/scoped_ptr.h" 13 #include "base/synchronization/lock.h" 14 #include "base/threading/thread_checker.h" 15 #include "media/audio/audio_io.h" 16 #include "media/audio/audio_parameters.h" 17 #include "media/audio/fake_audio_consumer.h" 18 #include "media/base/audio_converter.h" 19 20 namespace base { 21 class SingleThreadTaskRunner; 22 } 23 24 namespace media { 25 26 class LoopbackAudioConverter; 27 class VirtualAudioOutputStream; 28 29 // VirtualAudioInputStream converts and mixes audio from attached 30 // VirtualAudioOutputStreams into a single stream. It will continuously render 31 // audio until this VirtualAudioInputStream is stopped and closed. 32 class MEDIA_EXPORT VirtualAudioInputStream : public AudioInputStream { 33 public: 34 // Callback invoked just after VirtualAudioInputStream is closed. 35 typedef base::Callback<void(VirtualAudioInputStream* vais)> 36 AfterCloseCallback; 37 38 // Construct a target for audio loopback which mixes multiple data streams 39 // into a single stream having the given |params|. |worker_task_runner| is 40 // the task runner on which AudioInputCallback methods are called and may or 41 // may not be the single thread that invokes the AudioInputStream methods. 42 VirtualAudioInputStream( 43 const AudioParameters& params, 44 const scoped_refptr<base::SingleThreadTaskRunner>& worker_task_runner, 45 const AfterCloseCallback& after_close_cb); 46 47 virtual ~VirtualAudioInputStream(); 48 49 // AudioInputStream: 50 virtual bool Open() OVERRIDE; 51 virtual void Start(AudioInputCallback* callback) OVERRIDE; 52 virtual void Stop() OVERRIDE; 53 virtual void Close() OVERRIDE; 54 virtual double GetMaxVolume() OVERRIDE; 55 virtual void SetVolume(double volume) OVERRIDE; 56 virtual double GetVolume() OVERRIDE; 57 virtual void SetAutomaticGainControl(bool enabled) OVERRIDE; 58 virtual bool GetAutomaticGainControl() OVERRIDE; 59 virtual bool IsMuted() OVERRIDE; 60 61 // Attaches a VirtualAudioOutputStream to be used as input. This 62 // VirtualAudioInputStream must outlive all attached streams, so any attached 63 // stream must be closed (which causes a detach) before 64 // VirtualAudioInputStream is destroyed. 65 virtual void AddOutputStream(VirtualAudioOutputStream* stream, 66 const AudioParameters& output_params); 67 68 // Detaches a VirtualAudioOutputStream and removes it as input. 69 virtual void RemoveOutputStream(VirtualAudioOutputStream* stream, 70 const AudioParameters& output_params); 71 72 private: 73 friend class VirtualAudioInputStreamTest; 74 75 typedef std::map<AudioParameters, LoopbackAudioConverter*> AudioConvertersMap; 76 77 // Pulls audio data from all attached VirtualAudioOutputStreams, mixes and 78 // converts the streams into one, and pushes the result to |callback_|. 79 // Invoked on the worker thread. 80 void PumpAudio(AudioBus* audio_bus); 81 82 const scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner_; 83 84 AfterCloseCallback after_close_cb_; 85 86 AudioInputCallback* callback_; 87 88 // Non-const for testing. 89 scoped_ptr<uint8[]> buffer_; 90 AudioParameters params_; 91 92 // Guards concurrent access to the converter network: converters_, mixer_, and 93 // num_attached_output_streams_. 94 base::Lock converter_network_lock_; 95 96 // AudioConverters associated with the attached VirtualAudioOutputStreams, 97 // partitioned by common AudioParameters. 98 AudioConvertersMap converters_; 99 100 // AudioConverter that takes all the audio converters and mixes them into one 101 // final audio stream. 102 AudioConverter mixer_; 103 104 // Number of currently attached VirtualAudioOutputStreams. 105 int num_attached_output_streams_; 106 107 // Handles callback timing for consumption of audio data. 108 FakeAudioConsumer fake_consumer_; 109 110 base::ThreadChecker thread_checker_; 111 112 DISALLOW_COPY_AND_ASSIGN(VirtualAudioInputStream); 113 }; 114 115 } // namespace media 116 117 #endif // MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_ 118