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.
5 #ifndef MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_
6 #define MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_
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"
21 class SingleThreadTaskRunner;
26 class LoopbackAudioConverter;
27 class VirtualAudioOutputStream;
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 {
34 // Callback invoked just after VirtualAudioInputStream is closed.
35 typedef base::Callback<void(VirtualAudioInputStream* vais)>
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);
47 virtual ~VirtualAudioInputStream();
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;
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);
68 // Detaches a VirtualAudioOutputStream and removes it as input.
69 virtual void RemoveOutputStream(VirtualAudioOutputStream* stream,
70 const AudioParameters& output_params);
73 friend class VirtualAudioInputStreamTest;
75 typedef std::map<AudioParameters, LoopbackAudioConverter*> AudioConvertersMap;
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);
82 const scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner_;
84 AfterCloseCallback after_close_cb_;
86 AudioInputCallback* callback_;
88 // Non-const for testing.
89 scoped_ptr<uint8[]> buffer_;
90 AudioParameters params_;
92 // Guards concurrent access to the converter network: converters_, mixer_, and
93 // num_attached_output_streams_.
94 base::Lock converter_network_lock_;
96 // AudioConverters associated with the attached VirtualAudioOutputStreams,
97 // partitioned by common AudioParameters.
98 AudioConvertersMap converters_;
100 // AudioConverter that takes all the audio converters and mixes them into one
101 // final audio stream.
102 AudioConverter mixer_;
104 // Number of currently attached VirtualAudioOutputStreams.
105 int num_attached_output_streams_;
107 // Handles callback timing for consumption of audio data.
108 FakeAudioConsumer fake_consumer_;
110 base::ThreadChecker thread_checker_;
112 DISALLOW_COPY_AND_ASSIGN(VirtualAudioInputStream);
117 #endif // MEDIA_AUDIO_VIRTUAL_AUDIO_INPUT_STREAM_H_