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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 // | 4 // |
5 // Creates an audio output stream based on the PulseAudio asynchronous API. | 5 // Creates an audio output stream based on the PulseAudio asynchronous API; |
| 6 // specifically using the pa_threaded_mainloop model. |
6 // | 7 // |
7 // If the stream is successfully opened, Close() must be called before the | 8 // If the stream is successfully opened, Close() must be called before the |
8 // stream is deleted as Close() is responsible for ensuring resource cleanup | 9 // stream is deleted as Close() is responsible for ensuring resource cleanup |
9 // occurs. | 10 // occurs. |
10 // | 11 // |
11 // This object is designed so that all AudioOutputStream methods will be called | 12 // This object is designed so that all AudioOutputStream methods will be called |
12 // on the same thread that created the object. | 13 // on the same thread that created the object. |
13 // | 14 // |
14 // WARNING: This object blocks on internal PulseAudio calls in Open() while | 15 // WARNING: This object blocks on internal PulseAudio calls in Open() while |
15 // waiting for PulseAudio's context structure to be ready. It also blocks in | 16 // waiting for PulseAudio's context structure to be ready. It also blocks in |
16 // inside PulseAudio in Start() and repeated during playback, waiting for | 17 // inside PulseAudio in Start() and repeated during playback, waiting for |
17 // PulseAudio write callbacks to occur. | 18 // PulseAudio write callbacks to occur. |
18 | 19 |
19 #ifndef MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ | 20 #ifndef MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ |
20 #define MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ | 21 #define MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ |
21 | 22 |
22 #include <pulse/pulseaudio.h> | 23 #include "base/memory/scoped_ptr.h" |
| 24 #include "media/audio/audio_io.h" |
| 25 #include "media/audio/audio_parameters.h" |
23 | 26 |
24 #include "base/memory/scoped_ptr.h" | 27 struct pa_context; |
25 #include "base/memory/weak_ptr.h" | 28 struct pa_operation; |
26 #include "media/audio/audio_io.h" | 29 struct pa_stream; |
27 #include "media/base/channel_layout.h" | 30 struct pa_threaded_mainloop; |
28 | 31 |
29 namespace media { | 32 namespace media { |
30 | 33 class AudioManagerBase; |
31 #if defined(OS_LINUX) | |
32 class AudioManagerLinux; | |
33 typedef AudioManagerLinux AudioManagerPulse; | |
34 #elif defined(OS_OPENBSD) | |
35 class AudioManagerOpenBSD; | |
36 typedef AudioManagerOpenBSD AudioManagerPulse; | |
37 #else | |
38 #error Unsupported platform | |
39 #endif | |
40 | |
41 class AudioParameters; | |
42 class SeekableBuffer; | |
43 | 34 |
44 class PulseAudioOutputStream : public AudioOutputStream { | 35 class PulseAudioOutputStream : public AudioOutputStream { |
45 public: | 36 public: |
46 PulseAudioOutputStream(const AudioParameters& params, | 37 PulseAudioOutputStream(const AudioParameters& params, |
47 AudioManagerPulse* manager); | 38 AudioManagerBase* manager); |
48 | 39 |
49 virtual ~PulseAudioOutputStream(); | 40 virtual ~PulseAudioOutputStream(); |
50 | 41 |
51 // Implementation of AudioOutputStream. | 42 // Implementation of AudioOutputStream. |
52 virtual bool Open() OVERRIDE; | 43 virtual bool Open() OVERRIDE; |
53 virtual void Close() OVERRIDE; | 44 virtual void Close() OVERRIDE; |
54 virtual void Start(AudioSourceCallback* callback) OVERRIDE; | 45 virtual void Start(AudioSourceCallback* callback) OVERRIDE; |
55 virtual void Stop() OVERRIDE; | 46 virtual void Stop() OVERRIDE; |
56 virtual void SetVolume(double volume) OVERRIDE; | 47 virtual void SetVolume(double volume) OVERRIDE; |
57 virtual void GetVolume(double* volume) OVERRIDE; | 48 virtual void GetVolume(double* volume) OVERRIDE; |
58 | 49 |
59 private: | 50 private: |
60 // PulseAudio Callbacks. | 51 // Called by PulseAudio when |pa_context_| and |pa_stream_| change state. If |
61 static void ContextStateCallback(pa_context* context, void* state_addr); | 52 // an unexpected failure state change happens and |source_callback_| is set |
62 static void WriteRequestCallback(pa_stream* playback_handle, size_t length, | 53 // these methods will forward the error via OnError(). |
63 void* stream_addr); | 54 static void ContextNotifyCallback(pa_context* c, void* p_this); |
| 55 static void StreamNotifyCallback(pa_stream* s, void* p_this); |
64 | 56 |
65 // Iterate the PulseAudio mainloop to get write requests. | 57 // Triggers pa_threaded_mainloop_signal() to avoid deadlocks. |
66 void WaitForWriteRequest(); | 58 static void StreamSuccessCallback(pa_stream* s, int success, void* p_this); |
67 | 59 |
68 // Get another packet from the data source and write it to the client buffer. | 60 // Called by PulseAudio when it needs more audio data. |
69 bool BufferPacketFromSource(); | 61 static void StreamRequestCallback(pa_stream* s, size_t len, void* p_this); |
70 | 62 |
71 // Fulfill a write request from the write request callback. If the write | 63 // Fulfill a write request from the write request callback. Outputs silence |
72 // can't be finished a first, post a new attempt to the message loop. | 64 // if the request could not be fulfilled. |
73 void FulfillWriteRequest(size_t requested_bytes); | 65 void FulfillWriteRequest(size_t requested_bytes); |
74 | 66 |
75 // Write data from the client buffer to the PulseAudio stream. | |
76 void WriteToStream(size_t bytes_to_write, size_t* bytes_written); | |
77 | |
78 // API for Proxying calls to the AudioSourceCallback provided during Start(). | |
79 int RunDataCallback(AudioBus* audio_bus, AudioBuffersState buffers_state); | |
80 | |
81 // Close() helper function to free internal structs. | 67 // Close() helper function to free internal structs. |
82 void Reset(); | 68 void Reset(); |
83 | 69 |
84 // Configuration constants from the constructor. Referencable by all threads | 70 // Returns the current hardware latency value in bytes. |
85 // since they are constants. | 71 int GetHardwareLatencyInBytes(); |
86 const ChannelLayout channel_layout_; | 72 |
87 const uint32 channel_count_; | 73 // Helper method for waiting on Pulse Audio operations to complete. |
88 const pa_sample_format_t sample_format_; | 74 void WaitForPulseOperation(pa_operation* op); |
89 const uint32 sample_rate_; | 75 |
90 const uint32 bytes_per_frame_; | 76 // AudioParameters from the constructor. |
| 77 const AudioParameters params_; |
91 | 78 |
92 // Audio manager that created us. Used to report that we've closed. | 79 // Audio manager that created us. Used to report that we've closed. |
93 AudioManagerPulse* manager_; | 80 AudioManagerBase* manager_; |
94 | 81 |
95 // PulseAudio API structs. | 82 // PulseAudio API structs. |
96 pa_context* pa_context_; | 83 pa_context* pa_context_; |
97 pa_mainloop* pa_mainloop_; | 84 pa_threaded_mainloop* pa_mainloop_; |
98 | 85 pa_stream* pa_stream_; |
99 // Handle to the actual PulseAudio playback stream. | |
100 pa_stream* playback_handle_; | |
101 | |
102 // Device configuration data. Populated after Open() completes. | |
103 uint32 packet_size_; | |
104 uint32 frames_per_packet_; | |
105 | |
106 // Client side audio buffer feeding pulse audio's server side buffer. | |
107 scoped_ptr<media::SeekableBuffer> client_buffer_; | |
108 | 86 |
109 // Float representation of volume from 0.0 to 1.0. | 87 // Float representation of volume from 0.0 to 1.0. |
110 float volume_; | 88 float volume_; |
111 | 89 |
112 // Flag indicating the code should stop reading from the data source or | 90 // Callback to audio data source. Must only be modified while holding a lock |
113 // writing to the PulseAudio server. This is set because the device has | 91 // on |pa_mainloop_| via pa_threaded_mainloop_lock(). |
114 // entered an unrecoverable error state, or the Close() has executed. | |
115 bool stream_stopped_; | |
116 | |
117 // Whether or not PulseAudio has called the WriteCallback for the most recent | |
118 // set of pa_mainloop iterations. | |
119 bool write_callback_handled_; | |
120 | |
121 // Allows us to run tasks on the PulseAudioOutputStream instance which are | |
122 // bound by its lifetime. | |
123 base::WeakPtrFactory<PulseAudioOutputStream> weak_factory_; | |
124 | |
125 // Callback to audio data source. | |
126 AudioSourceCallback* source_callback_; | 92 AudioSourceCallback* source_callback_; |
127 | 93 |
128 // Container for retrieving data from AudioSourceCallback::OnMoreData(). | 94 // Container for retrieving data from AudioSourceCallback::OnMoreData(). |
129 scoped_ptr<AudioBus> audio_bus_; | 95 scoped_ptr<AudioBus> audio_bus_; |
130 | 96 |
131 DISALLOW_COPY_AND_ASSIGN(PulseAudioOutputStream); | 97 DISALLOW_COPY_AND_ASSIGN(PulseAudioOutputStream); |
132 }; | 98 }; |
133 | 99 |
134 } // namespace media | 100 } // namespace media |
135 | 101 |
136 #endif // MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ | 102 #endif // MEDIA_AUDIO_PULSE_PULSE_OUTPUT_H_ |
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