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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_MAC_AUDIO_SYNCHRONIZED_MAC_H_ | |
6 #define MEDIA_AUDIO_MAC_AUDIO_SYNCHRONIZED_MAC_H_ | |
7 | |
8 #include <AudioToolbox/AudioToolbox.h> | |
9 #include <AudioUnit/AudioUnit.h> | |
10 #include <CoreAudio/CoreAudio.h> | |
11 | |
12 #include "base/compiler_specific.h" | |
13 #include "base/synchronization/lock.h" | |
14 #include "media/audio/audio_io.h" | |
15 #include "media/audio/audio_parameters.h" | |
16 #include "media/base/audio_bus.h" | |
17 #include "media/base/audio_fifo.h" | |
18 | |
19 namespace media { | |
20 | |
21 class AudioManagerMac; | |
22 | |
23 // AudioSynchronizedStream allows arbitrary combinations of input and output | |
24 // devices running off different clocks and using different drivers, with | |
25 // potentially differing sample-rates. It implements AudioOutputStream | |
26 // and shuttles its synchronized I/O data using AudioSourceCallback. | |
27 // | |
28 // It is required to first acquire the native sample rate of the selected | |
29 // output device and then use the same rate when creating this object. | |
30 // | |
31 // ............................................................................ | |
32 // Theory of Operation: | |
33 // . | |
34 // INPUT THREAD . OUTPUT THREAD | |
35 // +-----------------+ +------+ . | |
36 // | Input AudioUnit | --> | | . | |
37 // +-----------------+ | | . | |
38 // | FIFO | . | |
39 // | | +-----------+ | |
40 // | | -----> | Varispeed | | |
41 // | | +-----------+ | |
42 // +------+ . | | |
43 // . | +-----------+ | |
44 // . OnMoreIOData() --> | Output AU | | |
45 // . +-----------+ | |
46 // | |
47 // The input AudioUnit's InputProc is called on one thread which feeds the | |
48 // FIFO. The output AudioUnit's OutputProc is called on a second thread | |
49 // which pulls on the varispeed to get the current input data. The varispeed | |
50 // handles mismatches between input and output sample-rate and also clock drift | |
51 // between the input and output drivers. The varispeed consumes its data from | |
52 // the FIFO and adjusts its rate dynamically according to the amount | |
53 // of data buffered in the FIFO. If the FIFO starts getting too much data | |
54 // buffered then the varispeed will speed up slightly to compensate | |
55 // and similarly if the FIFO doesn't have enough data buffered then the | |
56 // varispeed will slow down slightly. | |
57 // | |
58 // Finally, once the input data is available then OnMoreIOData() is called | |
59 // which is given this input, and renders the output which is finally sent | |
60 // to the Output AudioUnit. | |
61 // | |
scherkus (not reviewing)
2012/09/17 14:51:17
remove extra // line
Chris Rogers
2012/09/17 20:44:23
Done.
| |
62 class AudioSynchronizedStream : public AudioOutputStream { | |
63 public: | |
64 // The ctor takes all the usual parameters, plus |manager| which is the | |
65 // the audio manager who is creating this object. | |
66 AudioSynchronizedStream(AudioManagerMac* manager, | |
67 const AudioParameters& params, | |
68 AudioDeviceID input_id, | |
69 AudioDeviceID output_id); | |
70 | |
71 virtual ~AudioSynchronizedStream(); | |
72 | |
73 // Implementation of AudioOutputStream. | |
74 virtual bool Open() OVERRIDE; | |
75 virtual void Close() OVERRIDE; | |
76 virtual void Start(AudioSourceCallback* callback) OVERRIDE; | |
77 virtual void Stop() OVERRIDE; | |
78 | |
79 virtual void SetVolume(double volume) OVERRIDE; | |
80 virtual void GetVolume(double* volume) OVERRIDE; | |
81 | |
82 OSStatus SetInputDeviceAsCurrent(AudioDeviceID input_id); | |
83 OSStatus SetOutputDeviceAsCurrent(AudioDeviceID output_id); | |
84 AudioDeviceID GetInputDeviceID() { return input_info_.id_; } | |
no longer working on chromium
2012/09/17 20:47:46
for the inline accessors use styles like get_input
Chris Rogers
2012/09/17 22:00:42
This is not a strict style rule, just a recommenda
| |
85 AudioDeviceID GetOutputDeviceID() { return output_info_.id_; } | |
no longer working on chromium
2012/09/17 20:47:46
ditto
| |
86 | |
87 bool IsRunning(); | |
88 | |
89 private: | |
90 // Initialization. | |
91 OSStatus CreateAudioUnits(); | |
92 OSStatus SetupInput(AudioDeviceID input_id); | |
93 OSStatus EnableIO(); | |
94 OSStatus SetupOutput(AudioDeviceID output_id); | |
95 OSStatus SetupCallbacks(); | |
96 OSStatus SetupStreamFormats(); | |
97 void AllocateInputData(); | |
98 | |
99 // Handlers for the AudioUnit callbacks. | |
100 OSStatus HandleInputCallback(AudioUnitRenderActionFlags* io_action_flags, | |
101 const AudioTimeStamp* time_stamp, | |
102 UInt32 bus_number, | |
103 UInt32 number_of_frames, | |
104 AudioBufferList* io_data); | |
105 | |
106 OSStatus HandleVarispeedCallback(AudioUnitRenderActionFlags* io_action_flags, | |
107 const AudioTimeStamp* time_stamp, | |
108 UInt32 bus_number, | |
109 UInt32 number_of_frames, | |
110 AudioBufferList* io_data); | |
111 | |
112 OSStatus HandleOutputCallback(AudioUnitRenderActionFlags* io_action_flags, | |
113 const AudioTimeStamp* time_stamp, | |
114 UInt32 bus_number, | |
115 UInt32 number_of_frames, | |
116 AudioBufferList* io_data); | |
117 | |
118 // AudioUnit callbacks. | |
119 static OSStatus InputProc(void* user_data, | |
120 AudioUnitRenderActionFlags* io_action_flags, | |
121 const AudioTimeStamp* time_stamp, | |
122 UInt32 bus_number, | |
123 UInt32 number_of_frames, | |
124 AudioBufferList* io_data); | |
125 | |
126 static OSStatus VarispeedProc(void* user_data, | |
127 AudioUnitRenderActionFlags* io_action_flags, | |
128 const AudioTimeStamp* time_stamp, | |
129 UInt32 bus_number, | |
130 UInt32 number_of_frames, | |
131 AudioBufferList* io_data); | |
132 | |
133 static OSStatus OutputProc(void* user_data, | |
134 AudioUnitRenderActionFlags* io_action_flags, | |
135 const AudioTimeStamp* time_stamp, | |
136 UInt32 bus_number, | |
137 UInt32 number_of_frames, | |
138 AudioBufferList* io_data); | |
139 | |
140 // Our creator. | |
141 AudioManagerMac* manager_; | |
142 | |
143 // Client parameters. | |
144 AudioParameters params_; | |
145 | |
146 double input_sample_rate_; | |
147 double output_sample_rate_; | |
148 | |
149 // Pointer to the object that will provide the audio samples. | |
150 AudioSourceCallback* source_; | |
151 | |
152 // Values used in Open(). | |
153 AudioDeviceID input_id_; | |
154 AudioDeviceID output_id_; | |
155 | |
156 // The input AudioUnit renders its data here. | |
157 AudioBufferList* input_buffer_list_; | |
158 | |
159 // Holds the actual data for |input_buffer_list_| | |
scherkus (not reviewing)
2012/09/17 14:51:17
add .
Chris Rogers
2012/09/17 20:44:23
Done.
| |
160 scoped_ptr<AudioBus> input_bus_; | |
161 | |
162 class AudioDeviceInfo { | |
163 public: | |
164 AudioDeviceInfo() | |
165 : id_(kAudioDeviceUnknown), | |
166 is_input_(false), | |
167 buffer_size_frames_(0) {} | |
168 void Initialize(AudioDeviceID inID, bool isInput); | |
169 bool IsInitialized() const { return id_ != kAudioDeviceUnknown; } | |
170 | |
171 AudioDeviceID id_; | |
172 bool is_input_; | |
173 UInt32 buffer_size_frames_; | |
174 }; | |
175 | |
176 AudioDeviceInfo input_info_; | |
177 AudioDeviceInfo output_info_; | |
178 | |
179 // Used for input to output buffering. | |
180 AudioFifo fifo_; | |
181 | |
182 double fifo_rate_compensation_; | |
183 double ave_delta_; | |
scherkus (not reviewing)
2012/09/17 14:51:17
what's ave_delta_?
if it's average can you use av
Chris Rogers
2012/09/17 20:44:23
Added comment and changed name as you suggested.
| |
184 | |
185 // The optimal number of frames we'd like to keep in the FIFO at all times. | |
186 int target_fifo_frames_; | |
187 | |
188 // AudioUnits. | |
189 AudioUnit input_unit_; | |
190 AudioUnit varispeed_unit_; | |
191 AudioUnit output_unit_; | |
192 | |
193 double first_input_time_; | |
194 | |
195 bool is_running_; | |
196 int hardware_buffer_size_; | |
197 int channels_; | |
198 | |
199 DISALLOW_COPY_AND_ASSIGN(AudioSynchronizedStream); | |
200 }; | |
201 | |
202 } // namespace media | |
203 | |
204 #endif // MEDIA_AUDIO_MAC_AUDIO_SYNCHRONIZED_MAC_H_ | |
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