1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/* Copyright 2014 The Chromium Authors
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* From ppb_media_stream_audio_track.idl modified Wed May 28 09:36:15 2014. */
#ifndef PPAPI_C_PPB_MEDIA_STREAM_AUDIO_TRACK_H_
#define PPAPI_C_PPB_MEDIA_STREAM_AUDIO_TRACK_H_
#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_completion_callback.h"
#include "ppapi/c/pp_macros.h"
#include "ppapi/c/pp_resource.h"
#include "ppapi/c/pp_stdint.h"
#include "ppapi/c/pp_var.h"
#define PPB_MEDIASTREAMAUDIOTRACK_INTERFACE_0_1 "PPB_MediaStreamAudioTrack;0.1"
#define PPB_MEDIASTREAMAUDIOTRACK_INTERFACE \
PPB_MEDIASTREAMAUDIOTRACK_INTERFACE_0_1
/**
* @file
* Defines the <code>PPB_MediaStreamAudioTrack</code> interface. Used for
* receiving audio samples from a MediaStream audio track in the browser.
*/
/**
* @addtogroup Enums
* @{
*/
/**
* This enumeration contains audio track attributes which are used by
* <code>Configure()</code>.
*/
typedef enum {
/**
* Attribute list terminator.
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_NONE = 0,
/**
* The maximum number of buffers to hold audio samples.
* Note: this is only used as advisory; the browser may allocate more or fewer
* based on available resources. How many buffers depends on usage -
* request at least 2 to make sure latency doesn't cause lost samples. If
* the plugin expects to hold on to more than one buffer at a time (e.g. to do
* multi-buffer processing), it should request that many more.
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_BUFFERS = 1,
/**
* The sample rate of audio data in buffers. The attribute value is a
* <code>PP_AudioBuffer_SampleRate</code>.
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_SAMPLE_RATE = 2,
/**
* The sample size of audio data in buffers in bytes. The attribute value is a
* <code>PP_AudioBuffer_SampleSize</code>.
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_SAMPLE_SIZE = 3,
/**
* The number of channels in audio buffers.
*
* Supported values: 1, 2
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_CHANNELS = 4,
/**
* The duration of an audio buffer in milliseconds.
*
* Valid range: 10 to 10000
*/
PP_MEDIASTREAMAUDIOTRACK_ATTRIB_DURATION = 5
} PP_MediaStreamAudioTrack_Attrib;
/**
* @}
*/
/**
* @addtogroup Interfaces
* @{
*/
struct PPB_MediaStreamAudioTrack_0_1 {
/**
* Determines if a resource is a MediaStream audio track resource.
*
* @param[in] resource The <code>PP_Resource</code> to test.
*
* @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
* resource is a Mediastream audio track resource or <code>PP_FALSE</code>
* otherwise.
*/
PP_Bool (*IsMediaStreamAudioTrack)(PP_Resource resource);
/**
* Configures underlying buffers for incoming audio samples.
* If the application doesn't want to drop samples, then the
* <code>PP_MEDIASTREAMAUDIOTRACK_ATTRIB_BUFFERS</code> should be
* chosen such that inter-buffer processing time variability won't overrun all
* the input buffers. If all buffers are filled, then samples will be
* dropped. The application can detect this by examining the timestamp on
* returned buffers. If <code>Configure()</code> is not called, default
* settings will be used. Calls to Configure while the plugin holds
* buffers will fail.
* Example usage from plugin code:
* @code
* int32_t attribs[] = {
* PP_MEDIASTREAMAUDIOTRACK_ATTRIB_BUFFERS, 4,
* PP_MEDIASTREAMAUDIOTRACK_ATTRIB_DURATION, 10,
* PP_MEDIASTREAMAUDIOTRACK_ATTRIB_NONE};
* track_if->Configure(track, attribs, callback);
* @endcode
*
* @param[in] audio_track A <code>PP_Resource</code> corresponding to an audio
* resource.
* @param[in] attrib_list A list of attribute name-value pairs in which each
* attribute is immediately followed by the corresponding desired value.
* The list is terminated by
* <code>PP_MEDIASTREAMAUDIOTRACK_ATTRIB_NONE</code>.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion of <code>Configure()</code>.
*
* @return An int32_t containing a result code from <code>pp_errors.h</code>.
*/
int32_t (*Configure)(PP_Resource audio_track,
const int32_t attrib_list[],
struct PP_CompletionCallback callback);
/**
* Gets attribute value for a given attribute name.
*
* @param[in] audio_track A <code>PP_Resource</code> corresponding to an audio
* resource.
* @param[in] attrib A <code>PP_MediaStreamAudioTrack_Attrib</code> for
* querying.
* @param[out] value A int32_t for storing the attribute value on success.
* Otherwise, the value will not be changed.
*
* @return An int32_t containing a result code from <code>pp_errors.h</code>.
*/
int32_t (*GetAttrib)(PP_Resource audio_track,
PP_MediaStreamAudioTrack_Attrib attrib,
int32_t* value);
/**
* Returns the track ID of the underlying MediaStream audio track.
*
* @param[in] audio_track The <code>PP_Resource</code> to check.
*
* @return A <code>PP_Var</code> containing the MediaStream track ID as
* a string.
*/
struct PP_Var (*GetId)(PP_Resource audio_track);
/**
* Checks whether the underlying MediaStream track has ended.
* Calls to GetBuffer while the track has ended are safe to make and will
* complete, but will fail.
*
* @param[in] audio_track The <code>PP_Resource</code> to check.
*
* @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given
* MediaStream track has ended or <code>PP_FALSE</code> otherwise.
*/
PP_Bool (*HasEnded)(PP_Resource audio_track);
/**
* Gets the next audio buffer from the MediaStream track.
* If internal processing is slower than the incoming buffer rate, new buffers
* will be dropped from the incoming stream. Once all buffers are full,
* audio samples will be dropped until <code>RecycleBuffer()</code> is called
* to free a slot for another buffer.
* If there are no audio data in the input buffer,
* <code>PP_OK_COMPLETIONPENDING</code> will be returned immediately and the
* <code>callback</code> will be called, when a new buffer of audio samples
* is received or an error happens.
*
* @param[in] audio_track A <code>PP_Resource</code> corresponding to an audio
* resource.
* @param[out] buffer A <code>PP_Resource</code> corresponding to
* an AudioBuffer resource.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion of GetBuffer().
*
* @return An int32_t containing a result code from <code>pp_errors.h</code>.
*/
int32_t (*GetBuffer)(PP_Resource audio_track,
PP_Resource* buffer,
struct PP_CompletionCallback callback);
/**
* Recycles a buffer returned by <code>GetBuffer()</code>, so the track can
* reuse the buffer. And the buffer will become invalid. The caller should
* release all references it holds to <code>buffer</code> and not use it
* anymore.
*
* @param[in] audio_track A <code>PP_Resource</code> corresponding to an audio
* resource.
* @param[in] buffer A <code>PP_Resource</code> corresponding to
* an AudioBuffer resource returned by <code>GetBuffer()</code>.
*
* @return An int32_t containing a result code from <code>pp_errors.h</code>.
*/
int32_t (*RecycleBuffer)(PP_Resource audio_track, PP_Resource buffer);
/**
* Closes the MediaStream audio track and disconnects it from the audio
* source. After calling <code>Close()</code>, no new buffers will be
* received.
*
* @param[in] audio_track A <code>PP_Resource</code> corresponding to a
* MediaStream audio track resource.
*/
void (*Close)(PP_Resource audio_track);
};
typedef struct PPB_MediaStreamAudioTrack_0_1 PPB_MediaStreamAudioTrack;
/**
* @}
*/
#endif /* PPAPI_C_PPB_MEDIA_STREAM_AUDIO_TRACK_H_ */
|
