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
|
/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.media;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import android.annotation.IntDef;
/**
* Structure that groups a position in frame units relative to an assumed audio stream,
* together with the estimated time when that frame enters or leaves the audio
* processing pipeline on that device. This can be used to coordinate events
* and interactions with the external environment.
* <p>
* The time is based on the implementation's best effort, using whatever knowledge
* is available to the system, but cannot account for any delay unknown to the implementation.
*
* @see AudioTrack#getTimestamp AudioTrack.getTimestamp(AudioTimestamp)
* @see AudioRecord#getTimestamp AudioRecord.getTimestamp(AudioTimestamp, int)
*/
public final class AudioTimestamp
{
/**
* Clock monotonic or its equivalent on the system,
* in the same units and timebase as {@link java.lang.System#nanoTime}.
*/
public static final int TIMEBASE_MONOTONIC = 0;
/**
* Clock monotonic including suspend time or its equivalent on the system,
* in the same units and timebase as {@link android.os.SystemClock#elapsedRealtimeNanos}.
*/
public static final int TIMEBASE_BOOTTIME = 1;
/** @hide */
@IntDef({
TIMEBASE_MONOTONIC,
TIMEBASE_BOOTTIME,
})
@Retention(RetentionPolicy.SOURCE)
public @interface Timebase {}
/**
* Position in frames relative to start of an assumed audio stream.
* <p>
* When obtained through
* {@link AudioRecord#getTimestamp AudioRecord.getTimestamp(AudioTimestamp, int)},
* all 64 bits of position are valid.
* <p>
* When obtained through
* {@link AudioTrack#getTimestamp AudioTrack.getTimestamp(AudioTimestamp)},
* the low-order 32 bits of position is in wrapping frame units similar to
* {@link AudioTrack#getPlaybackHeadPosition AudioTrack.getPlaybackHeadPosition()}.
*/
public long framePosition;
/**
* Time associated with the frame in the audio pipeline.
* <p>
* When obtained through
* {@link AudioRecord#getTimestamp AudioRecord.getTimestamp(AudioTimestamp, int)},
* this is the estimated time in nanoseconds when the frame referred to by
* {@link #framePosition} was captured. The timebase is either
* {@link #TIMEBASE_MONOTONIC} or {@link #TIMEBASE_BOOTTIME}, depending
* on the timebase parameter used in
* {@link AudioRecord#getTimestamp AudioRecord.getTimestamp(AudioTimestamp, int)}.
* <p>
* When obtained through
* {@link AudioTrack#getTimestamp AudioTrack.getTimestamp(AudioTimestamp)},
* this is the estimated time when the frame was presented or is committed to be presented,
* with a timebase of {@link #TIMEBASE_MONOTONIC}.
*/
public long nanoTime;
}
|
