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/*
* Copyright 2015 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 android.annotation.FloatRange;
/**
* An immutable object that represents the linear correlation between the media time
* and the system time. It contains the media clock rate, together with the media timestamp
* of an anchor frame and the system time when that frame was presented or is committed
* to be presented.
*
* The phrase "present" means that audio/video produced on device is detectable by an external
* observer off device.
* 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.
* The anchor frame could be any frame, including a just-rendered frame, or even a theoretical
* or in-between frame, based on the source of the MediaTimestamp.
* When the anchor frame is a just-rendered one, the media time stands for
* current position of the playback or recording.
*
* @see MediaSync#getTimestamp
* @see MediaPlayer#getTimestamp
*/
public final class MediaTimestamp
{
/**
* An unknown media timestamp value
*/
public static final MediaTimestamp TIMESTAMP_UNKNOWN = new MediaTimestamp(-1, -1, 0.0f);
/**
* Get the media time of the anchor in microseconds.
*/
public long getAnchorMediaTimeUs() {
return mediaTimeUs;
}
/**
* Get the {@link java.lang.System#nanoTime system time} corresponding to the media time
* in nanoseconds.
* @deprecated use {@link #getAnchorSystemNanoTime} instead.
*/
@Deprecated
public long getAnchorSytemNanoTime() {
return getAnchorSystemNanoTime();
}
/**
* Get the {@link java.lang.System#nanoTime system time} corresponding to the media time
* in nanoseconds.
*/
public long getAnchorSystemNanoTime() {
return nanoTime;
}
/**
* Get the rate of the media clock in relation to the system time.
*
* It is 1.0 if media clock advances in sync with the system clock;
* greater than 1.0 if media clock is faster than the system clock;
* less than 1.0 if media clock is slower than the system clock.
*/
@FloatRange(from = 0.0f, to = Float.MAX_VALUE)
public float getMediaClockRate() {
return clockRate;
}
/** @hide - accessor shorthand */
public final long mediaTimeUs;
/** @hide - accessor shorthand */
public final long nanoTime;
/** @hide - accessor shorthand */
public final float clockRate;
/**
* Constructor.
*
* @param mediaTimeUs the media time of the anchor in microseconds
* @param nanoTimeNs the {@link java.lang.System#nanoTime system time} corresponding to the
* media time in nanoseconds.
* @param clockRate the rate of the media clock in relation to the system time.
*/
public MediaTimestamp(long mediaTimeUs, long nanoTimeNs,
@FloatRange(from = 0.0f, to = Float.MAX_VALUE) float clockRate) {
this.mediaTimeUs = mediaTimeUs;
this.nanoTime = nanoTimeNs;
this.clockRate = clockRate;
}
/** @hide */
MediaTimestamp() {
mediaTimeUs = 0;
nanoTime = 0;
clockRate = 1.0f;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null || getClass() != obj.getClass()) return false;
final MediaTimestamp that = (MediaTimestamp) obj;
return (this.mediaTimeUs == that.mediaTimeUs)
&& (this.nanoTime == that.nanoTime)
&& (this.clockRate == that.clockRate);
}
@Override
public String toString() {
return getClass().getName()
+ "{AnchorMediaTimeUs=" + mediaTimeUs
+ " AnchorSystemNanoTime=" + nanoTime
+ " clockRate=" + clockRate
+ "}";
}
}