FrameCache.java
/*
* Copyright 2022 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 androidx.media3.effect;
import static androidx.media3.common.util.Assertions.checkArgument;
import android.content.Context;
import androidx.annotation.IntRange;
import androidx.media3.common.VideoFrameProcessingException;
import androidx.media3.common.util.UnstableApi;
/**
* Caches the input frames.
*
* <p>Example usage: cache the processed frames when presenting them on screen, to accommodate for
* the possible fluctuation in video frame processing time between frames.
*/
@UnstableApi
public final class FrameCache implements GlEffect {
/** The capacity of the frame cache. */
public final int capacity;
/**
* Creates a new instance.
*
* <p>The {@code capacity} should be chosen carefully. OpenGL could crash unexpectedly if the
* device is not capable of allocating the requested buffer.
*
* <p>Currently up to 8 frames can be cached in one {@code FrameCache} instance.
*
* @param capacity The capacity of the frame cache, must be greater than zero.
*/
public FrameCache(@IntRange(from = 1, to = 8) int capacity) {
// TODO(b/243033952) Consider adding a global limit across many FrameCache instances.
checkArgument(capacity > 0 && capacity < 9);
this.capacity = capacity;
}
@Override
public GlShaderProgram toGlShaderProgram(Context context, boolean useHdr)
throws VideoFrameProcessingException {
return new FrameCacheGlShaderProgram(context, capacity, useHdr);
}
}