Contrast.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.media3.common.FrameProcessingException;
import androidx.media3.common.util.UnstableApi;
/** A {@link GlEffect} to control the contrast of video frames. */
@UnstableApi
public class Contrast implements GlEffect {
/** Adjusts the contrast of video frames in the interval [-1, 1]. */
public final float contrast;
/**
* Creates a new instance for the given contrast value.
*
* <p>Contrast values range from -1 (all gray pixels) to 1 (maximum difference of colors). 0 means
* to add no contrast and leaves the frames unchanged.
*/
public Contrast(float contrast) {
checkArgument(-1 <= contrast && contrast <= 1, "Contrast needs to be in the interval [-1, 1].");
this.contrast = contrast;
}
@Override
public SingleFrameGlTextureProcessor toGlTextureProcessor(Context context, boolean useHdr)
throws FrameProcessingException {
return new ContrastProcessor(context, this, useHdr);
}
}