RgbAdjustment.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.opengl.Matrix;
import androidx.annotation.FloatRange;
import androidx.media3.common.util.GlUtil;
import androidx.media3.common.util.UnstableApi;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Arrays;
/** Scales the red, green, and blue color channels of a frame. */
@UnstableApi
public final class RgbAdjustment implements RgbMatrix {
/** A builder for {@link RgbAdjustment} instances. */
public static final class Builder {
private float redScale;
private float greenScale;
private float blueScale;
/** Creates a new instance with default values. */
public Builder() {
redScale = 1;
greenScale = 1;
blueScale = 1;
}
/**
* Scales the red channel of the frame by {@code redScale}.
*
* @param redScale The scale to apply to the red channel. Needs to be non-negative and the
* default value is {@code 1}.
*/
@CanIgnoreReturnValue
public Builder setRedScale(@FloatRange(from = 0) float redScale) {
checkArgument(0 <= redScale, "Red scale needs to be non-negative.");
this.redScale = redScale;
return this;
}
/**
* Scales the green channel of the frame by {@code greenScale}.
*
* @param greenScale The scale to apply to the green channel. Needs to be non-negative and the
* default value is {@code 1}.
*/
@CanIgnoreReturnValue
public Builder setGreenScale(@FloatRange(from = 0) float greenScale) {
checkArgument(0 <= greenScale, "Green scale needs to be non-negative.");
this.greenScale = greenScale;
return this;
}
/**
* Scales the blue channel of the frame by {@code blueScale}.
*
* @param blueScale The scale to apply to the blue channel. Needs to be non-negative and the
* default value is {@code 1}.
*/
@CanIgnoreReturnValue
public Builder setBlueScale(@FloatRange(from = 0) float blueScale) {
checkArgument(0 <= blueScale, "Blue scale needs to be non-negative.");
this.blueScale = blueScale;
return this;
}
/** Creates a new {@link RgbAdjustment} instance. */
public RgbAdjustment build() {
float[] rgbMatrix = GlUtil.create4x4IdentityMatrix();
Matrix.scaleM(
rgbMatrix, /* smOffset= */ 0, /* x= */ redScale, /* y= */ greenScale, /* z= */ blueScale);
return new RgbAdjustment(rgbMatrix);
}
}
private final float[] rgbMatrix;
private RgbAdjustment(float[] rgbMatrix) {
this.rgbMatrix = rgbMatrix;
}
@Override
public float[] getMatrix(long presentationTimeUs, boolean useHdr) {
return rgbMatrix;
}
@Override
public boolean isNoOp(int inputWidth, int inputHeight) {
return Arrays.equals(rgbMatrix, GlUtil.create4x4IdentityMatrix());
}
}