Shader portion is bloat given we're scaling and biasing the colors. Swap out implementation.

PiperOrigin-RevId: 524113489

libraries/effect/src/androidTest/java/androidx/media3/effect/ContrastPixelTest.java

@@ -45,7 +45,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 /**
- * Pixel test for contrast adjustment via {@link ContrastShaderProgram}.
+ * Pixel test for contrast adjustment via {@link Contrast}.
  *
  * <p>Expected images are taken from an emulator, so tests on different emulators or physical
  * devices may fail. To test on other devices, please increase the {@link

libraries/effect/src/main/assets/shaders/fragment_shader_contrast_es2.glsl

@@ -1,33 +0,0 @@
-#version 100
-// 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.
-
-// ES 2 fragment shader that samples from a (non-external) texture with
-// uTexSampler, copying from this texture to the current output
-// while adjusting contrast based on uContrastFactor.
-
-precision mediump float;
-uniform sampler2D uTexSampler;
-uniform float uContrastFactor;
-varying vec2 vTexSamplingCoord;
-
-void main() {
-    vec4 inputColor = texture2D(uTexSampler, vTexSamplingCoord);
-
-    gl_FragColor = vec4(
-        uContrastFactor * (inputColor.r - 0.5) + 0.5,
-        uContrastFactor * (inputColor.g - 0.5) + 0.5,
-        uContrastFactor * (inputColor.b - 0.5) + 0.5,
-        inputColor.a);
-}

libraries/effect/src/main/java/androidx/media3/effect/Contrast.java

@@ -18,17 +18,17 @@ package androidx.media3.effect;
 
 import static androidx.media3.common.util.Assertions.checkArgument;
 
-import android.content.Context;
 import androidx.annotation.FloatRange;
-import androidx.media3.common.VideoFrameProcessingException;
 import androidx.media3.common.util.UnstableApi;
 
-/** A {@link GlEffect} to control the contrast of video frames. */
+/** A {@link RgbMatrix} to control the contrast of video frames. */
 @UnstableApi
-public class Contrast implements GlEffect {
+public class Contrast implements RgbMatrix {
 
   /** Adjusts the contrast of video frames in the interval [-1, 1]. */
-  public final float contrast;
+  private final float contrast;
+
+  private final float[] contrastMatrix;
 
   /**
    * Creates a new instance for the given contrast value.
@@ -39,12 +39,33 @@ public class Contrast implements GlEffect {
   public Contrast(@FloatRange(from = -1, to = 1) float contrast) {
     checkArgument(-1 <= contrast && contrast <= 1, "Contrast needs to be in the interval [-1, 1].");
     this.contrast = contrast;
+    float contrastFactor = (1 + contrast) / (1.0001f - contrast);
+    contrastMatrix =
+        new float[] {
+          contrastFactor,
+          0.0f,
+          0.0f,
+          0.0f,
+          0.0f,
+          contrastFactor,
+          0.0f,
+          0.0f,
+          0.0f,
+          0.0f,
+          contrastFactor,
+          0.0f,
+          (1.0f - contrastFactor) * 0.5f,
+          (1.0f - contrastFactor) * 0.5f,
+          (1.0f - contrastFactor) * 0.5f,
+          1.0f
+        };
   }
 
   @Override
-  public SingleFrameGlShaderProgram toGlShaderProgram(Context context, boolean useHdr)
+  public float[] getMatrix(long presentationTimeUs, boolean useHdr) {
-      throws VideoFrameProcessingException {
+    // Implementation is not currently time-varying, therefore matrix should not be changing between
-    return new ContrastShaderProgram(context, this, useHdr);
+    // frames.
+    return contrastMatrix;
   }
 
   @Override

libraries/effect/src/main/java/androidx/media3/effect/ContrastShaderProgram.java

@@ -1,96 +0,0 @@
-/*
- * 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 android.content.Context;
-import android.opengl.GLES20;
-import androidx.media3.common.VideoFrameProcessingException;
-import androidx.media3.common.util.GlProgram;
-import androidx.media3.common.util.GlUtil;
-import androidx.media3.common.util.Size;
-import java.io.IOException;
-
-/** Applies a {@link Contrast} to each frame in the fragment shader. */
-/* package */ final class ContrastShaderProgram extends SingleFrameGlShaderProgram {
-  private static final String VERTEX_SHADER_PATH = "shaders/vertex_shader_transformation_es2.glsl";
-  private static final String FRAGMENT_SHADER_PATH = "shaders/fragment_shader_contrast_es2.glsl";
-
-  private final GlProgram glProgram;
-
-  /**
-   * Creates a new instance.
-   *
-   * @param context The {@link Context}.
-   * @param contrastEffect The {@link Contrast} to apply to each frame in order.
-   * @param useHdr Whether input textures come from an HDR source. If {@code true}, colors will be
-   *     in linear RGB BT.2020. If {@code false}, colors will be in linear RGB BT.709.
-   * @throws VideoFrameProcessingException If a problem occurs while reading shader files.
-   */
-  public ContrastShaderProgram(Context context, Contrast contrastEffect, boolean useHdr)
-      throws VideoFrameProcessingException {
-    super(useHdr);
-    // Use 1.0001f to avoid division by zero issues.
-    float contrastFactor = (1 + contrastEffect.contrast) / (1.0001f - contrastEffect.contrast);
-
-    try {
-      glProgram = new GlProgram(context, VERTEX_SHADER_PATH, FRAGMENT_SHADER_PATH);
-    } catch (IOException | GlUtil.GlException e) {
-      throw new VideoFrameProcessingException(e);
-    }
-
-    // Draw the frame on the entire normalized device coordinate space, from -1 to 1, for x and y.
-    glProgram.setBufferAttribute(
-        "aFramePosition",
-        GlUtil.getNormalizedCoordinateBounds(),
-        GlUtil.HOMOGENEOUS_COORDINATE_VECTOR_SIZE);
-
-    float[] identityMatrix = GlUtil.create4x4IdentityMatrix();
-    glProgram.setFloatsUniform("uTransformationMatrix", identityMatrix);
-    glProgram.setFloatsUniform("uTexTransformationMatrix", identityMatrix);
-    glProgram.setFloatUniform("uContrastFactor", contrastFactor);
-  }
-
-  @Override
-  public Size configure(int inputWidth, int inputHeight) {
-    return new Size(inputWidth, inputHeight);
-  }
-
-  @Override
-  public void drawFrame(int inputTexId, long presentationTimeUs)
-      throws VideoFrameProcessingException {
-    try {
-      glProgram.use();
-      glProgram.setSamplerTexIdUniform("uTexSampler", inputTexId, /* texUnitIndex= */ 0);
-      glProgram.bindAttributesAndUniforms();
-
-      // The four-vertex triangle strip forms a quad.
-      GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, /* first= */ 0, /* count= */ 4);
-    } catch (GlUtil.GlException e) {
-      throw new VideoFrameProcessingException(e, presentationTimeUs);
-    }
-  }
-
-  @Override
-  public void release() throws VideoFrameProcessingException {
-    super.release();
-    try {
-      glProgram.delete();
-    } catch (GlUtil.GlException e) {
-      throw new VideoFrameProcessingException(e);
-    }
-  }
-}