Add HSL Adjustments to the effects module.

PiperOrigin-RevId: 476144167
(cherry picked from commit 2c27cd82)

google3/third_party/java_src/android_libs/media/libraries/effect/src/main/assets/shaders/fragment_shader_hsl_es2.glsl

+#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. It then converts the RGB color input into HSL and adjusts
+// the Hue, Saturation, and Lightness and converts it then back to RGB.
+
+// We use the algorithm based on the work by Sam Hocevar, which optimizes
+// for an efficient branchless RGB <-> HSL conversion. A blog post is
+// at https://www.chilliant.com/rgb2hsv.html and it is further explained at
+// http://lolengine.net/blog/2013/01/13/fast-rgb-to-hsv.
+
+precision highp float;
+uniform sampler2D uTexSampler;
+// uHueAdjustmentDegrees, uSaturationAdjustment, and uLightnessAdjustment
+// are normalized to the unit interval [0, 1].
+uniform float uHueAdjustmentDegrees;
+uniform float uSaturationAdjustment;
+uniform float uLightnessAdjustment;
+varying vec2 vTexSamplingCoord;
+
+const float epsilon = 1e-10;
+
+vec3 rgbToHcv(vec3 rgb) {
+    vec4 p = (rgb.g < rgb.b)
+        ? vec4(rgb.bg, -1.0, 2.0 / 3.0)
+        : vec4(rgb.gb, 0.0, -1.0 / 3.0);
+    vec4 q = (rgb.r < p.x)
+        ? vec4(p.xyw, rgb.r)
+        : vec4(rgb.r, p.yzx);
+    float c = q.x - min(q.w, q.y);
+    float h = abs((q.w - q.y) / (6.0 * c + epsilon) + q.z);
+    return vec3(h, c, q.x);
+}
+
+vec3 rgbToHsl(vec3 rgb) {
+    vec3 hcv = rgbToHcv(rgb);
+    float l = hcv.z - hcv.y * 0.5;
+    float s = hcv.y / (1.0 - abs(l * 2.0 - 1.0) + epsilon);
+    return vec3(hcv.x, s, l);
+}
+
+vec3 hueToRgb(float hue) {
+    float r = abs(hue * 6.0 - 3.0) - 1.0;
+    float g = 2.0 - abs(hue * 6.0 - 2.0);
+    float b = 2.0 - abs(hue * 6.0 - 4.0);
+    return clamp(vec3(r, g, b), 0.0, 1.0);
+}
+
+vec3 hslToRgb(vec3 hsl) {
+    vec3 rgb = hueToRgb(hsl.x);
+    float c = (1.0 - abs(2.0 * hsl.z - 1.0)) * hsl.y;
+    return (rgb - 0.5) * c + hsl.z;
+}
+
+void main() {
+    vec4 inputColor = texture2D(uTexSampler, vTexSamplingCoord);
+    vec3 hslColor = rgbToHsl(inputColor.rgb);
+
+    hslColor.x = mod(hslColor.x + uHueAdjustmentDegrees, 1.0);
+    hslColor.y = clamp(hslColor.y + uSaturationAdjustment, 0.0, 1.0);
+    hslColor.z = clamp(hslColor.z + uLightnessAdjustment, 0.0, 1.0);
+
+    gl_FragColor = vec4(hslToRgb(hslColor), inputColor.a);
+}

google3/third_party/java_src/android_libs/media/libraries/effect/src/main/java/androidx/media3/effect/HslAdjustment.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 com.google.android.exoplayer2.util.Assertions.checkArgument;
+
+import android.content.Context;
+import androidx.media3.common.FrameProcessingException;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+
+/** Adjusts the HSL (Hue, Saturation, and Lightness) of a frame. */
+public class HslAdjustment implements GlEffect {
+
+  /** A builder for {@code HslAdjustment} instances. */
+  public static final class Builder {
+    private float hueAdjustment;
+    private float saturationAdjustment;
+    private float lightnessAdjustment;
+
+    /** Creates a new instance with the default values. */
+    public Builder() {}
+
+    /**
+     * Rotates the hue of the frame by {@code hueAdjustmentDegrees}.
+     *
+     * <p>The Hue of the frame is defined in the interval of [0, 360] degrees. The actual degrees of
+     * hue adjustment applied is {@code hueAdjustmentDegrees % 360}.
+     *
+     * @param hueAdjustmentDegrees The hue adjustment in rotation degrees. The default value is
+     *     {@code 0}, which means no change is applied.
+     */
+    @CanIgnoreReturnValue
+    public Builder adjustHue(float hueAdjustmentDegrees) {
+      hueAdjustment = hueAdjustmentDegrees % 360;
+      return this;
+    }
+
+    /**
+     * Adjusts the saturation of the frame by {@code saturationAdjustment}.
+     *
+     * <p>Saturation is defined in the interval of [0, 100] where a saturation of {@code 0} will
+     * generate a grayscale frame and a saturation of {@code 100} has a maximum separation between
+     * the colors.
+     *
+     * @param saturationAdjustment The difference of how much the saturation will be adjusted in
+     *     either direction. Needs to be in the interval of [-100, 100] and the default value is
+     *     {@code 0}, which means no change is applied.
+     */
+    @CanIgnoreReturnValue
+    public Builder adjustSaturation(float saturationAdjustment) {
+      checkArgument(
+          -100 <= saturationAdjustment && saturationAdjustment <= 100,
+          "Can adjust the saturation by only 100 in either direction, but provided "
+              + saturationAdjustment);
+      this.saturationAdjustment = saturationAdjustment;
+      return this;
+    }
+
+    /**
+     * Adjusts the lightness of the frame by {@code lightnessAdjustment}.
+     *
+     * <p>Lightness is defined in the interval of [0, 100] where a lightness of {@code 0} is a black
+     * frame and a lightness of {@code 100} is a white frame.
+     *
+     * @param lightnessAdjustment The difference by how much the lightness will be adjusted in
+     *     either direction. Needs to be in the interval of [-100, 100] and the default value is
+     *     {@code 0}, which means no change is applied.
+     */
+    @CanIgnoreReturnValue
+    public Builder adjustLightness(float lightnessAdjustment) {
+      checkArgument(
+          -100 <= lightnessAdjustment && lightnessAdjustment <= 100,
+          "Can adjust the lightness by only 100 in either direction, but provided "
+              + lightnessAdjustment);
+      this.lightnessAdjustment = lightnessAdjustment;
+      return this;
+    }
+
+    /** Creates a new {@link HslAdjustment} instance. */
+    public HslAdjustment build() {
+      return new HslAdjustment(hueAdjustment, saturationAdjustment, lightnessAdjustment);
+    }
+  }
+
+  /** Indicates the hue adjustment in degrees. */
+  public final float hueAdjustmentDegrees;
+  /** Indicates the saturation adjustment. */
+  public final float saturationAdjustment;
+  /** Indicates the lightness adjustment. */
+  public final float lightnessAdjustment;
+
+  private HslAdjustment(
+      float hueAdjustmentDegrees, float saturationAdjustment, float lightnessAdjustment) {
+    this.hueAdjustmentDegrees = hueAdjustmentDegrees;
+    this.saturationAdjustment = saturationAdjustment;
+    this.lightnessAdjustment = lightnessAdjustment;
+  }
+
+  @Override
+  public HslProcessor toGlTextureProcessor(Context context, boolean useHdr)
+      throws FrameProcessingException {
+    return new HslProcessor(context, /* hslAdjustment= */ this, useHdr);
+  }
+}

google3/third_party/java_src/android_libs/media/libraries/effect/src/main/java/androidx/media3/effect/HslProcessor.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 com.google.android.exoplayer2.util.Assertions.checkArgument;
+
+import android.content.Context;
+import android.opengl.GLES20;
+import android.opengl.Matrix;
+import android.util.Pair;
+import androidx.media3.common.FrameProcessingException;
+import com.google.android.exoplayer2.util.GlProgram;
+import com.google.android.exoplayer2.util.GlUtil;
+import java.io.IOException;
+
+/** Applies the {@link HslAdjustment} to each frame in the fragment shader. */
+/* package */ final class HslProcessor extends SingleFrameGlTextureProcessor {
+  private static final String VERTEX_SHADER_PATH = "shaders/vertex_shader_transformation_es2.glsl";
+  private static final String FRAGMENT_SHADER_PATH = "shaders/fragment_shader_hsl_es2.glsl";
+
+  private final GlProgram glProgram;
+
+  /**
+   * Creates a new instance.
+   *
+   * @param context The {@link Context}.
+   * @param hslAdjustment The {@link HslAdjustment} 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 gamma RGB BT.709.
+   * @throws FrameProcessingException If a problem occurs while reading shader files.
+   */
+  public HslProcessor(Context context, HslAdjustment hslAdjustment, boolean useHdr)
+      throws FrameProcessingException {
+    super(useHdr);
+    // TODO(b/241241680): Check if HDR <-> HSL works the same or not.
+    checkArgument(!useHdr, "HDR is not yet supported.");
+
+    try {
+      glProgram = new GlProgram(context, VERTEX_SHADER_PATH, FRAGMENT_SHADER_PATH);
+    } catch (IOException | GlUtil.GlException e) {
+      throw new FrameProcessingException(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 = new float[16];
+    Matrix.setIdentityM(identityMatrix, /* smOffset= */ 0);
+    glProgram.setFloatsUniform("uTransformationMatrix", identityMatrix);
+    glProgram.setFloatsUniform("uTexTransformationMatrix", identityMatrix);
+
+    // OpenGL operates in a [0, 1] unit range and thus we transform the HSL intervals into
+    // the unit interval as well. The hue is defined in the [0, 360] interval and saturation
+    // and lightness in the [0, 100] interval.
+    glProgram.setFloatUniform("uHueAdjustmentDegrees", hslAdjustment.hueAdjustmentDegrees / 360);
+    glProgram.setFloatUniform("uSaturationAdjustment", hslAdjustment.saturationAdjustment / 100);
+    glProgram.setFloatUniform("uLightnessAdjustment", hslAdjustment.lightnessAdjustment / 100);
+  }
+
+  @Override
+  public Pair<Integer, Integer> configure(int inputWidth, int inputHeight) {
+    return Pair.create(inputWidth, inputHeight);
+  }
+
+  @Override
+  public void drawFrame(int inputTexId, long presentationTimeUs) throws FrameProcessingException {
+    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 FrameProcessingException(e, presentationTimeUs);
+    }
+  }
+}