HDR: Update limited range and add full range YUV to RGB color transforms.

PiperOrigin-RevId: 467910378

demos/transformer/src/main/java/androidx/media3/demo/transformer/ConfigurationActivity.java

@@ -96,7 +96,7 @@ public final class ConfigurationActivity extends AppCompatActivity {
     "H264 video and AAC audio (portrait, H < W, 90\u00B0)",
     "H264 video and AAC audio (portrait, H < W, 90\u00B0)",
     "SEF slow motion with 240 fps",
     "SEF slow motion with 240 fps",
     "480p DASH (non-square pixels)",
     "480p DASH (non-square pixels)",
-    "HDR (HDR10) H265 video (encoding may fail)",
+    "HDR (HDR10) H265 limited range video (encoding may fail)",
   };
   };
   private static final String[] DEMO_EFFECTS = {
   private static final String[] DEMO_EFFECTS = {
     "Dizzy crop",
     "Dizzy crop",

libraries/effect/src/main/assets/shaders/fragment_shader_copy_external_yuv_es3.glsl

@@ -18,7 +18,7 @@
 //    the sampler uses the EXT_YUV_target extension specified at
 //    the sampler uses the EXT_YUV_target extension specified at
 //    https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_YUV_target.txt,
 //    https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_YUV_target.txt,
 // 2. Applies a YUV to RGB conversion using the specified color transform
 // 2. Applies a YUV to RGB conversion using the specified color transform
-//    uColorTransform, yielding HLG BT.2020 RGB,
+//    uYuvToRgbColorTransform, yielding HLG BT.2020 RGB,
 // 3. If uApplyHlgOetf is 1, outputs HLG BT.2020 RGB. If 0, outputs
 // 3. If uApplyHlgOetf is 1, outputs HLG BT.2020 RGB. If 0, outputs
 //    linear BT.2020 RGB for intermediate shaders by applying the HLG OETF.
 //    linear BT.2020 RGB for intermediate shaders by applying the HLG OETF.
 // 4. Copies this converted texture color to the current output.
 // 4. Copies this converted texture color to the current output.
@@ -27,8 +27,7 @@
 #extension GL_EXT_YUV_target : require
 #extension GL_EXT_YUV_target : require
 precision mediump float;
 precision mediump float;
 uniform __samplerExternal2DY2YEXT uTexSampler;
 uniform __samplerExternal2DY2YEXT uTexSampler;
-// YUV to RGB conversion matrix.
-uniform mat3 uColorTransform;
+uniform mat3 uYuvToRgbColorTransform;
 uniform float uApplyHlgOetf;
 uniform float uApplyHlgOetf;
 in vec2 vTexSamplingCoord;
 in vec2 vTexSamplingCoord;
 out vec4 outColor;
 out vec4 outColor;
@@ -63,8 +62,9 @@ highp vec4 hlgOetf(highp vec4 hlgColor) {
 
 
 /** Convert YUV to RGBA. */
 /** Convert YUV to RGBA. */
 vec4 yuvToRgba(vec3 yuv) {
 vec4 yuvToRgba(vec3 yuv) {
-  vec3 yuvOffset = vec3(yuv.x - 0.0625, yuv.y - 0.5, yuv.z - 0.5);
-  return vec4(uColorTransform * yuvOffset, 1.0);
+  const vec3 yuvOffset = vec3(0.0625, 0.5, 0.5);
+  vec3 rgb = uYuvToRgbColorTransform * (yuv - yuvOffset);
+  return vec4(rgb, 1.0);
 }
 }
 
 
 void main() {
 void main() {

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

@@ -21,6 +21,7 @@ import android.content.Context;
 import android.opengl.GLES20;
 import android.opengl.GLES20;
 import android.opengl.Matrix;
 import android.opengl.Matrix;
 import android.util.Pair;
 import android.util.Pair;
+import androidx.media3.common.C;
 import androidx.media3.common.ColorInfo;
 import androidx.media3.common.ColorInfo;
 import androidx.media3.common.FrameProcessingException;
 import androidx.media3.common.FrameProcessingException;
 import androidx.media3.common.util.GlProgram;
 import androidx.media3.common.util.GlProgram;
@@ -64,12 +65,19 @@ import java.util.Arrays;
           new float[] {-1, 1, 0, 1},
           new float[] {-1, 1, 0, 1},
           new float[] {1, 1, 0, 1},
           new float[] {1, 1, 0, 1},
           new float[] {1, -1, 0, 1});
           new float[] {1, -1, 0, 1});
-  // Color transform coefficients from
-  // https://cs.android.com/android/platform/superproject/+/master:frameworks/av/media/libstagefright/colorconversion/ColorConverter.cpp;l=668-670;drc=487adf977a50cac3929eba15fad0d0f461c7ff0f.
-  private static final float[] MATRIX_YUV_TO_BT2020_COLOR_TRANSFORM = {
-    1.168f, 1.168f, 1.168f,
-    0.0f, -0.188f, 2.148f,
-    1.683f, -0.652f, 0.0f,
+
+  // YUV to RGB color transform coefficients can be calculated from the BT.2020 specification, by
+  // inverting the RGB to YUV equations, and scaling for limited range.
+  // https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.2020-2-201510-I!!PDF-E.pdf
+  private static final float[] BT2020_FULL_RANGE_YUV_TO_RGB_COLOR_TRANSFORM_MATRIX = {
+    1.0000f, 1.0000f, 1.0000f,
+    0.0000f, -0.1646f, 1.8814f,
+    1.4746f, -0.5714f, 0.0000f
+  };
+  private static final float[] BT2020_LIMITED_RANGE_YUV_TO_RGB_COLOR_TRANSFORM_MATRIX = {
+    1.1689f, 1.1689f, 1.1689f,
+    0.0000f, -0.1881f, 2.1502f,
+    1.6853f, -0.6530f, 0.0000f,
   };
   };
 
 
   /** The {@link MatrixTransformation MatrixTransformations} to apply. */
   /** The {@link MatrixTransformation MatrixTransformations} to apply. */
@@ -195,7 +203,12 @@ import java.util.Arrays;
       throw new FrameProcessingException(
       throw new FrameProcessingException(
           "The EXT_YUV_target extension is required for HDR editing input.");
           "The EXT_YUV_target extension is required for HDR editing input.");
     }
     }
-    glProgram.setFloatsUniform("uColorTransform", MATRIX_YUV_TO_BT2020_COLOR_TRANSFORM);
+    glProgram.setFloatsUniform(
+        "uYuvToRgbColorTransform",
+        opticalColorInfo.colorRange == C.COLOR_RANGE_FULL
+            ? BT2020_FULL_RANGE_YUV_TO_RGB_COLOR_TRANSFORM_MATRIX
+            : BT2020_LIMITED_RANGE_YUV_TO_RGB_COLOR_TRANSFORM_MATRIX);
+
     // TODO(b/227624622): Implement PQ and gamma TFs, and use an @IntDef to select between HLG,
     // TODO(b/227624622): Implement PQ and gamma TFs, and use an @IntDef to select between HLG,
     //  PQ, and gamma, coming from opticalColorInfo.colorTransfer.
     //  PQ, and gamma, coming from opticalColorInfo.colorTransfer.