Effects: Allow BT2020 colors with SDR transfers

Previously, I assumed that SDR contents must be BT709, and HDR contents must be
BT2020. Turns out BT2020 is just wide-gamut, and SDR contents / transfers may be
represented in BT2020 color spaces.

Relax the check, so that we don't throw when valid BT2020 SMPTE 170M contents
are input into effects.

PiperOrigin-RevId: 526668347

library/common/src/main/java/com/google/android/exoplayer2/C.java

@@ -1065,8 +1065,8 @@ public final class C {
 
 
   // LINT.IfChange(color_space)
   // LINT.IfChange(color_space)
   /**
   /**
-   * Video colorspaces. One of {@link Format#NO_VALUE}, {@link #COLOR_SPACE_BT601}, {@link
-   * #COLOR_SPACE_BT709} or {@link #COLOR_SPACE_BT2020}.
+   * Video color spaces, also referred to as color standards. One of {@link Format#NO_VALUE}, {@link
+   * #COLOR_SPACE_BT601}, {@link #COLOR_SPACE_BT709} or {@link #COLOR_SPACE_BT2020}.
    */
    */
   @Documented
   @Documented
   @Retention(RetentionPolicy.SOURCE)
   @Retention(RetentionPolicy.SOURCE)

library/effect/src/main/java/com/google/android/exoplayer2/effect/DefaultShaderProgram.java

@@ -365,9 +365,6 @@ import java.util.List;
       glProgram.setIntUniform("uOutputColorTransfer", outputColorTransfer);
       glProgram.setIntUniform("uOutputColorTransfer", outputColorTransfer);
     } else {
     } else {
       glProgram.setIntUniform("uEnableColorTransfer", enableColorTransfers ? GL_TRUE : GL_FALSE);
       glProgram.setIntUniform("uEnableColorTransfer", enableColorTransfers ? GL_TRUE : GL_FALSE);
-      checkArgument(
-          outputColorInfo.colorSpace != C.COLOR_SPACE_BT2020,
-          "Converting from SDR to HDR is not supported.");
       checkArgument(inputColorInfo.colorSpace == outputColorInfo.colorSpace);
       checkArgument(inputColorInfo.colorSpace == outputColorInfo.colorSpace);
       checkArgument(
       checkArgument(
           outputColorTransfer == C.COLOR_TRANSFER_SDR
           outputColorTransfer == C.COLOR_TRANSFER_SDR

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/AndroidTestUtil.java

@@ -101,6 +101,22 @@ public final class AndroidTestUtil {
           .setCodecs("avc1.64000D")
           .setCodecs("avc1.64000D")
           .build();
           .build();
 
 
+  public static final String MP4_ASSET_BT2020_SDR = "asset:///media/mp4/bt2020-sdr.mp4";
+  public static final Format MP4_ASSET_BT2020_SDR_FORMAT =
+      new Format.Builder()
+          .setSampleMimeType(VIDEO_H264)
+          .setWidth(3840)
+          .setHeight(2160)
+          .setFrameRate(29.822f)
+          .setColorInfo(
+              new ColorInfo.Builder()
+                  .setColorSpace(C.COLOR_SPACE_BT2020)
+                  .setColorRange(C.COLOR_RANGE_LIMITED)
+                  .setColorTransfer(C.COLOR_TRANSFER_SDR)
+                  .build())
+          .setCodecs("avc1.640033")
+          .build();
+
   public static final String MP4_ASSET_1080P_5_SECOND_HLG10 = "asset:///media/mp4/hlg-1080p.mp4";
   public static final String MP4_ASSET_1080P_5_SECOND_HLG10 = "asset:///media/mp4/hlg-1080p.mp4";
   public static final Format MP4_ASSET_1080P_5_SECOND_HLG10_FORMAT =
   public static final Format MP4_ASSET_1080P_5_SECOND_HLG10_FORMAT =
       new Format.Builder()
       new Format.Builder()

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/mh/ExportTest.java

@@ -17,6 +17,8 @@ package com.google.android.exoplayer2.transformer.mh;
 
 
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_4K60_PORTRAIT_FORMAT;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_4K60_PORTRAIT_FORMAT;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_4K60_PORTRAIT_URI_STRING;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_4K60_PORTRAIT_URI_STRING;
+import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_BT2020_SDR;
+import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_BT2020_SDR_FORMAT;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_SEF_URI_STRING;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_SEF_URI_STRING;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_URI_STRING;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_URI_STRING;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_WITH_INCREASING_TIMESTAMPS_FORMAT;
 import static com.google.android.exoplayer2.transformer.AndroidTestUtil.MP4_ASSET_WITH_INCREASING_TIMESTAMPS_FORMAT;
@@ -253,4 +255,29 @@ public class ExportTest {
         .build()
         .build()
         .run(testId, editedMediaItem);
         .run(testId, editedMediaItem);
   }
   }
+
+  @Test
+  public void exportTranscodeBt2020Sdr() throws Exception {
+    String testId = TAG + "exportBt2020Sdr";
+    Context context = ApplicationProvider.getApplicationContext();
+    if (AndroidTestUtil.skipAndLogIfFormatsUnsupported(
+        context,
+        testId,
+        /* inputFormat= */ MP4_ASSET_BT2020_SDR_FORMAT,
+        /* outputFormat= */ null)) {
+      return;
+    }
+
+    Transformer transformer = new Transformer.Builder(context).build();
+    MediaItem mediaItem = MediaItem.fromUri(Uri.parse(MP4_ASSET_BT2020_SDR));
+    ImmutableList<Effect> videoEffects =
+        ImmutableList.of(new ScaleAndRotateTransformation.Builder().setRotationDegrees(45).build());
+    Effects effects = new Effects(/* audioProcessors= */ ImmutableList.of(), videoEffects);
+    EditedMediaItem editedMediaItem =
+        new EditedMediaItem.Builder(mediaItem).setEffects(effects).build();
+
+    new TransformerAndroidTestRunner.Builder(context, transformer)
+        .build()
+        .run(testId, editedMediaItem);
+  }
 }
 }