From 3c4ee51e10fe0a2ea495f00a3fcd98d6cb83b561 Mon Sep 17 00:00:00 2001
From: andrewlewis <andrewlewis@google.com>
Date: Wed, 3 Aug 2022 16:06:45 +0000
Subject: [PATCH] Avoid encoder default color info when tone-mapping

The encoder color info [defaults](https://cs.android.com/android/platform/superproject/+/master:frameworks/av/media/libstagefright/foundation/ColorUtils.cpp;l=377;drc=891c19ccfa4953b5e5f7b87118e007b994d8074c) to a value that depends on the input resolution, but when tone-mapping is enabled we should always get BT.709 color space. Hard-code this constant for now to avoid behavior depending on the resolution. A future change should use the decoder output media format to populate the color info.

PiperOrigin-RevId: 465070378
---
 .../src/main/java/androidx/media3/common/ColorInfo.java  | 9 +++++++++
 .../transformer/VideoTranscodingSamplePipeline.java      | 7 ++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/libraries/common/src/main/java/androidx/media3/common/ColorInfo.java b/libraries/common/src/main/java/androidx/media3/common/ColorInfo.java
index db10f7f4b9..a4b871a64f 100644
--- a/libraries/common/src/main/java/androidx/media3/common/ColorInfo.java
+++ b/libraries/common/src/main/java/androidx/media3/common/ColorInfo.java
@@ -31,6 +31,15 @@ import org.checkerframework.dataflow.qual.Pure;
 /** Stores color info. */
 @UnstableApi
 public final class ColorInfo implements Bundleable {
+
+  /** Color info representing SDR BT.709 limited range, which is a common SDR video color format. */
+  public static final ColorInfo SDR_BT709_LIMITED =
+      new ColorInfo(
+          C.COLOR_SPACE_BT709,
+          C.COLOR_RANGE_LIMITED,
+          C.COLOR_TRANSFER_SDR,
+          /* hdrStaticInfo= */ null);
+
   /**
    * Returns the {@link C.ColorSpace} corresponding to the given ISO color primary code, as per
    * table A.7.21.1 in Rec. ITU-T T.832 (03/2009), or {@link Format#NO_VALUE} if no mapping can be
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/VideoTranscodingSamplePipeline.java b/libraries/transformer/src/main/java/androidx/media3/transformer/VideoTranscodingSamplePipeline.java
index f48046c5b6..9032f62256 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/VideoTranscodingSamplePipeline.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/VideoTranscodingSamplePipeline.java
@@ -384,6 +384,11 @@ import org.checkerframework.dataflow.qual.Pure;
       }
 
       boolean isInputToneMapped = ColorInfo.isHdr(inputFormat.colorInfo) && !isHdrEditingEnabled();
+      // When tone-mapping HDR to SDR is enabled, assume we get BT.709 to avoid having the encoder
+      // populate default color info, which depends on the resolution.
+      // TODO(b/237674316): Get the color info from the decoder output media format instead.
+      ColorInfo outputColorInfo =
+          isInputToneMapped ? ColorInfo.SDR_BT709_LIMITED : inputFormat.colorInfo;
       Format requestedEncoderFormat =
           new Format.Builder()
               .setWidth(requestedWidth)
@@ -391,7 +396,7 @@ import org.checkerframework.dataflow.qual.Pure;
               .setRotationDegrees(0)
               .setFrameRate(inputFormat.frameRate)
               .setSampleMimeType(requestedOutputMimeType)
-              .setColorInfo(isInputToneMapped ? null : inputFormat.colorInfo)
+              .setColorInfo(outputColorInfo)
               .build();
 
       encoder =