From 0afe5923d87a86502cfd407e2e336eca9c75a3f3 Mon Sep 17 00:00:00 2001
From: kimvde <kimvde@google.com>
Date: Fri, 24 Feb 2023 16:40:51 +0000
Subject: [PATCH] Clarify some threading requirements.

PiperOrigin-RevId: 512079471
---
 .../main/java/androidx/media3/transformer/AssetLoader.java    | 4 ++--
 .../androidx/media3/transformer/CompositeAssetLoader.java     | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/AssetLoader.java b/libraries/transformer/src/main/java/androidx/media3/transformer/AssetLoader.java
index 5a17090c6b..700b620486 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/AssetLoader.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/AssetLoader.java
@@ -92,8 +92,8 @@ public interface AssetLoader {
      * <p>Must be called once per {@linkplain #onTrackCount(int) declared} track.
      *
      * <p>Must be called from the thread that will be used to call the returned {@link
-     * SampleConsumer}'s methods. This thread is generally different from the one used to access the
-     * {@link AssetLoader} methods.
+     * SampleConsumer}'s methods. This thread must be the same for all the tracks added, and is
+     * generally different from the one used to access the {@link AssetLoader} methods.
      *
      * @param format The {@link Format} of the input media (prior to video slow motion flattening or
      *     to decoding).
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java b/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
index 900b20188b..430f640a6e 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/CompositeAssetLoader.java
@@ -146,7 +146,7 @@ import java.util.concurrent.atomic.AtomicInteger;
    *
    * <p>There can't be more than one {@link OnMediaItemChangedListener} for the same track type.
    *
-   * <p>Can be called from any thread.
+   * <p>Must always be called from the same thread. This thread can be any thread.
    *
    * @param onMediaItemChangedListener The {@link OnMediaItemChangedListener}.
    * @param trackType The {@link C.TrackType} for which to listen to {@link MediaItem} change