From beed1bd76e51adc8f6271cf2a773d6b5a067c37c Mon Sep 17 00:00:00 2001
From: tofunmi <tofunmi@google.com>
Date: Tue, 24 Oct 2023 07:36:22 -0700
Subject: [PATCH] Pass initial timestamp offset to EncodedSampleExporter

When transmuxing, we usually only need to offset the timestamp by the position of a mediaItem in a sequence.

Trim optimization introduces another type of offset: for the transmux of the second part of the video we need to offset the timestamps by the total duration already trancoded by transformer.

PiperOrigin-RevId: 576134656
---
 .../androidx/media3/transformer/EncodedSampleExporter.java | 7 +++++--
 .../androidx/media3/transformer/TransformerInternal.java   | 3 ++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/EncodedSampleExporter.java b/libraries/transformer/src/main/java/androidx/media3/transformer/EncodedSampleExporter.java
index f32268f07d..f0c0e8b1ac 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/EncodedSampleExporter.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/EncodedSampleExporter.java
@@ -33,6 +33,7 @@ import java.util.concurrent.atomic.AtomicLong;
   private static final int MAX_INPUT_BUFFER_COUNT = 10;
 
   private final Format format;
+  private final long initialTimestampOffsetUs;
   private final AtomicLong nextMediaItemOffsetUs;
   private final Queue<DecoderInputBuffer> availableInputBuffers;
   private final Queue<DecoderInputBuffer> pendingInputBuffers;
@@ -45,9 +46,11 @@ import java.util.concurrent.atomic.AtomicLong;
       Format format,
       TransformationRequest transformationRequest,
       MuxerWrapper muxerWrapper,
-      FallbackListener fallbackListener) {
+      FallbackListener fallbackListener,
+      long initialTimestampOffsetUs) {
     super(format, muxerWrapper);
     this.format = format;
+    this.initialTimestampOffsetUs = initialTimestampOffsetUs;
     nextMediaItemOffsetUs = new AtomicLong();
     availableInputBuffers = new ConcurrentLinkedDeque<>();
     ByteBuffer emptyBuffer = ByteBuffer.allocateDirect(0).order(ByteOrder.nativeOrder());
@@ -82,7 +85,7 @@ import java.util.concurrent.atomic.AtomicLong;
     if (inputBuffer.isEndOfStream()) {
       inputEnded = true;
     } else {
-      inputBuffer.timeUs += mediaItemOffsetUs;
+      inputBuffer.timeUs += mediaItemOffsetUs + initialTimestampOffsetUs;
       pendingInputBuffers.add(inputBuffer);
     }
     return true;
diff --git a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
index 454372804c..90771f496f 100644
--- a/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
+++ b/libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java
@@ -617,7 +617,8 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
               assetLoaderInputTracker.getAssetLoaderInputFormat(sequenceIndex, trackType),
               transformationRequest,
               muxerWrapper,
-              fallbackListener));
+              fallbackListener,
+              videoSampleTimestampOffsetUs));
     }
 
     /**