From eebe990d2059a04c645cf1c0fd254764ddb4c0bc Mon Sep 17 00:00:00 2001
From: olly <olly@google.com>
Date: Tue, 24 Mar 2020 11:31:19 +0000
Subject: [PATCH] MP4 edit lists: Use floor rather than ceil to find first
 sample

If the start time of the edit falls within a sample, start from that
sample rather than the next one. This ensures playback can start from
the correct point if the sample is a keyframe, rather than having to
start from the next one.

Issue: #7133
PiperOrigin-RevId: 302639115
---
 .../android/exoplayer2/extractor/mp4/AtomParsers.java | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
index 0c03795b8a..3cf858558a 100644
--- a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
+++ b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
@@ -446,10 +446,15 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
         long editDuration =
             Util.scaleLargeTimestamp(
                 track.editListDurations[i], track.timescale, track.movieTimescale);
-        startIndices[i] = Util.binarySearchCeil(timestamps, editMediaTime, true, true);
+        startIndices[i] =
+            Util.binarySearchFloor(
+                timestamps, editMediaTime, /* inclusive= */ true, /* stayInBounds= */ true);
         endIndices[i] =
             Util.binarySearchCeil(
-                timestamps, editMediaTime + editDuration, omitClippedSample, false);
+                timestamps,
+                editMediaTime + editDuration,
+                /* inclusive= */ omitClippedSample,
+                /* stayInBounds= */ false);
         while (startIndices[i] < endIndices[i]
             && (flags[startIndices[i]] & C.BUFFER_FLAG_KEY_FRAME) == 0) {
           // Applying the edit correctly would require prerolling from the previous sync sample. In
@@ -487,7 +492,7 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
         long ptsUs = Util.scaleLargeTimestamp(pts, C.MICROS_PER_SECOND, track.movieTimescale);
         long timeInSegmentUs =
             Util.scaleLargeTimestamp(
-                timestamps[j] - editMediaTime, C.MICROS_PER_SECOND, track.timescale);
+                Math.max(0, timestamps[j] - editMediaTime), C.MICROS_PER_SECOND, track.timescale);
         editedTimestamps[sampleIndex] = ptsUs + timeInSegmentUs;
         if (copyMetadata && editedSizes[sampleIndex] > editedMaximumSize) {
           editedMaximumSize = sizes[j];