Fix timestamp rounding error in fMP4 extractor.

The sample timestamps are currently rounded to milliseconds, only to
be multiplied by 1000 later. This causes rounding errors where the sample
timestamps don't match the timestamps in the seek table (which are already
in microseconds).

issue:#7086
PiperOrigin-RevId: 307630559

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/FragmentedMp4Extractor.java

@@ -962,20 +962,20 @@ private static int parseTrun(
 
     // Offset to the entire video timeline. In the presence of B-frames this is usually used to
     // ensure that the first frame's presentation timestamp is zero.
-    long edtsOffset = 0;
+    long edtsOffsetUs = 0;
 
     // Currently we only support a single edit that moves the entire media timeline (indicated by
     // duration == 0). Other uses of edit lists are uncommon and unsupported.
     if (track.editListDurations != null && track.editListDurations.length == 1
         && track.editListDurations[0] == 0) {
-      edtsOffset =
+      edtsOffsetUs =
           Util.scaleLargeTimestamp(
-              track.editListMediaTimes[0], C.MILLIS_PER_SECOND, track.timescale);
+              track.editListMediaTimes[0], C.MICROS_PER_SECOND, track.timescale);
     }
 
     int[] sampleSizeTable = fragment.sampleSizeTable;
-    int[] sampleCompositionTimeOffsetTable = fragment.sampleCompositionTimeOffsetTable;
-    long[] sampleDecodingTimeTable = fragment.sampleDecodingTimeTable;
+    int[] sampleCompositionTimeOffsetUsTable = fragment.sampleCompositionTimeOffsetUsTable;
+    long[] sampleDecodingTimeUsTable = fragment.sampleDecodingTimeUsTable;
     boolean[] sampleIsSyncFrameTable = fragment.sampleIsSyncFrameTable;
 
     boolean workaroundEveryVideoFrameIsSyncFrame = track.type == C.TRACK_TYPE_VIDEO
@@ -999,13 +999,13 @@ private static int parseTrun(
         // here, because unsigned integers will still be parsed correctly (unless their top bit is
         // set, which is never true in practice because sample offsets are always small).
         int sampleOffset = trun.readInt();
-        sampleCompositionTimeOffsetTable[i] =
-            (int) ((sampleOffset * C.MILLIS_PER_SECOND) / timescale);
+        sampleCompositionTimeOffsetUsTable[i] =
+            (int) ((sampleOffset * C.MICROS_PER_SECOND) / timescale);
       } else {
-        sampleCompositionTimeOffsetTable[i] = 0;
+        sampleCompositionTimeOffsetUsTable[i] = 0;
       }
-      sampleDecodingTimeTable[i] =
-          Util.scaleLargeTimestamp(cumulativeTime, C.MILLIS_PER_SECOND, timescale) - edtsOffset;
+      sampleDecodingTimeUsTable[i] =
+          Util.scaleLargeTimestamp(cumulativeTime, C.MICROS_PER_SECOND, timescale) - edtsOffsetUs;
       sampleSizeTable[i] = sampleSize;
       sampleIsSyncFrameTable[i] = ((sampleFlags >> 16) & 0x1) == 0
           && (!workaroundEveryVideoFrameIsSyncFrame || i == 0);
@@ -1291,7 +1291,7 @@ private boolean readSample(ExtractorInput input) throws IOException, Interrupted
     Track track = currentTrackBundle.track;
     TrackOutput output = currentTrackBundle.output;
     int sampleIndex = currentTrackBundle.currentSampleIndex;
-    long sampleTimeUs = fragment.getSamplePresentationTime(sampleIndex) * 1000L;
+    long sampleTimeUs = fragment.getSamplePresentationTimeUs(sampleIndex);
     if (timestampAdjuster != null) {
       sampleTimeUs = timestampAdjuster.adjustSampleTimestamp(sampleTimeUs);
     }
@@ -1535,10 +1535,9 @@ public void reset() {
      * @param timeUs The seek time, in microseconds.
      */
     public void seek(long timeUs) {
-      long timeMs = C.usToMs(timeUs);
       int searchIndex = currentSampleIndex;
       while (searchIndex < fragment.sampleCount
-          && fragment.getSamplePresentationTime(searchIndex) < timeMs) {
+          && fragment.getSamplePresentationTimeUs(searchIndex) < timeUs) {
         if (fragment.sampleIsSyncFrameTable[searchIndex]) {
           firstSampleToOutputIndex = searchIndex;
         }

library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/TrackFragment.java

@@ -60,14 +60,10 @@
    * The size of each sample in the fragment.
    */
   public int[] sampleSizeTable;
-  /**
-   * The composition time offset of each sample in the fragment.
-   */
-  public int[] sampleCompositionTimeOffsetTable;
-  /**
-   * The decoding time of each sample in the fragment.
-   */
-  public long[] sampleDecodingTimeTable;
+  /** The composition time offset of each sample in the fragment, in microseconds. */
+  public int[] sampleCompositionTimeOffsetUsTable;
+  /** The decoding time of each sample in the fragment, in microseconds. */
+  public long[] sampleDecodingTimeUsTable;
   /**
    * Indicates which samples are sync frames.
    */
@@ -139,8 +135,8 @@ public void initTables(int trunCount, int sampleCount) {
       // likely. The choice of 25% is relatively arbitrary.
       int tableSize = (sampleCount * 125) / 100;
       sampleSizeTable = new int[tableSize];
-      sampleCompositionTimeOffsetTable = new int[tableSize];
-      sampleDecodingTimeTable = new long[tableSize];
+      sampleCompositionTimeOffsetUsTable = new int[tableSize];
+      sampleDecodingTimeUsTable = new long[tableSize];
       sampleIsSyncFrameTable = new boolean[tableSize];
       sampleHasSubsampleEncryptionTable = new boolean[tableSize];
     }
@@ -186,8 +182,14 @@ public void fillEncryptionData(ParsableByteArray source) {
     sampleEncryptionDataNeedsFill = false;
   }
 
-  public long getSamplePresentationTime(int index) {
-    return sampleDecodingTimeTable[index] + sampleCompositionTimeOffsetTable[index];
+  /**
+   * Returns the sample presentation timestamp in microseconds.
+   *
+   * @param index The sample index.
+   * @return The presentation timestamps of this sample in microseconds.
+   */
+  public long getSamplePresentationTimeUs(int index) {
+    return sampleDecodingTimeUsTable[index] + sampleCompositionTimeOffsetUsTable[index];
   }
 
   /** Returns whether the sample at the given index has a subsample encryption table. */

library/core/src/test/assets/mp4/sample_ac4_fragmented.mp4.0.dump

@@ -81,7 +81,7 @@ track 0:
     flags = 1
     data = length 520, hash FEE56928
   sample 13:
-    time = 520000
+    time = 519999
     flags = 1
     data = length 599, hash 41F496C5
   sample 14:

library/core/src/test/assets/mp4/sample_ac4_fragmented.mp4.1.dump

@@ -57,7 +57,7 @@ track 0:
     flags = 1
     data = length 520, hash FEE56928
   sample 7:
-    time = 520000
+    time = 519999
     flags = 1
     data = length 599, hash 41F496C5
   sample 8:

library/core/src/test/assets/mp4/sample_ac4_fragmented.mp4.2.dump

@@ -33,7 +33,7 @@ track 0:
     flags = 1
     data = length 520, hash FEE56928
   sample 1:
-    time = 520000
+    time = 519999
     flags = 1
     data = length 599, hash 41F496C5
   sample 2:

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.0.dump

@@ -107,7 +107,7 @@ track 0:
     crypto mode = 1
     encryption key = length 16, hash 9FDDEA52
   sample 13:
-    time = 520000
+    time = 519999
     flags = 1073741825
     data = length 616, hash 3F657E23
     crypto mode = 1

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.1.dump

@@ -71,7 +71,7 @@ track 0:
     crypto mode = 1
     encryption key = length 16, hash 9FDDEA52
   sample 7:
-    time = 520000
+    time = 519999
     flags = 1073741825
     data = length 616, hash 3F657E23
     crypto mode = 1

library/core/src/test/assets/mp4/sample_ac4_protected.mp4.2.dump

@@ -35,7 +35,7 @@ track 0:
     crypto mode = 1
     encryption key = length 16, hash 9FDDEA52
   sample 1:
-    time = 520000
+    time = 519999
     flags = 1073741825
     data = length 616, hash 3F657E23
     crypto mode = 1