Add more SeekMap assertions, and "fix" MatroskaExtractor

In MatroskaExtractor, if the last cue time exceeds the duration
specified in the header, then we end up generating a negative
duration chunk as the last item in the SeekMap. We should probably
not do this, so drop it instead.

Note: Matroska does have a CueDuration element, but it's not used
in the one problematic file I've found.
PiperOrigin-RevId: 285738418

library/core/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java

@@ -1635,6 +1635,16 @@ public class MatroskaExtractor implements Extractor {
     sizes[cuePointsSize - 1] =
         (int) (segmentContentPosition + segmentContentSize - offsets[cuePointsSize - 1]);
     durationsUs[cuePointsSize - 1] = durationUs - timesUs[cuePointsSize - 1];
+
+    long lastDurationUs = durationsUs[cuePointsSize - 1];
+    if (lastDurationUs <= 0) {
+      Log.w(TAG, "Discarding last cue point with unexpected duration: " + lastDurationUs);
+      sizes = Arrays.copyOf(sizes, sizes.length - 1);
+      offsets = Arrays.copyOf(offsets, offsets.length - 1);
+      durationsUs = Arrays.copyOf(durationsUs, durationsUs.length - 1);
+      timesUs = Arrays.copyOf(timesUs, timesUs.length - 1);
+    }
+
     cueTimesUs = null;
     cueClusterPositions = null;
     return new ChunkIndex(sizes, offsets, durationsUs, timesUs);

library/core/src/test/assets/mkv/sample.mkv.0.dump

@@ -1,6 +1,6 @@
 seekMap:
   isSeekable = true
-  duration = 1072000
+  duration = 1104000
   getPosition(0) = [[timeUs=67000, position=5576]]
 numberOfTracks = 2
 track 1:

library/core/src/test/assets/mkv/sample.mkv.1.dump

@@ -1,6 +1,6 @@
 seekMap:
   isSeekable = true
-  duration = 1072000
+  duration = 1104000
   getPosition(0) = [[timeUs=67000, position=5576]]
 numberOfTracks = 2
 track 1:
@@ -28,93 +28,85 @@ track 1:
     initializationData:
       data = length 30, hash F6F3D010
       data = length 10, hash 7A0D0F2B
-  total output bytes = 30995
-  sample count = 22
+  total output bytes = 29422
+  sample count = 20
   sample 0:
-    time = 334000
-    flags = 0
-    data = length 953, hash 7160C661
-  sample 1:
-    time = 300000
-    flags = 0
-    data = length 620, hash 7A7AE07C
-  sample 2:
     time = 367000
     flags = 0
     data = length 405, hash 5CC7F4E7
-  sample 3:
+  sample 1:
     time = 500000
     flags = 0
     data = length 4852, hash 9DB6979D
-  sample 4:
+  sample 2:
     time = 467000
     flags = 0
     data = length 547, hash E31A6979
-  sample 5:
+  sample 3:
     time = 434000
     flags = 0
     data = length 570, hash FEC40D00
-  sample 6:
+  sample 4:
     time = 634000
     flags = 0
     data = length 5525, hash 7C478F7E
-  sample 7:
+  sample 5:
     time = 567000
     flags = 0
     data = length 1082, hash DA07059A
-  sample 8:
+  sample 6:
     time = 534000
     flags = 0
     data = length 807, hash 93478E6B
-  sample 9:
+  sample 7:
     time = 600000
     flags = 0
     data = length 744, hash 9A8E6026
-  sample 10:
+  sample 8:
     time = 767000
     flags = 0
     data = length 4732, hash C73B23C0
-  sample 11:
+  sample 9:
     time = 700000
     flags = 0
     data = length 1004, hash 8A19A228
-  sample 12:
+  sample 10:
     time = 667000
     flags = 0
     data = length 794, hash 8126022C
-  sample 13:
+  sample 11:
     time = 734000
     flags = 0
     data = length 645, hash F08300E5
-  sample 14:
+  sample 12:
     time = 900000
     flags = 0
     data = length 2684, hash 727FE378
-  sample 15:
+  sample 13:
     time = 834000
     flags = 0
     data = length 787, hash 419A7821
-  sample 16:
+  sample 14:
     time = 800000
     flags = 0
     data = length 649, hash 5C159346
-  sample 17:
+  sample 15:
     time = 867000
     flags = 0
     data = length 509, hash F912D655
-  sample 18:
+  sample 16:
     time = 1034000
     flags = 0
     data = length 1226, hash 29815C21
-  sample 19:
+  sample 17:
     time = 967000
     flags = 0
     data = length 898, hash D997AD0A
-  sample 20:
+  sample 18:
     time = 934000
     flags = 0
     data = length 476, hash A0423645
-  sample 21:
+  sample 19:
     time = 1000000
     flags = 0
     data = length 486, hash DDF32CBB

library/core/src/test/assets/mkv/sample.mkv.2.dump

@@ -1,6 +1,6 @@
 seekMap:
   isSeekable = true
-  duration = 1072000
+  duration = 1104000
   getPosition(0) = [[timeUs=67000, position=5576]]
 numberOfTracks = 2
 track 1:
@@ -28,49 +28,41 @@ track 1:
     initializationData:
       data = length 30, hash F6F3D010
       data = length 10, hash 7A0D0F2B
-  total output bytes = 10158
-  sample count = 11
+  total output bytes = 8360
+  sample count = 9
   sample 0:
-    time = 700000
-    flags = 0
-    data = length 1004, hash 8A19A228
-  sample 1:
-    time = 667000
-    flags = 0
-    data = length 794, hash 8126022C
-  sample 2:
     time = 734000
     flags = 0
     data = length 645, hash F08300E5
-  sample 3:
+  sample 1:
     time = 900000
     flags = 0
     data = length 2684, hash 727FE378
-  sample 4:
+  sample 2:
     time = 834000
     flags = 0
     data = length 787, hash 419A7821
-  sample 5:
+  sample 3:
     time = 800000
     flags = 0
     data = length 649, hash 5C159346
-  sample 6:
+  sample 4:
     time = 867000
     flags = 0
     data = length 509, hash F912D655
-  sample 7:
+  sample 5:
     time = 1034000
     flags = 0
     data = length 1226, hash 29815C21
-  sample 8:
+  sample 6:
     time = 967000
     flags = 0
     data = length 898, hash D997AD0A
-  sample 9:
+  sample 7:
     time = 934000
     flags = 0
     data = length 476, hash A0423645
-  sample 10:
+  sample 8:
     time = 1000000
     flags = 0
     data = length 486, hash DDF32CBB

library/core/src/test/assets/mkv/sample.mkv.3.dump

@@ -1,6 +1,6 @@
 seekMap:
   isSeekable = true
-  duration = 1072000
+  duration = 1104000
   getPosition(0) = [[timeUs=67000, position=5576]]
 numberOfTracks = 2
 track 1:

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeExtractorOutput.java

@@ -70,8 +70,18 @@ public final class FakeExtractorOutput implements ExtractorOutput, Dumper.Dumpab
 
   @Override
   public void seekMap(SeekMap seekMap) {
-    if (seekMap.isSeekable() && seekMap.getDurationUs() == C.TIME_UNSET) {
-      throw new IllegalStateException("SeekMap cannot be seekable and have an unknown duration");
+    if (seekMap.isSeekable()) {
+      if (seekMap.getDurationUs() == C.TIME_UNSET) {
+        throw new IllegalStateException("SeekMap cannot be seekable and have an unknown duration");
+      }
+      SeekMap.SeekPoints seekPoints = seekMap.getSeekPoints(0);
+      if (!seekPoints.first.equals(seekPoints.second)) {
+        throw new IllegalStateException("SeekMap defines two seek points for t=0");
+      }
+      seekPoints = seekMap.getSeekPoints(seekMap.getDurationUs());
+      if (!seekPoints.first.equals(seekPoints.second)) {
+        throw new IllegalStateException("SeekMap defines two seek points for t=durationUs");
+      }
     }
     this.seekMap = seekMap;
   }