Tests that illustrate ambiguous spec scenarios and Chromium's behavior

media/filters/source_buffer_stream_unittest.cc

Index: media/filters/source_buffer_stream_unittest.cc
diff --git a/media/filters/source_buffer_stream_unittest.cc b/media/filters/source_buffer_stream_unittest.cc
index 3828d6c02ec74cfa7f45401a458f1d57b9639e57..d0a03095397851bce396c96c93b3503476fe6968 100644
--- a/media/filters/source_buffer_stream_unittest.cc
+++ b/media/filters/source_buffer_stream_unittest.cc
@@ -3941,6 +3941,54 @@ TEST_F(SourceBufferStreamTest, BFrames) {
   CheckNoNextBuffer();
 }
 
+TEST_F(SourceBufferStreamTest, Video_DependencyInterrupted) {
+  NewSegmentAppend("0D30K 30");
+  CheckExpectedRangesByTimestamp("{ [0,60) }");
+  NewSegmentAppend("10D15K");
+
+  // Spec lack of clarity:
+  // The problem is the buffer at time 30 might be decoded *after* 10K has
+  // interrupted the decode dependency on 0K.
+  // If this test passes, then at least Chromium seems to be sane, though spec
+  // is ambiguous.
+  CheckExpectedRangesByTimestamp("{ [0,25) }");
+
+  // Seeking here to possibly prevent SBS track_buffer_ from interfering.
+  Seek(0);
+
+  CheckExpectedBuffers("0K 10K");
+  CheckNoNextBuffer();
+}
+
+TEST_F(SourceBufferStreamTest, Video_OverlappedFrameDurationShouldChange) {
+  NewSegmentAppend("0D30K");
+  NewSegmentAppend("100D30K");
+  CheckExpectedRangesByTimestamp("{ [0,30) [100,130) }");
+  NewSegmentAppend("10D15K");
+  CheckExpectedRangesByTimestamp("{ [0,25) [100,130) }");
+
+  RemoveInMs(10, 25, 130);
+
+  // Spec lack of clarity, and Chromium likely exhibiting bad behavior:
+  // The problem is the removal of the overlapping buffer [10, 15) exposes the
+  // frame end time of the remaining last buffer in the first range, which the
+  // spec doesn't say should have been reduced as part of this overlap. Hence,
+  // due to the remove operation, the buffered duration of the range
+  // *increases*. This is probably wrong in both spec and implementation.
+  // tl;dr: Shouldn't it be "{ [0, 10) [100, 130) }" here?
+  CheckExpectedRangesByTimestamp("{ [0,30) [100,130) }");
+
+  // Seeking here to possibly prevent SBS track_buffer_ from interfering.
+  Seek(0);
+
+  CheckExpectedBuffers("0K");
+  CheckNoNextBuffer();
+
+  SeekToTimestamp(base::TimeDelta::FromMilliseconds(100));
+  CheckExpectedBuffers("100K");
+  CheckNoNextBuffer();
+}
+
 // TODO(vrk): Add unit tests where keyframes are unaligned between streams.
 // (crbug.com/133557)