WIP - MSE: Drop non-keyframes that lack keyframe dependency

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 610e78d75866dcca5ada51b9333b61fdbf80f040..cd7faafae1ccd16bfb5b6027d1d62a3e9b63a9e6 100644
--- a/media/filters/source_buffer_stream_unittest.cc
+++ b/media/filters/source_buffer_stream_unittest.cc
@@ -4041,6 +4041,52 @@ TEST_F(SourceBufferStreamTest, RefinedDurationEstimates_FrontOverlap) {
   CheckNoNextBuffer();
 }
 
+TEST_F(SourceBufferStreamTest, LeadingNonKeyframes_Kept) {
+  // Append a media segment that begins with a keyframe.
+  NewSegmentAppend("0K 10D10");
+
+  // Append another (continuous) media segment that begins with non-keyframes.
+  NewSegmentAppend("20 30 40K 50 60D10");
+
+  CheckExpectedRangesByTimestamp("{ [0,70) }");
+  Seek(0);
+  CheckExpectedBuffers("0K 10D10 20 30 40K 50 60D10");
+  CheckNoNextBuffer();
+}
+
+TEST_F(SourceBufferStreamTest, LeadingNonKeyframes_Dropped) {
+  // Append a media segment that has some initial non-keyframes.
+  NewSegmentAppend("0 10 20 30K 40 50 60 70D10K");
+
+  CheckExpectedRangesByTimestamp("{ [30,80) }");
+  SeekToTimestamp(base::TimeDelta::FromMilliseconds(30));
+  CheckExpectedBuffers("30K 40 50 60 70K");
+  CheckNoNextBuffer();
+}
+
+TEST_F(SourceBufferStreamTest,
+       NonKeyframesDirectlyFollowingRemovedRange_Dropped) {
+  // Append a media segment containing decode dependencies for subsequent
+  // append.
+  NewSegmentAppend("0K 10 20 30 40D10K");
+  CheckExpectedRangesByTimestamp("{ [0,50) }");
+
+  // Remove the decode dependency that subsequent append will depend upon.
+  RemoveInMs(40, 41, 50);
+  CheckExpectedRangesByTimestamp("{ [0,40) }");
+
+  // Append more media, leading with non-keyframes that supposedly might have
+  // depended upon the now-removed keyframe from time 40ms.
+  AppendBuffers("50 60 70K 80D10");
+  CheckExpectedRangesByTimestamp("{ [0,40) [70,90) }");
+  Seek(0);
+  CheckExpectedBuffers("0K 10 20 30D10");
+  CheckNoNextBuffer();
+  SeekToTimestamp(base::TimeDelta::FromMilliseconds(70));
+  CheckExpectedBuffers("70K 80D10");
+  CheckNoNextBuffer();
+}
+
 // TODO(vrk): Add unit tests where keyframes are unaligned between streams.
 // (crbug.com/133557)