MSE: Allow negative parsed frame PTS/DTS in FrameProcessor

r274473 did not remove sanity checks for negative PTS/DTS that occur
prior to any adjustment based on timestampOffset. Current MSE spec does
not call for issuing decode error if PTS or DTS are negative at the top
of the coded frame processing loop. This change removes the sanity
checks that are not spec-compliant.

R=acolwell@chromium.org
BUG=381114
TEST=FrameProcessorTest.AllowNegativeFramePTSAndDTSBeforeOffsetAdjustment

Review URL: https://codereview.chromium.org/334363006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@277903 0039d316-1c4b-4281-b951-d872f2087c98

media/filters/frame_processor.cc

@@ -107,14 +107,12 @@ bool FrameProcessor::ProcessFrame(
              << ", DUR=" << frame_duration.InSecondsF();
 
     // Sanity check the timestamps.
-    if (presentation_timestamp < base::TimeDelta()) {
-      DVLOG(2) << __FUNCTION__ << ": Negative or unknown frame PTS: "
-               << presentation_timestamp.InSecondsF();
+    if (presentation_timestamp == kNoTimestamp()) {
+      DVLOG(2) << __FUNCTION__ << ": Unknown frame PTS";
       return false;
     }
-    if (decode_timestamp < base::TimeDelta()) {
-      DVLOG(2) << __FUNCTION__ << ": Negative or unknown frame DTS: "
-               << decode_timestamp.InSecondsF();
+    if (decode_timestamp == kNoTimestamp()) {
+      DVLOG(2) << __FUNCTION__ << ": Unknown frame DTS";
       return false;
     }
     if (decode_timestamp > presentation_timestamp) {

media/filters/frame_processor_unittest.cc

@@ -607,6 +607,32 @@ TEST_P(FrameProcessorTest, AppendWindowFilterWithInexactPreroll) {
   CheckReadsThenReadStalls(audio_.get(), "0P 0:9.75 10:20");
 }
 
+TEST_P(FrameProcessorTest, AllowNegativeFramePTSAndDTSBeforeOffsetAdjustment) {
+  InSequence s;
+  AddTestTracks(HAS_AUDIO);
+  new_media_segment_ = true;
+  bool using_sequence_mode = GetParam();
+  if (using_sequence_mode) {
+    frame_processor_->SetSequenceMode(true);
+    EXPECT_CALL(callbacks_, PossibleDurationIncrease(frame_duration_ * 3));
+  } else {
+    EXPECT_CALL(callbacks_,
+                PossibleDurationIncrease((frame_duration_ * 5) / 2));
+  }
+
+  ProcessFrames("-5K 5K 15K", "");
+
+  if (using_sequence_mode) {
+    EXPECT_EQ(frame_duration_ / 2, timestamp_offset_);
+    CheckExpectedRangesByTimestamp(audio_.get(), "{ [0,30) }");
+    CheckReadsThenReadStalls(audio_.get(), "0:-5 10:5 20:15");
+  } else {
+    EXPECT_EQ(base::TimeDelta(), timestamp_offset_);
+    CheckExpectedRangesByTimestamp(audio_.get(), "{ [0,25) }");
+    CheckReadsThenReadStalls(audio_.get(), "0:-5 5 15");
+  }
+}
+
 INSTANTIATE_TEST_CASE_P(SequenceMode, FrameProcessorTest, Values(true));
 INSTANTIATE_TEST_CASE_P(SegmentsMode, FrameProcessorTest, Values(false));