Return EOS when selected_range_ is NULL in SourceBufferStream

Fixes the issue where an OnSetDuration call truncates the selected_range_ and resets the
next_buffer_position. kEndOfStream is now returned instead of kNeedBuffer from
GetNextBufferInternal when selected_ranges_ is NULL.

BUG=484992

Review URL: https://codereview.chromium.org/1119163005

Cr-Commit-Position: refs/heads/master@{#329753}

media/filters/source_buffer_stream.cc

@@ -928,7 +928,7 @@ void SourceBufferStream::Seek(base::TimeDelta timestamp) {
 }
 
 bool SourceBufferStream::IsSeekPending() const {
-  return !(end_of_stream_ && IsEndSelected()) && seek_pending_;
+  return seek_pending_ && !IsEndOfStreamReached();
 }
 
 void SourceBufferStream::OnSetDuration(base::TimeDelta duration) {
@@ -1098,9 +1098,11 @@ SourceBufferStream::Status SourceBufferStream::GetNextBufferInternal(
     return kSuccess;
   }
 
+  DCHECK(track_buffer_.empty());
   if (!selected_range_ || !selected_range_->HasNextBuffer()) {
-    if (end_of_stream_ && IsEndSelected())
+    if (IsEndOfStreamReached()) {
       return kEndOfStream;
+    }
     DVLOG(3) << __FUNCTION__ << " " << GetStreamTypeName()
              << ": returning kNeedBuffer "
              << (selected_range_ ? "(selected range has no next buffer)"
@@ -1205,7 +1207,10 @@ void SourceBufferStream::UnmarkEndOfStream() {
   end_of_stream_ = false;
 }
 
-bool SourceBufferStream::IsEndSelected() const {
+bool SourceBufferStream::IsEndOfStreamReached() const {
+  if (!end_of_stream_ || !track_buffer_.empty())
+    return false;
+
   if (ranges_.empty())
     return true;
 
@@ -1215,6 +1220,9 @@ bool SourceBufferStream::IsEndSelected() const {
     return seek_buffer_timestamp_ >= last_range_end_time;
   }
 
+  if (!selected_range_)
+    return true;
+
   return selected_range_ == ranges_.back();
 }
 

media/filters/source_buffer_stream.h

@@ -275,9 +275,12 @@ class MEDIA_EXPORT SourceBufferStream {
   // stream, and "TEXT" for a text stream.
   std::string GetStreamTypeName() const;
 
-  // Returns true if we don't have any ranges or the last range is selected
-  // or there is a pending seek beyond any existing ranges.
-  bool IsEndSelected() const;
+  // Returns true if end of stream has been reached, i.e. the
+  // following conditions are met:
+  // 1. end of stream is marked and there is nothing in the track_buffer.
+  // 2. We don't have any ranges, or the last or no range is selected,
+  //    or there is a pending seek beyond any existing ranges.
+  bool IsEndOfStreamReached() const;
 
   // Deletes the range pointed to by |*itr| and removes it from |ranges_|.
   // If |*itr| points to |selected_range_|, then |selected_range_| is set to

media/filters/source_buffer_stream_unittest.cc

@@ -349,6 +349,12 @@ class SourceBufferStreamTest : public testing::Test {
     EXPECT_EQ(SourceBufferStream::kNeedBuffer, stream_->GetNextBuffer(&buffer));
   }
 
+  void CheckEOSReached() {
+    scoped_refptr<StreamParserBuffer> buffer;
+    EXPECT_EQ(SourceBufferStream::kEndOfStream,
+              stream_->GetNextBuffer(&buffer));
+  }
+
   void CheckVideoConfig(const VideoDecoderConfig& config) {
     const VideoDecoderConfig& actual = stream_->GetCurrentVideoDecoderConfig();
     EXPECT_TRUE(actual.Matches(config))
@@ -3239,6 +3245,55 @@ TEST_F(SourceBufferStreamTest,
   CheckExpectedRangesByTimestamp("{ [0,90) }");
 }
 
+TEST_F(SourceBufferStreamTest, SetExplicitDuration_MarkEOS) {
+  // Append 1 buffer at positions 0 through 8.
+  NewSegmentAppend(0, 9);
+
+  // Check expected ranges.
+  CheckExpectedRanges("{ [0,8) }");
+
+  // Seek to 5.
+  Seek(5);
+
+  // Set duration to be before the seeked to position.
+  // This will result in truncation of the selected range and a reset
+  // of NextBufferPosition.
+  stream_->OnSetDuration(frame_duration() * 4);
+
+  // Check the expected ranges.
+  CheckExpectedRanges("{ [0,3) }");
+
+  // Mark EOS reached.
+  stream_->MarkEndOfStream();
+
+  // Expect EOS to be reached.
+  CheckEOSReached();
+}
+
+TEST_F(SourceBufferStreamTest, SetExplicitDuration_MarkEOS_IsSeekPending) {
+  // Append 1 buffer at positions 0 through 8.
+  NewSegmentAppend(0, 9);
+
+  // Check expected ranges.
+  CheckExpectedRanges("{ [0,8) }");
+
+  // Seek to 9 which will result in a pending seek.
+  Seek(9);
+
+  // Set duration to be before the seeked to position.
+  // This will result in truncation of the selected range and a reset
+  // of NextBufferPosition.
+  stream_->OnSetDuration(frame_duration() * 4);
+
+  // Check the expected ranges.
+  CheckExpectedRanges("{ [0,3) }");
+
+  EXPECT_TRUE(stream_->IsSeekPending());
+  // Mark EOS reached.
+  stream_->MarkEndOfStream();
+  EXPECT_FALSE(stream_->IsSeekPending());
+}
+
 // Test the case were the current playback position is at the end of the
 // buffered data and several overlaps occur that causes the selected
 // range to get split and then merged back into a single range.