Add gapless playback support for AAC playback.

media/filters/chunk_demuxer_unittest.cc

Index: media/filters/chunk_demuxer_unittest.cc
diff --git a/media/filters/chunk_demuxer_unittest.cc b/media/filters/chunk_demuxer_unittest.cc
index 55815c169026fcf5923fcef52bb495bed85fa221..22f62be8bf0fae4ccd6ec545a188bbb6025a76e7 100644
--- a/media/filters/chunk_demuxer_unittest.cc
+++ b/media/filters/chunk_demuxer_unittest.cc
@@ -867,7 +867,10 @@ class ChunkDemuxerTest : public ::testing::TestWithParam<bool> {
     base::SplitString(expected, ' ', &timestamps);
     std::stringstream ss;
     for (size_t i = 0; i < timestamps.size(); ++i) {
-      DemuxerStream::Status status;
+      // Initialize status to kAborted since it's possible for Read() to return
+      // without calling StoreStatusAndBuffer() if it doesn't have any buffers
+      // left to return.
+      DemuxerStream::Status status = DemuxerStream::kAborted;
       scoped_refptr<DecoderBuffer> buffer;
       stream->Read(base::Bind(&ChunkDemuxerTest::StoreStatusAndBuffer,
                               base::Unretained(this), &status, &buffer));
@@ -878,6 +881,23 @@ class ChunkDemuxerTest : public ::testing::TestWithParam<bool> {
       if (i > 0)
         ss << " ";
       ss << buffer->timestamp().InMilliseconds();
+
+      // Handle preroll buffers.
+      if (EndsWith(timestamps[i], "P", true)) {
+        scoped_refptr<DecoderBuffer> preroll_buffer;
+        preroll_buffer.swap(buffer);
+
+        // When a preroll buffer is encountered we should be able to request one
+        // more buffer.  The first buffer should have a timestamp equal to the
+        // second buffer and its discard_padding() should be its duration.
+        stream->Read(base::Bind(&ChunkDemuxerTest::StoreStatusAndBuffer,
+                                base::Unretained(this), &status, &buffer));
+        base::MessageLoop::current()->RunUntilIdle();
+        ASSERT_EQ(buffer->timestamp(), preroll_buffer->timestamp());

[acolwell GONE FROM CHROMIUM, 2014/05/23 17:27:30]

nit: remove? The expectations string should be able to capture this. Removing
this also means you don't have too do the special extra Read() above.

[DaleCurtis, 2014/05/23 21:46:26]

Done.

+        ASSERT_EQ(kInfiniteDuration(), preroll_buffer->discard_padding().first);
+        ASSERT_EQ(base::TimeDelta(), preroll_buffer->discard_padding().second);
+        ss << "P";
+      }
     }
     EXPECT_EQ(expected, ss.str());
   }
@@ -3035,8 +3055,8 @@ TEST_P(ChunkDemuxerTest, AppendWindow_Video) {
   ASSERT_TRUE(InitDemuxer(HAS_VIDEO));
   DemuxerStream* stream = demuxer_->GetStream(DemuxerStream::VIDEO);
 
-  // Set the append window to [20,280).
-  append_window_start_for_next_append_ = base::TimeDelta::FromMilliseconds(20);
+  // Set the append window to [50,280).
+  append_window_start_for_next_append_ = base::TimeDelta::FromMilliseconds(50);
   append_window_end_for_next_append_ = base::TimeDelta::FromMilliseconds(280);
 
   // Append a cluster that starts before and ends after the append window.
@@ -3049,7 +3069,7 @@ TEST_P(ChunkDemuxerTest, AppendWindow_Video) {
   CheckExpectedRanges(kSourceId, "{ [120,270) }");
   CheckExpectedBuffers(stream, "120 150 180 210 240");
 
-  // Extend the append window to [20,650).
+  // Extend the append window to [50,650).
   append_window_end_for_next_append_ = base::TimeDelta::FromMilliseconds(650);
 
   // Append more data and verify that adding buffers start at the next
@@ -3063,8 +3083,8 @@ TEST_P(ChunkDemuxerTest, AppendWindow_Audio) {
   ASSERT_TRUE(InitDemuxer(HAS_AUDIO));
   DemuxerStream* stream = demuxer_->GetStream(DemuxerStream::AUDIO);
 
-  // Set the append window to [20,280).
-  append_window_start_for_next_append_ = base::TimeDelta::FromMilliseconds(20);
+  // Set the append window to [50,280).
+  append_window_start_for_next_append_ = base::TimeDelta::FromMilliseconds(50);
   append_window_end_for_next_append_ = base::TimeDelta::FromMilliseconds(280);
 
   // Append a cluster that starts before and ends after the append window.
@@ -3076,19 +3096,19 @@ TEST_P(ChunkDemuxerTest, AppendWindow_Audio) {
   // in the buffer. Also verify that buffers that start inside the
   // window and extend beyond the end of the window are not included.
   //
-  // The first 20ms of the first buffer should be trimmed off since it
+  // The first 50ms of the first buffer should be trimmed off since it

[wolenetz, 2014/05/23 19:59:45]

nit: include mention in comment that the 'first buffer' includes preroll of the
'0K', plus the '30K'?

[DaleCurtis, 2014/05/23 21:46:26]

Done.

   // overlaps the start of the append window.
-  CheckExpectedRanges(kSourceId, "{ [20,270) }");
-  CheckExpectedBuffers(stream, "20 30 60 90 120 150 180 210 240");
+  CheckExpectedRanges(kSourceId, "{ [50,270) }");
+  CheckExpectedBuffers(stream, "50P 60 90 120 150 180 210 240");
 
-  // Extend the append window to [20,650).
+  // Extend the append window to [50,650).
   append_window_end_for_next_append_ = base::TimeDelta::FromMilliseconds(650);
 
   // Append more data and verify that a new range is created.
   AppendSingleStreamCluster(
       kSourceId, kAudioTrackNum,
       "360K 390K 420K 450K 480K 510K 540K 570K 600K 630K");
-  CheckExpectedRanges(kSourceId, "{ [20,270) [360,630) }");
+  CheckExpectedRanges(kSourceId, "{ [50,270) [360,630) }");
 }
 
 TEST_P(ChunkDemuxerTest, AppendWindow_AudioOverlapStartAndEnd) {
@@ -3106,6 +3126,29 @@ TEST_P(ChunkDemuxerTest, AppendWindow_AudioOverlapStartAndEnd) {
   CheckExpectedRanges(kSourceId, "{ }");
 }
 
+TEST_P(ChunkDemuxerTest, AppendWindow_WebMFile_AudioOnly) {
+  EXPECT_CALL(*this, DemuxerOpened());
+  demuxer_->Initialize(
+      &host_,
+      CreateInitDoneCB(base::TimeDelta::FromMilliseconds(2744), PIPELINE_OK),
+      true);
+  ASSERT_EQ(ChunkDemuxer::kOk, AddId(kSourceId, HAS_AUDIO));
+
+  // Set the append window to [50,100).

[acolwell GONE FROM CHROMIUM, 2014/05/23 17:27:30]

nit: s/100/150/ since the comment doesn't match the code?

[DaleCurtis, 2014/05/23 21:46:26]

Done.

+  append_window_start_for_next_append_ = base::TimeDelta::FromMilliseconds(50);
+  append_window_end_for_next_append_ = base::TimeDelta::FromMilliseconds(150);
+
+  // Read a WebM file into memory and send the data to the demuxer.  The chunk
+  // size has been chosen carefully to ensure the preroll buffer used by the
+  // partial append window trim must come from a previous Append() call.
+  scoped_refptr<DecoderBuffer> buffer =
+      ReadTestDataFile("bear-320x240-audio-only.webm");
+  AppendDataInPieces(buffer->data(), buffer->data_size(), 128);
+
+  DemuxerStream* stream = demuxer_->GetStream(DemuxerStream::AUDIO);
+  CheckExpectedBuffers(stream, "50P 62 86 109 122 125 128");
+}
+
 TEST_P(ChunkDemuxerTest, AppendWindow_Text) {
   DemuxerStream* text_stream = NULL;
   EXPECT_CALL(host_, AddTextStream(_, _))