ffmpeg reset bitstream converters on Seek

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/base64.h"
@@ skipping 367 matching lines @@
   end_of_stream_ = true;
   SatisfyPendingRead();
 }
 
 void FFmpegDemuxerStream::FlushBuffers() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(read_cb_.is_null()) << "There should be no pending read";
   buffer_queue_.Clear();
   end_of_stream_ = false;
   last_packet_timestamp_ = kNoTimestamp();
   last_packet_duration_ = kNoTimestamp();

[xhwang, 2014/10/30 03:36:20]

ditto, call ResetBitstreamConverter() here?

 }
 
 void FFmpegDemuxerStream::Stop() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   buffer_queue_.Clear();
   if (!read_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(
         DemuxerStream::kOk, DecoderBuffer::CreateEOSBuffer());
   }
   demuxer_ = NULL;
@@ skipping 28 matching lines @@
   DCHECK(task_runner_->BelongsToCurrentThread());
 
 #if defined(USE_PROPRIETARY_CODECS)
   CHECK(bitstream_converter_.get());
   bitstream_converter_enabled_ = true;
 #else
   NOTREACHED() << "Proprietary codecs not enabled.";
 #endif
 }
 
+void FFmpegDemuxerStream::ResetBitstreamConverter() {
+  // If a bitstream converter exists, reset it.

[xhwang, 2014/10/30 03:36:20]

This comment doesn't belong here.

[kjoswiak, 2014/10/30 17:43:06]

Done.

+  if (!bitstream_converter_enabled_)

[xhwang, 2014/10/30 03:36:20]

bitstream_converter_enabled_ is inited in ctor, then it's always in #if
defined(USE_PROPRIETARY_CODECS). Can we also put it after l.442? Then you can
combine this check with the check on l.443.

[kjoswiak, 2014/10/30 17:43:06]

Done.

+    return;
+
+#if defined(USE_PROPRIETARY_CODECS)
+  if (!bitstream_converter_)
+    return;
+
+  bitstream_converter_.reset(
+      new FFmpegH264ToAnnexBBitstreamConverter(stream_->codec));

[kjoswiak, 2014/10/29 20:24:27]

Hmm, given https://code.google.com/p/chromium/issues/detail?id=144432 /
https://chromiumcodereview.appspot.com/10879057 worried this could cause same
issue

+#endif  // defined(USE_PROPRIETARY_CODECS)
+}
+
 bool FFmpegDemuxerStream::SupportsConfigChanges() { return false; }
 
 AudioDecoderConfig FFmpegDemuxerStream::audio_decoder_config() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   CHECK_EQ(type_, AUDIO);
   return audio_config_;
 }
 
 VideoDecoderConfig FFmpegDemuxerStream::video_decoder_config() {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ skipping 139 matching lines @@
 }
 
 void FFmpegDemuxer::Seek(base::TimeDelta time, const PipelineStatusCB& cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   CHECK(!pending_seek_);
 
   // TODO(scherkus): Inspect |pending_read_| and cancel IO via |blocking_url_|,
   // otherwise we can end up waiting for a pre-seek read to complete even though
   // we know we're going to drop it on the floor.
 
+  FFmpegDemuxerStream* video = GetFFmpegStream(DemuxerStream::VIDEO);
+  // H264 requires that we resend the header after flush.
+  // Reset its bitstream for converter to do so.
+  // This is related to chromium issue 140371 (http://crbug.com/140371).
+  if (video)
+    video->ResetBitstreamConverter();

[xhwang, 2014/10/30 03:36:20]

Instead of doing this, can we handle ResetbitstreamConverter() in
FFmpegDemuxerStream::FlushBuffers()? FlushBuffers() will always be called after
the seek is done. See l.1089.

[kjoswiak, 2014/10/30 17:44:32]

Done.

+
   // FFmpeg requires seeks to be adjusted according to the lowest starting time.
   // Since EnqueuePacket() rebased negative timestamps by the start time, we
   // must correct the shift here.
   //
   // Additionally, to workaround limitations in how we expose seekable ranges to
   // Blink (http://crbug.com/137275), we also want to clamp seeks before the
   // start time to the start time.
   const base::TimeDelta seek_time =
       start_time_ < base::TimeDelta() ? time + start_time_
                                       : time < start_time_ ? start_time_ : time;
@@ skipping 642 matching lines @@
   }
   for (size_t i = 0; i < buffered.size(); ++i)
     host_->AddBufferedTimeRange(buffered.start(i), buffered.end(i));
 }
 
 void FFmpegDemuxer::OnDataSourceError() {
   host_->OnDemuxerError(PIPELINE_ERROR_READ);
 }
 
 }  // namespace media