Add live mode detection in WebM MediaSource parser.

media/filters/ffmpeg_video_decoder.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_video_decoder.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 326 matching lines @@
   ReleaseFFmpegResources();
 
   // Initialize AVCodecContext structure.
   codec_context_.reset(avcodec_alloc_context3(NULL));
   VideoDecoderConfigToAVCodecContext(config_, codec_context_.get());
 
   // Enable motion vector search (potentially slow), strong deblocking filter
   // for damaged macroblocks, and set our error detection sensitivity.
   codec_context_->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
   codec_context_->thread_count = GetThreadCount(codec_context_->codec_id);
+  codec_context_->thread_type =

[scherkus (not reviewing), 2014/04/10 21:11:49]

hmm... did we still want threaded slicing or to disable threading altogether?

[Sergey Ulanov, 2014/04/10 23:10:07]

I think slicing may be useful for live streams to minimize latency introduced by
the decoder.

+      config_.live_mode() ? FF_THREAD_SLICE : FF_THREAD_FRAME;
   codec_context_->opaque = this;
   codec_context_->flags |= CODEC_FLAG_EMU_EDGE;
   codec_context_->get_buffer = GetVideoBufferImpl;
   codec_context_->release_buffer = ReleaseVideoBufferImpl;
 
   AVCodec* codec = avcodec_find_decoder(codec_context_->codec_id);
   if (!codec || avcodec_open2(codec_context_.get(), codec, NULL) < 0) {
     ReleaseFFmpegResources();
     return false;
   }
 
   av_frame_.reset(av_frame_alloc());
   return true;
 }
 
 }  // namespace media