Add VideoCodec::PreferDecodeLate

webrtc/video_decoder.h

 /*
  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 45 matching lines @@
                          bool missing_frames,
                          const RTPFragmentationHeader* fragmentation,
                          const CodecSpecificInfo* codec_specific_info = NULL,
                          int64_t render_time_ms = -1) = 0;
 
   virtual int32_t RegisterDecodeCompleteCallback(
       DecodedImageCallback* callback) = 0;
 
   virtual int32_t Release() = 0;
   virtual int32_t Reset() = 0;
+
+  // Returns true if the currently active decoder only have one output buffer.

[perkj_webrtc, 2015/11/05 11:56:37]

has

+  // That means that frames must be decoded near the render times stamp since
+  // multiple frames can not be decoded ahead of time.
+  virtual bool HasOnlyOneOutputBuffer() const {

[pbos-webrtc, 2015/11/05 17:47:30]

I would like us to decode the extra output buffer as soon as it's available, was
that impossible to wire up?

+    return false;
+  }
 };
 
 // Class used to wrap external VideoDecoders to provide a fallback option on
 // software decoding when a hardware decoder fails to decode a stream due to
 // hardware restrictions, such as max resolution.
 class VideoDecoderSoftwareFallbackWrapper : public webrtc::VideoDecoder {
  public:
   VideoDecoderSoftwareFallbackWrapper(VideoCodecType codec_type,
                                       VideoDecoder* decoder);
 
   int32_t InitDecode(const VideoCodec* codec_settings,
                      int32_t number_of_cores) override;
 
   int32_t Decode(const EncodedImage& input_image,
                  bool missing_frames,
                  const RTPFragmentationHeader* fragmentation,
                  const CodecSpecificInfo* codec_specific_info,
                  int64_t render_time_ms) override;
 
   int32_t RegisterDecodeCompleteCallback(
       DecodedImageCallback* callback) override;
 
   int32_t Release() override;
   int32_t Reset() override;
+  bool HasOnlyOneOutputBuffer() const override;
 
  private:
   bool InitFallbackDecoder();
 
   const DecoderType decoder_type_;
   VideoDecoder* const decoder_;
 
   VideoCodec codec_settings_;
   int32_t number_of_cores_;
   rtc::scoped_ptr<VideoDecoder> fallback_decoder_;
   DecodedImageCallback* callback_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_DECODER_H_