media/formats/mp2t/es_adapter_video.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_FORMATS_MP2T_ES_ADAPTER_VIDEO_H_
   6 #define MEDIA_FORMATS_MP2T_ES_ADAPTER_VIDEO_H_
   7
   8 #include <deque>
   9 #include <list>
  10 #include <utility>
  11
  12 #include "base/callback.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/time/time.h"
  15 #include "media/base/media_export.h"
  16 #include "media/base/stream_parser_buffer.h"
  17
  18 namespace media {
  19
  20 class VideoDecoderConfig;
  21
  22 namespace mp2t {
  23
  24 // Some constraints of the MSE spec are not necessarily met by video streams
  25 // inside an Mpeg2 TS stream.
  26 // The goal of the ES adapter is to modify the incoming buffers to meet these
  27 // constraints, e.g.
  28 // - get the frame duration,
  29 // - replace the leading non-key frames by the first key frame to avoid
  30 //   creating a hole in the video timeline.
  31 class MEDIA_EXPORT EsAdapterVideo {
  32  public:
  33   typedef base::Callback<void(const VideoDecoderConfig&)> NewVideoConfigCB;
  34   typedef base::Callback<void(scoped_refptr<StreamParserBuffer>)> EmitBufferCB;
  35
  36   EsAdapterVideo(
  37       const NewVideoConfigCB& new_video_config_cb,
  38       const EmitBufferCB& emit_buffer_cb);
  39   ~EsAdapterVideo();
  40
  41   // Force the emission of the pending video buffers.
  42   void Flush();
  43
  44   // Reset the ES adapter to its initial state.
  45   void Reset();
  46
  47   // Provide the configuration that applies to the upcoming video buffers.
  48   void OnConfigChanged(const VideoDecoderConfig& video_decoder_config);
  49
  50   // Provide a new video buffer.
  51   // Returns true when successful.
  52   bool OnNewBuffer(
  53       const scoped_refptr<StreamParserBuffer>& stream_parser_buffer);
  54
  55  private:
  56   typedef std::deque<scoped_refptr<StreamParserBuffer> > BufferQueue;
  57   typedef std::pair<int64, VideoDecoderConfig> ConfigEntry;
  58
  59   void ProcessPendingBuffers(bool flush);
  60
  61   // Return the PTS of the frame that comes just after |current_pts| in
  62   // presentation order. Return kNoTimestamp() if not found.
  63   base::TimeDelta GetNextFramePts(base::TimeDelta current_pts);
  64
  65   // Replace the leading non key frames by |stream_parser_buffer|
  66   // (this one must be a key frame).
  67   void ReplaceDiscardedFrames(
  68       const scoped_refptr<StreamParserBuffer>& stream_parser_buffer);
  69
  70   NewVideoConfigCB new_video_config_cb_;
  71   EmitBufferCB emit_buffer_cb_;
  72
  73   bool has_valid_config_;
  74   bool has_valid_frame_;
  75
  76   // Duration of the last video frame.
  77   base::TimeDelta last_frame_duration_;
  78
  79   // Association between a video config and a buffer index.
  80   std::list<ConfigEntry> config_list_;
  81
  82   // Global index of the first buffer in |buffer_list_|.
  83   int64 buffer_index_;
  84
  85   // List of buffer to be emitted and PTS of frames already emitted.
  86   BufferQueue buffer_list_;
  87   std::list<base::TimeDelta> emitted_pts_;
  88
  89   // Minimum PTS/DTS since the last Reset.
  90   bool has_valid_initial_timestamp_;
  91   base::TimeDelta min_pts_;
  92   DecodeTimestamp min_dts_;
  93
  94   // Number of frames to replace with the first valid key frame.
  95   int discarded_frame_count_;
  96
  97   DISALLOW_COPY_AND_ASSIGN(EsAdapterVideo);
  98 };
  99
 100 }  // namespace mp2t
 101 }  // namespace media
 102
 103 #endif  // MEDIA_FORMATS_MP2T_ES_ADAPTER_VIDEO_H_