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      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_PARSER_H264_H_
      6 #define MEDIA_FORMATS_MP2T_ES_PARSER_H264_H_
      7 
      8 #include <list>
      9 #include <utility>
     10 
     11 #include "base/basictypes.h"
     12 #include "base/callback.h"
     13 #include "base/compiler_specific.h"
     14 #include "base/memory/scoped_ptr.h"
     15 #include "base/time/time.h"
     16 #include "media/base/media_export.h"
     17 #include "media/base/video_decoder_config.h"
     18 #include "media/formats/mp2t/es_adapter_video.h"
     19 #include "media/formats/mp2t/es_parser.h"
     20 
     21 namespace media {
     22 class H264Parser;
     23 struct H264SPS;
     24 class OffsetByteQueue;
     25 }
     26 
     27 namespace media {
     28 namespace mp2t {
     29 
     30 // A few remarks:
     31 // - In this h264 parser, frame splitting is based on AUD nals.
     32 // Mpeg2 TS spec: "2.14 Carriage of Rec. ITU-T H.264 | ISO/IEC 14496-10 video"
     33 // "Each AVC access unit shall contain an access unit delimiter NAL Unit;"
     34 // - PES packets do not necessarily map to an H264 access unit although the HLS
     35 // recommendation is to use one PES for each access unit. In this parser,
     36 // we handle the general case and do not make any assumption about the access
     37 // unit organization within PES packets.
     38 //
     39 class MEDIA_EXPORT EsParserH264 : public EsParser {
     40  public:
     41   typedef base::Callback<void(const VideoDecoderConfig&)> NewVideoConfigCB;
     42 
     43   EsParserH264(const NewVideoConfigCB& new_video_config_cb,
     44                const EmitBufferCB& emit_buffer_cb);
     45   virtual ~EsParserH264();
     46 
     47   // EsParser implementation.
     48   virtual void Flush() OVERRIDE;
     49 
     50  private:
     51   // EsParser implementation.
     52   virtual bool ParseFromEsQueue() OVERRIDE;
     53   virtual void ResetInternal() OVERRIDE;
     54 
     55   // Find the AUD located at or after |*stream_pos|.
     56   // Return true if an AUD is found.
     57   // If found, |*stream_pos| corresponds to the position of the AUD start code
     58   // in the stream. Otherwise, |*stream_pos| corresponds to the last position
     59   // of the start code parser.
     60   bool FindAUD(int64* stream_pos);
     61 
     62   // Emit a frame whose position in the ES queue starts at |access_unit_pos|.
     63   // Returns true if successful, false if no PTS is available for the frame.
     64   bool EmitFrame(int64 access_unit_pos, int access_unit_size,
     65                  bool is_key_frame, int pps_id);
     66 
     67   // Update the video decoder config based on an H264 SPS.
     68   // Return true if successful.
     69   bool UpdateVideoDecoderConfig(const H264SPS* sps);
     70 
     71   EsAdapterVideo es_adapter_;
     72 
     73   // H264 parser state.
     74   // - |current_access_unit_pos_| is pointing to an annexB syncword
     75   // representing the first NALU of an H264 access unit.
     76   scoped_ptr<H264Parser> h264_parser_;
     77   int64 current_access_unit_pos_;
     78   int64 next_access_unit_pos_;
     79 
     80   // Last video decoder config.
     81   VideoDecoderConfig last_video_decoder_config_;
     82 
     83   DISALLOW_COPY_AND_ASSIGN(EsParserH264);
     84 };
     85 
     86 }  // namespace mp2t
     87 }  // namespace media
     88 
     89 #endif
     90