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_H_ 6 #define MEDIA_FORMATS_MP2T_ES_PARSER_H_ 7 8 #include <list> 9 #include <utility> 10 11 #include "base/basictypes.h" 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 OffsetByteQueue; 21 class StreamParserBuffer; 22 23 namespace mp2t { 24 25 class MEDIA_EXPORT EsParser { 26 public: 27 typedef base::Callback<void(scoped_refptr<StreamParserBuffer>)> EmitBufferCB; 28 29 EsParser(); 30 virtual ~EsParser(); 31 32 // ES parsing. 33 // Should use kNoTimestamp when a timestamp is not valid. 34 bool Parse(const uint8* buf, int size, 35 base::TimeDelta pts, 36 DecodeTimestamp dts); 37 38 // Flush any pending buffer. 39 virtual void Flush() = 0; 40 41 // Reset the state of the ES parser. 42 void Reset(); 43 44 protected: 45 struct TimingDesc { 46 TimingDesc(); 47 TimingDesc(DecodeTimestamp dts, base::TimeDelta pts); 48 49 DecodeTimestamp dts; 50 base::TimeDelta pts; 51 }; 52 53 // Parse ES data from |es_queue_|. 54 // Return true when successful. 55 virtual bool ParseFromEsQueue() = 0; 56 57 // Reset the internal state of the ES parser. 58 virtual void ResetInternal() = 0; 59 60 // Get the timing descriptor with the largest byte count that is less or 61 // equal to |es_byte_count|. 62 // This timing descriptor and all the ones that come before (in stream order) 63 // are removed from list |timing_desc_list_|. 64 // If no timing descriptor is found, then the default TimingDesc is returned. 65 TimingDesc GetTimingDescriptor(int64 es_byte_count); 66 67 // Bytes of the ES stream that have not been emitted yet. 68 scoped_ptr<media::OffsetByteQueue> es_queue_; 69 70 private: 71 // Anchor some timing information into the ES queue. 72 // Here are two examples how this timing info is applied according to 73 // the MPEG-2 TS spec - ISO/IEC 13818: 74 // - "In the case of audio, if a PTS is present in PES packet header it shall 75 // refer to the first access unit commencing in the PES packet. An audio 76 // access unit commences in a PES packet if the first byte of the audio 77 // access unit is present in the PES packet." 78 // - "For AVC video streams conforming to one or more profiles defined 79 // in Annex A of Rec. ITU-T H.264 | ISO/IEC 14496-10 video, if a PTS is 80 // present in the PES packet header, it shall refer to the first AVC access 81 // unit that commences in this PES packet. 82 std::list<std::pair<int64, TimingDesc> > timing_desc_list_; 83 84 DISALLOW_COPY_AND_ASSIGN(EsParser); 85 }; 86 87 } // namespace mp2t 88 } // namespace media 89 90 #endif 91