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 <stdint.h> 9 10 #include <list> 11 #include <memory> 12 #include <utility> 13 14 #include "base/callback.h" 15 #include "base/macros.h" 16 #include "base/memory/ref_counted.h" 17 #include "base/time/time.h" 18 #include "media/base/media_export.h" 19 #include "media/base/stream_parser_buffer.h" 20 21 namespace media { 22 23 class DecryptConfig; 24 class OffsetByteQueue; 25 class StreamParserBuffer; 26 27 namespace mp2t { 28 29 class MEDIA_EXPORT EsParser { 30 public: 31 using EmitBufferCB = 32 base::RepeatingCallback<void(scoped_refptr<StreamParserBuffer>)>; 33 using GetDecryptConfigCB = base::RepeatingCallback<const DecryptConfig*()>; 34 35 EsParser(); 36 virtual ~EsParser(); 37 38 // ES parsing. 39 // Should use kNoTimestamp when a timestamp is not valid. 40 bool Parse(const uint8_t* buf, 41 int size, 42 base::TimeDelta pts, 43 DecodeTimestamp dts); 44 45 // Flush any pending buffer. 46 virtual void Flush() = 0; 47 48 // Reset the state of the ES parser. 49 void Reset(); 50 51 protected: 52 struct TimingDesc { 53 TimingDesc(); 54 TimingDesc(DecodeTimestamp dts, base::TimeDelta pts); 55 56 DecodeTimestamp dts; 57 base::TimeDelta pts; 58 }; 59 60 // Parse ES data from |es_queue_|. 61 // Return true when successful. 62 virtual bool ParseFromEsQueue() = 0; 63 64 // Reset the internal state of the ES parser. 65 virtual void ResetInternal() = 0; 66 67 // Get the timing descriptor with the largest byte count that is less or 68 // equal to |es_byte_count|. 69 // This timing descriptor and all the ones that come before (in stream order) 70 // are removed from list |timing_desc_list_|. 71 // If no timing descriptor is found, then the default TimingDesc is returned. 72 TimingDesc GetTimingDescriptor(int64_t es_byte_count); 73 74 // Bytes of the ES stream that have not been emitted yet. 75 std::unique_ptr<media::OffsetByteQueue> es_queue_; 76 77 private: 78 // Anchor some timing information into the ES queue. 79 // Here are two examples how this timing info is applied according to 80 // the MPEG-2 TS spec - ISO/IEC 13818: 81 // - "In the case of audio, if a PTS is present in PES packet header it shall 82 // refer to the first access unit commencing in the PES packet. An audio 83 // access unit commences in a PES packet if the first byte of the audio 84 // access unit is present in the PES packet." 85 // - "For AVC video streams conforming to one or more profiles defined 86 // in Annex A of Rec. ITU-T H.264 | ISO/IEC 14496-10 video, if a PTS is 87 // present in the PES packet header, it shall refer to the first AVC access 88 // unit that commences in this PES packet. 89 std::list<std::pair<int64_t, TimingDesc>> timing_desc_list_; 90 91 DISALLOW_COPY_AND_ASSIGN(EsParser); 92 }; 93 94 } // namespace mp2t 95 } // namespace media 96 97 #endif // MEDIA_FORMATS_MP2T_ES_PARSER_H_ 98