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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