media/formats/mp2t/ts_packet.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_TS_PACKET_H_
   6 #define MEDIA_FORMATS_MP2T_TS_PACKET_H_
   7
   8 #include "base/basictypes.h"
   9
  10 namespace media {
  11
  12 class BitReader;
  13
  14 namespace mp2t {
  15
  16 class TsPacket {
  17  public:
  18   static const int kPacketSize = 188;
  19
  20   // Return the number of bytes to discard
  21   // to be synchronized on a TS syncword.
  22   static int Sync(const uint8* buf, int size);
  23
  24   // Parse a TS packet.
  25   // Return a TsPacket only when parsing was successful.
  26   // Return NULL otherwise.
  27   static TsPacket* Parse(const uint8* buf, int size);
  28
  29   ~TsPacket();
  30
  31   // TS header accessors.
  32   bool payload_unit_start_indicator() const {
  33     return payload_unit_start_indicator_;
  34   }
  35   int pid() const { return pid_; }
  36   int continuity_counter() const { return continuity_counter_; }
  37   bool discontinuity_indicator() const { return discontinuity_indicator_; }
  38   bool random_access_indicator() const { return random_access_indicator_; }
  39
  40   // Return the offset and the size of the payload.
  41   const uint8* payload() const { return payload_; }
  42   int payload_size() const { return payload_size_; }
  43
  44  private:
  45   TsPacket();
  46
  47   // Parse an Mpeg2 TS header.
  48   // The buffer size should be at least |kPacketSize|
  49   bool ParseHeader(const uint8* buf);
  50   bool ParseAdaptationField(BitReader* bit_reader,
  51                             int adaptation_field_length);
  52
  53   // Size of the payload.
  54   const uint8* payload_;
  55   int payload_size_;
  56
  57   // TS header.
  58   bool payload_unit_start_indicator_;
  59   int pid_;
  60   int continuity_counter_;
  61
  62   // Params from the adaptation field.
  63   bool discontinuity_indicator_;
  64   bool random_access_indicator_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(TsPacket);
  67 };
  68
  69 }  // namespace mp2t
  70 }  // namespace media
  71
  72 #endif
  73