lib/dvb/pesparse.cpp

   1 #include <lib/base/eerror.h>
   2 #include <lib/dvb/pesparse.h>
   3 #include <memory.h>
   4
   5 ePESParser::ePESParser()
   6 {
   7         m_pes_position = 0;
   8         m_pes_length = 0;
   9         m_header[0] = 0;
  10         m_header[1] = 0;
  11         m_header[2] = 1;
  12         setStreamID(0); /* must be overridden */
  13 }
  14
  15 void ePESParser::setStreamID(unsigned char id, unsigned char id_mask)
  16 {
  17         m_header[3] = id;
  18         m_stream_id_mask = id_mask;
  19 }
  20
  21 void ePESParser::processData(const __u8 *p, int len)
  22 {
  23                 /* this is a state machine, handling arbitary amounts of pes-formatted data. */
  24         while (len)
  25         {
  26                 if (m_pes_position >= 6) // length ok?
  27                 {
  28                         int max = m_pes_length - m_pes_position;
  29                         if (max > len)
  30                                 max = len;
  31                         memcpy(m_pes_buffer + m_pes_position, p, max);
  32                         m_pes_position += max;
  33                         p += max;
  34
  35                         len -= max;
  36
  37                         if (m_pes_position == m_pes_length)
  38                         {
  39                                 processPESPacket(m_pes_buffer, m_pes_position);
  40                                 m_pes_position = 0;
  41                         }
  42                 } else
  43                 {
  44                         if (m_pes_position < 4)
  45                         {
  46                                 unsigned char ch = *p;
  47                                 if (m_pes_position == 3)
  48                                         ch &= m_stream_id_mask;
  49                                 if (ch != m_header[m_pes_position])
  50                                 {
  51 //                                      eDebug("sync lost at %d (%02x)", m_pes_position, *p);
  52                                         m_pes_position = 0;
  53                                         while (m_header[m_pes_position] == ch) /* guaranteed to stop at the old m_pes_position */
  54                                                 m_pes_position++;
  55                                         p++;
  56                                         len--;
  57                                         continue;
  58                                 }
  59                         }
  60                         m_pes_buffer[m_pes_position++] = *p++; len--;
  61                         if (m_pes_position == 6)
  62                         {
  63                                 m_pes_length = ((m_pes_buffer[4] << 8) | m_pes_buffer[5]) + 6;
  64                         }
  65                 }
  66         }
  67 }