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         int i;
  24
  25                 /* this is a state machine, handling arbitary amounts of pes-formatted data. */
  26         while (len)
  27         {
  28                 if (m_pes_position >= 6) // length ok?
  29                 {
  30                         int max = m_pes_length - m_pes_position;
  31                         if (max > len)
  32                                 max = len;
  33                         memcpy(m_pes_buffer + m_pes_position, p, max);
  34                         m_pes_position += max;
  35                         p += max;
  36
  37                         len -= max;
  38
  39                         if (m_pes_position == m_pes_length)
  40                         {
  41                                 processPESPacket(m_pes_buffer, m_pes_position);
  42                                 m_pes_position = 0;
  43                         }
  44                 } else
  45                 {
  46                         if (m_pes_position < 4)
  47                         {
  48                                 unsigned char ch = *p;
  49                                 if (m_pes_position == 3)
  50                                         ch &= m_stream_id_mask;
  51                                 if (ch != m_header[m_pes_position])
  52                                 {
  53 //                                      eDebug("sync lost at %d (%02x)", m_pes_position, *p);
  54                                         m_pes_position = 0;
  55                                         while (m_header[m_pes_position] == ch) /* guaranteed to stop at the old m_pes_position */
  56                                                 m_pes_position++;
  57                                         p++;
  58                                         len--;
  59                                         continue;
  60                                 }
  61                         }
  62                         m_pes_buffer[m_pes_position++] = *p++; len--;
  63                         if (m_pes_position == 6)
  64                         {
  65                                 m_pes_length = ((m_pes_buffer[4] << 8) | m_pes_buffer[5]) + 6;
  66                         }
  67                 }
  68         }
  69 }