void process_current_packet (cc708_service_decoder *decoders)
{
int seq = (decoders[0].parent->m_current_packet[0] & 0xC0) >> 6; // Two most significants bits
int len = decoders[0].parent->m_current_packet[0] & 0x3F; // 6 least significants bits
if (decoders[0].parent->m_current_packet_length == 0)
return;
if (len==0) // This is well defined in EIA-708; no magic.
len=128;
else
len=len*2;
// Note that len here is the length including the header
if (decoders[0].parent->m_current_packet_length != len) // Is this possible?
{
cc708_reset(decoders);
return;
}
int last_seq = decoders[0].parent->m_last_seq;
if ((last_seq != -1) && ((last_seq+1)%4 != seq))
{
cc708_reset(decoders);
return;
}
decoders[0].parent->m_last_seq = seq;
unsigned char *pos = decoders[0].parent->m_current_packet + 1;
while (pos < decoders[0].parent->m_current_packet + len)
{
int service_number=(pos[0] & 0xE0)>>5; // 3 more significant bits
int block_length = (pos[0] & 0x1F); // 5 less significant bits
if (service_number==7) // There is an extended header
{
pos++;
service_number=(pos[0] & 0x3F); // 6 more significant bits
if (service_number<7)
{
}
pos = decoders[0].parent->m_current_packet + len;
break;
}
pos++; // Move to service data
if (service_number==0 && block_length!=0) // Illegal, but specs say what to do...
{
pos = decoders[0].parent->m_current_packet + len; // Move to end
break;
}
if (service_number>0 && decoders[service_number].inited)
process_service_block (&decoders[service_number], pos, block_length);
pos+=block_length; // Skip data
}
clear_packet(&decoders[0]);
if (pos != decoders[0].parent->m_current_packet + len) // For some reason we didn't parse the whole packet
{
cc708_reset(decoders);
}
if (len<128 && *pos) // Null header is mandatory if there is room
{
;//ccx_common_logging.debug_ftn(CCX_DMT_708, "Warning: Null header expected but not found.\n");
}
}
void process_current_packet (void)
{
#ifdef DEBUG_708_PACKETS
printf ("Processing EIA-708 packet, length=%d\n",current_packet_length);
#endif
if (current_packet_length==0)
return;
int seq=(current_packet[0] & 0xC0) >> 6; // Two most significants bits
int len=current_packet[0] & 0x3F; // 6 least significants bits
if (len==0) // This is well defined in EIA-708; no magic.
len=128;
else
len=len*2;
// Note that len here is the length including the header
#ifdef DEBUG_708_PACKETS
printf ("Sequence: %d, packet length: %d\n",seq,len);
#endif
if (current_packet_length!=len) // Is this possible?
{
printf ("Packet length mismatch (%s%d), first two data bytes %02X %02X, current picture:%s\n",
current_packet_length-len>0?"+":"", current_packet_length-len,
current_packet[0], current_packet[1], pict_types[current_picture_coding_type]);
cc708_reset();
return;
}
if (last_seq!=-1 && (last_seq+1)%4!=seq)
{
printf ("Unexpected sequence number, it was [%d] but should have been [%d]\n",
seq,(last_seq+1)%4);
cc708_reset();
return;
}
last_seq=seq;
unsigned char *pos=current_packet+1;
while (pos<current_packet+len)
{
int service_number=(pos[0] & 0xE0)>>5; // 3 more significant bits
int block_length = (pos[0] & 0x1F); // 5 less significant bits
#ifdef DEBUG_708_PACKETS
printf ("Standard header: Service number: [%d] Block length: [%d]\n",service_number,
block_length);
#endif
if (service_number==7) // There is an extended header
{
pos++;
service_number=(pos[0] & 0x3F); // 6 more significant bits
// printf ("Extended header: Service number: [%d]\n",service_number);
if (service_number<7)
{
printf ("Illegal service number in extended header: [%d]\n",service_number);
}
}
/*
if (service_number==0 && block_length==0) // Null header already?
{
if (pos!=(current_packet+len-1)) // i.e. last byte in packet
{
// Not sure if this is correct
printf ("Null header before it was expected.\n");
// break;
}
} */
pos++; // Move to service data
if (service_number==1) // Primary language
process_service_block (&decoders[0], pos, block_length);
if (service_number==2) // Secondary language
process_service_block (&decoders[1], pos, block_length);
pos+=block_length; // Skip data
}
clear_packet();
if (pos!=current_packet+len) // For some reason we didn't parse the whole packet
{
printf ("There was a problem with this packet, reseting\n");
cc708_reset();
}
if (len<128 && *pos) // Null header is mandatory if there is room
{
printf ("Warning: Null header expected but not found.\n");
}
}
