[Live-devel] Creating a RTSP stream from DVB-T hardware card

[Ryan Walklin]

A couple of other points, here is the structure of a transport packet  
as given by EyeTV:

typedef struct {
	unsigned long			sync_byte : 8,
							transport_error_indicator : 1,
							payload_unit_start_indicator : 1,
							transport_priority : 1,
							PID : 13,
							transport_scrambling_control : 2,
							adaptation_field_control : 2,
							continuity_counter : 4;
					
	unsigned char			data[188-4];
					
} TransportStreamPacket;

And here is the code I'm currently using to access it:

static long PlexTVServerPacketsArrived(PlexTVServerGlobals *globals,  
EyeTVPluginDeviceID deviceID, long **packets, long packetsCount)
{
	long		result = 0;
	int 		i, j, isNewPID;
	TransportStreamPacket *packet;
	
	if (globals)
	{
		DeviceInfo		*deviceInfo = GetDeviceInfo(globals, deviceID);
		if (deviceInfo)
		{
			char packetBuffer[sizeof(TransportStreamPacket)];
			for (i = 0; i < packetsCount; i++)
			{
				packet		= (TransportStreamPacket*)packets[i];
				isNewPID	= 1;
				
				/*
				*	search for PID
				*/
		
				for (j = 0; j < deviceInfo->pidsCount; j++)
				{
					if (packet->PID == deviceInfo->pids[j])
					{
						isNewPID = 0;
						break;
					}
				}
				
				/*
				*	add new PIDs to the DeviceInfo
				*/
				if (isNewPID)
				{
#ifdef TVDBG_VERBOSE
					printf ("PlexTVServer: SamplePacketsArrived, newPID = %6li\n",  
packet->PID);
#endif
					if (deviceInfo->pidsCount < MAX_PIDS)
					{
						deviceInfo->pids[deviceInfo->pidsCount++] = packet->PID;
					}
				}
				//stream packets to RTSP server
				memcpy(packetBuffer, packet, sizeof(TransportStreamPacket));
				write(streamfd[STREAM_INPUT], packetBuffer,  
sizeof(TransportStreamPacket));
			}
			//void *packetBuffer = malloc(packetsCount *  
sizeof(TransportStreamPacket));
			//memcpy(packetBuffer, packets, sizeof(TransportStreamPacket) *  
packetsCount);
			//write(streamfd[STREAM_INPUT], packetBuffer,  
sizeof(TransportStreamPacket) * packetsCount);
			//free(packetBuffer);
			globals->packetCount+=packetsCount;
#ifdef TVDBG_VERBOSE
			printf("Packetcount: %lli\n", globals->packetCount);
#endif
		}
	}
	
	return result;
}

According to the EyeTV documentation, the **packets array is the  
actual data coming from the card, rather than a copy, so it seems to  
be quite sensitive to interference, hence copying the packets before  
piping them to the server.