FAB DVB Interface can transmit teletext pages and teletext subtitles as a transport stream (TS) over ASI or IP. To monitor the teletext signal transmitted by FAB DVB Interface it is essential to connect the output of the DVB Multiplexer with all relevant PIDs (PCR, video and teletext received from FAB DVB Interface) back to the input of FAB DVB Interface. FAB DVB Interface requires the PCR to be able to calculate the PTS of the transmitted teletext PID correctly so that it references to the PCR.
To be able to monitor the teletext output the following will be used:
- FAB DVB Interface will receive the teletext PID from the TS input (ASI or IP)
- FAB Subtitler (Demo) can be used to connect to FAB DVB Interface over IP and receive and display teletext pages received by FAB DVB Interface
To check whether the teletext is received back correctly from the DVB Multiplexer by FAB DVB Interface start FAB DVB Monitor and find the teletext PID:
Make sure that the column “Subt PTS - PCR” displays a value between 40 and 120ms. This value can be set in DVB Configuration as “Send before TS”.
To configure FAB Subtitler (Demo) to receive teletext from FAB DVB Interface:
To display a window with a teletext decoder in FAB Subtitler (Demo) click on Display / Teletext decoder: