Monday, 21 June 2010

Teletext part 1

Well, the teletext descriptor has been added to
the PMT (that is the table that defines the PIDs
for the video, audio and PCR elementary streams
for a program). Now when I press the teletext button
on the remote it goes into teletext mode and waits.
Before it just said "service not available".

Next I have to figure out the format of the Teletext
PES packets so I can load some pages.

OpenCaster has an application that generate a PES
packet from a text file. That would be an easy way
to add the pages but when I tried it I could not
get it to work. More research needed.


  1. hi, i'm one of the people involved in OpenCaster. i just stumbled on your blog and i see you're doing great with the DVB-T soft-modulation.. i'm happy to find that OpenCaster could help you here.

    WRT Teletext, i believe you have to:

    - prepare python description of EBUTeletextUnit (look at the manual or python libraries source code),

    - then marshal those data structures into elementary streams (TXT is put into ES and not sections in DVB)

    - then use txt2pes with standard params to bring ES to PES and,

    - finally "pesdata2ts" to get from PES to TS,

    then you're done. :-)

    hope it helps



  2. Hello Andrea,

    My problem was I tried doing it without reading the manual! I will need to add some code to my GUI to allow the loading of a Teletext file.

    The program requires program streams rather than transport streams, it converts them into transport streams internally.

    OpenCaster was very helpful while I was debugging the SI table generation in my code.

    In fact without it I probably would not have even tried doing DVB.

    - Charles

    1. do u have idea of mpeg 2 re-multiplexer using opencaster

    2. No I have no plans to do that.