[mythtv] Re: [experimental patch] vbi decoder for IVTV cards

Martin Barnasconi mythtv at barnasconi.net
Fri Apr 8 23:11:36 UTC 2005

On Friday 08 April 2005 18:37, Johan Duinkerken wrote:
> OK, some progress... :-)
> I can watch teletext in color on my computer-monitor with a nice, stable
> picture. Furthermore, I've got my ivtv-framebuffer working, so MythTV shows
> on my TV as well. But. On TV the movie shows ok, the OSD shows ok (even in
> color!), but teletext does not show.
> I'm quite sure that something is activated, because after pressing the
> "T"-button, which normally activates teletext, I notice that my "up" and
> "down" keys (to switch channels) don't respond anymore. As soon as I press
> "T" again, to switch (the invisble) teletext off, my "up" and "down" keys
> work again.
> Shouldn't teletext be visible if OSD does show on my TV-set?

The teletext overlay has its own OSD: OSDtypeteletext, derived from the main 
OSD class. I only tested this for Xv video output, as I have a PVR250 card. 
Your TV output goes via the ivtv videooutput driver; guess you need to add 
some things here...
Alternative approach is to do a vbi passthrough to the TV output, and you 
should be able to view the teletext by using your "normal" teletext button on 
the remote of your TV.
vbi passthrough can be enabled by using the ivtvctl program as part of the 
ivtv sources. I have no idea if this works in myth, since myth will set the 
ivtv card in vbi embedded mode.
Please let me know if this works or not; we can add an option to the menu 
later to define whether vbi needs to be embedded or if passthrough is 

> Best regards,
> Johan Duinkerken.


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