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R5D1 - Capture card - NTSC OK but PAL picture scrambled
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Author:  Gerryo [ Sat Jan 13, 2007 5:40 pm ]
Post subject:  R5D1 - Capture card - NTSC OK but PAL picture scrambled
New install of R5D1 (tried R5E50 but got lockups).

TV card is an old generic bt848 card, manufacturer unknown, no tv tuner.

bttv0: using: *** UNKNOWN/GENERIC *** [card=0,autodetected]
bttv0: using tuner=-1

First question, is 'tuner=-1' the same as 'tuner=4', can't find '-1' listed on the CARDSLIST or on the 'BTTV HOWTO'?

Using the 'Composite 1' input.

Got the card working with NTSC, I had an old NTSC video camera handy. Everything worked as expected.

Hooked the card up to a VCR, changed the Mythtv TV standard to PAL.
When watching tv the picture is scrambled, like encrypted TV signals, just bits of colour all over the screen. Or maybe like when vsync is lost.

Second question, I'm pretty sure the bt848 chip supports PAL, I must have missed a setting somewhere, but where?

I know PAL has to be set in Mythtv-setup->General screen, I've been thru the screens a few times, can't see where else.

If I set it back to NTSC & feed the VCR signal into the card, the picture is viewable, but mostly green & a bit truncated, with noise bars on the top.

Searched the forums & google, can't find anyone with a prob like this.

Third question, do I need to re-install Mythtv for a TV format change like this?

Regards
Gerry
Author:  bruce_s01 [ Sat Jan 13, 2007 8:51 pm ]
Post subject: 
As well as the PAL setting in mythtv-setup->General, did you set the correct area and VBI setting on the same screen?
In Video Sources, there is requirement for a channel frequency table, I don't think this affects you, not having a tuner, but it might be better setting this as well.
In the Channel Editor there is an entry for each particular channel TV Format, it might be worthwhile setting this to PAL to make sure.

Quote:
do I need to re-install Mythtv for a TV format change like this?
There shouldn't be a requirement to do this, as mythtv-setup should set the correct type.

Bruce S.
Author:  Gerryo [ Sun Jan 14, 2007 9:46 am ]
Post subject: 
Mystery solved!

My capture card is old, it uses the bt848 chip, not the bt848a.

The old bt848 chip needed a different crystal for PAL, the board I have is equiped with a crystal for NTSC only. Guess I'll have to change it if I want to use it for PAL.

Newer bt848a chips can do PAL/NTSC using one crystal.

Found this out by reading the bttv howto pages, as well as the Brooktree chip specifications.

Thanks for the reply Bruce, turns out to be a hardware problem afterall.


Gerry
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