Intel TV output problems - color pulsing

Justin Hornsby justin at mythtvthemes.co.uk
Fri Dec 14 01:05:31 PST 2007


Robert Lowery wrote:
>> Justin Hornsby wrote:
>>     
>>> Regarding the pulsing effect on the colour of the composite output - at
>>> least as far as the PAL video modes are concerned the driver needs
>>> patched.  I mean to raise a ticket in bugzilla for this but other stuff
>>> keeps getting in the way.
>>>
>>> Anyway in i830_tv.c a value of 286 needs changing to 288 (somewhere in
>>> the "PAL" section).  that solved the problem for me.
>>>       
>
> Looking at the code, I'm not sure this fix is enough.
>
> Later code has
> 1209         if (tv_mode->progressive)
> 1210             ysize = tv_mode->nbr_end + 1;
> 1211         else
> 1212             ysize = 2*tv_mode->nbr_end + 1;
>
> So using
> 286 would result in a ysize = 573
> 288 would result in a ysize = 577
>
> ie neither are right (576).  Hopefully someone with doco can comment.
>
>   
>> Yeah, I saw the posting about this on the list.  I have an NTSC setup,
>> though.  Perhaps a similar bug affects both formats?
>>
>> Richard
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>>     
It was certainly enough to fix the issue on my setup and from everything 
I could measure it was still a perfectly legal PAL video signal.  As 
things are now, it isn't, or some TV PLLs wouldn't have problems locking 
onto the colour burst signal.



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