[Openchrome-users] TV-out grayscale and cropped on sp13000/openchrome/720x576Noscale

[Ivor Hewitt]

Simon Kagstrom wrote:
 >
 > I have some problems getting tv-out to work well with my Via
 > sp13000. I use a s-video connection to my TV (which is a 5-year old
 > fairly good widescreen TV).
 >
 > My problem is that the 720x576Noscale mode gives a slightly cropped
 > image, only something like 700x520 pixels actually fit on the screen
 > (most is shown with the TV in 4x3 mode). Also, the image is often
 > gray-scale, although this can be fixed by switching back and forth
 > between 720x576Noscale and other modes.
 >
Well you should be getting some overscan, it should be about 5-10% of 
the image so 76 pixels does seem a bit much.
It's probably worth getting a TV test card image to display that shows 
the tv safe and text safe boundaries (I used to have one but can't find 
it) and take a look to see just what sort of overscan youre getting.

The grey image is probably caused by the picture being too far 
overscanned and the TV is missing the chroma.

 > I've tried both the latest svn-openchrome (without libXvMc, which I
 > haven't been able to compile yet) and the stock Debian/Testing X.org
 > 6.9 driver and it looks the same with both options.
 >
There's been no change in that TV code so they will all show the same 
output.

It needs someone with the datasheet to spend some time tweaking / 
adjusting the values. Terry Barnaby was the man, but he's been quiet lately.

 > Could this be a widescreen TV issue?
 >
No. not when you're using svideo, it's still just normal PAL signal 
you're putting out.

-- 
Ivor
http://www.ivor.it