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

[Simon Kagstrom]

Thanks for the answer!

At Tue, 04 Apr 2006 16:00:39 +0100,
Ivor Hewitt wrote:
>  > 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.

(corrected in the other mail). 700x520 was a guess on my part, but it
seems like a reasonable explanation.

> 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.

I'll get a TV test image, although I'm not really sure what the "TV
safe" and "text safe" boundaries are. Are the text safe area the
black/white bars around the edges?

http://en.wikipedia.org/wiki/Image:Pm5544.png

>  > 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.

If someone can point me in the correct direction, I can do some tests
at least. Is that the VT1623Modes in via_vt162x.h? (or is that just
the standard modelines?) If I risk frying the TV I'm a bit reluctant
though :-)

// Simon