[MPlayer-users] Blotchy Colors (revisited)

[D Richard Felker III]

On Tue, Apr 01, 2003 at 12:22:37PM -0500, spowers at inland.k12.mi.us wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> As with most things regarding *nix, I've learned a lot in trying to fix my
> problems. :)
> 
> I am sorry to bug the list again, but I'm struggling to find "where to
> look" to RTFM. :)
> 
> My problem is that colors are blotchy in most of my video when seen on a
> television.  I use a scan converter to convert the VGA signal into svideo,
> and input that into video in on my TV.  I don't notice the blotchy colors
> on a regular monitor, so I assume somewhere in the scan conversion (the
> little piece of hardware) the colors are messed up.  When on the TV, it
> appears almost like it's 8bpp rather than the 24bpp that is really is.
> 
> I freely admit I dont' understand what yuv12, yuy2, rbg2gbr, etc, etc, etc
> all mean.  Can someone point me to information, so that I can
> intelligently try different filters?  Does it make sense that the scan
> converter would choke?  Have I missed a general rule required to make
> TV-Out work right?  I know the TV can handle the colors, because our DVD
> player obviously doesn't have these issues, but both DVDs and divx files
> played through the computer have the color problem.

Scan converters generally suck. You might have better results if you
set the video mode to exact NTSC (or PAL if you're using a PAL TV)
spec, but it would be much better if you could do this and then bypass
the scan converter altogether, just using a simple piece of hardware
to convert the colorspace and generate the right luma and chroma
signals.

Basically, scan converters have to digitize the whole frame, then
scale it with their crappy scaling algorithms, then output the picture
at TV refresh rate/spec. Naturally this looks horrible...

Of course there's also the possibility that something else is wrong in
your setup. Perhaps your scan converter is designed to try to make
computer displays with text and stuff on them more readable by
adjusting the colors, and so it's doing a horrible job with full
natural color movies...

Rich