[linuxtv-softmpeg] Chroma artifacting

[Peter Urbanec <linuxtv.org.dvb@urbanec.net>]

Hi again,

I managed to get a Matrox G450 into my system and had another play with 
libsoftmpeg and the demo dfb_ts application. All in all it appears to 
work fairly well. I managed to watch a good chunk of the Malaysian F1 
Grand Prix streamed straight out of /dev/dvb/adapter0/dvr0 on a 
TT-budget DVB-T card.

One thing that I did notice almost straight away is what looks like a 
vertical offset between chrominance and luminance. The chroma appears 1 
or 2 scanlines above the luma. It may also be offset horizontally, but 
if that is the case, it is harder to detect without being able to take a 
snapshot.

I am using the following mode on the primary head of a Matrox G450:

# Progressive PAL
mode "pPAL"
   geometry 720 576 720 576 24
   timings 31208 144 40 32 10 128 3
endmode

There is also a blue (non-solid) line at the bottom of the decoded 
picture. These two symptoms could possibly be related, if there are 
vertical offset issues with the picture being rendered.

It could also be a side effect of deinterlacing - does libsoftmpeg 
attempt to deinterlace? If so, how do I turn this feature off?

It's almost 2am, so I'll give up on the troubleshooting for now, but if 
you have problems reproducing this, please let me know and I'll try to 
provide more information.

Cheers,

   Peter.

--
   "Beauty lies in the hands of the beer holder."




--
Info:  To unsubscribe send a mail to ecartis@linuxtv.org with 
"unsubscribe linuxtv-softmpeg" as subject.