[jitter] Re: Video grabbing quality mystery

Solved!

Thanks for the help.

Here is some info that might help other newbies.

I changed the patch to grab to a jit.window so that I could see the live capture at full DV PAL resolution.

>From the documentation of jit.qt.grab I tried changing various parameters but found that the "singlefield" parameter was key. Setting this to 0 solved the problem. The singlefield parameter tells the digitizer to grab just one field per frame and double it up to full resolution, hence the low quality. Setting it to "0" i.e. off solved the problem.

HOWEVER, the improved quality was not apparent until I changed the "codecquality" attribute. (I was clutching at straws at this point and just going through all the quality settings to see what the difference was). It seemed that it the codecquality setting needs to be refreshed for the singlefield attribute to take effect.

I also found that the "codecquality" attribute applies to "vmode" 1 even though the documentation says it only applies to vmode 2.

Switching interpolation on made no discernible difference but it might help in certain circumstances.


To summarize: use vmode 2 to capture, use codecquality of max or lossless and make sure that the singlefield parametre is set to off (i guess this only applies to interlaced sources?).

Thanks to the forum for the help.

R-)