Conditional filtering based on framenumber range

[Dosdan]

I'm using VDubMod and Avisynth 2.5.5.

I'm doing a VHS to DVD conversion of DV footage of South Pacific Islanders. The person who took the original video tried to compensate,in a number of shots, for the difficultly of seeing facial details on their dark faces by using the Backlight button on the camera. As a result the backgrounds are way overexposed in some segements.

What I'm after is:

1. An AviSynth YUV2 midpoint and blacklevel adjustment filter like Vdub's Levels. Something that had 2 midpoints (say Upper/Lower) would be even better. If there is nothing available, then something to do a Gamma adjustment would be better than nothing.

2. An elegant technique to conditionally apply this filter only to the nominated framenumber ranges within the full clip.

Thanks.

[feenix]

I can't help you mutch with the filter as I don't really understand what you want but the following script is an example of how to apply filters to a section of a file and not the whole thing. In this case I am applying Deinterlace and Sharpen filters to the first 30 seconds (750 frames) of an avi file and no filtering to the rest of the file:-


vid=AVISource("D:\Capture 1\capture.00.avi")
a=Trim(MSharpen(kerneldeint(vid,0),strength=25),0, 750)
b=Trim(vid,751,0)
video=a+b
return video

Hope this helps and you find the actual filter you need

[Dosdan]

Thanks for that. I try it as soon as I can get the time. My "video=" expression is going to have lots of variables in it as I specify alternating trimmed to-be-filtered and don't-touch ranges.

I think I'll be using the YLevels filter to adjust the gamma curve.