Resizing or cropping causes scrambled video

[steptoe]

Can somebody please suggest whats going wrong with a video I'm trying to crop and resize to clean up the edges as its a VHS transfer, plus a couple of other things to run on it

All the filters I've used work fine, but as soon as I use crop or resize, the output video is badly scrambled

If I use CropBottom(12) to remove the just VHS lines from the bottom things are fine, but if I use ANY crop or resize command or external crop/resize filter it scrambles the video every time

I've tried deinterlacing it, as it looks like its interlaced but that makes no difference. I've also tried Telecide


According to the properties from MediaPlayerClassic, from the source video they are :

Video Size : 768x576

Video: MPEG2 Video 704x576 (4:3) 25.00fps 9586Kbps [Video]
Audio: Dolby AC3 48000Hz stereo 256Kbps [Audio]
Subtitle: DVD Subpicture [Subtitle]


From the attempted resize/crop, again according to MediaPlayerClassic properties, they are :

Video Size : 704x576 (AR 4:3)

Video: MPEG2 Video 704x576 (4:3) 25.00fps 6420Kbps [Video]
Audio: Dolby AC3 48000Hz stereo 256Kbps [Audio]
Subtitle: DVD Subpicture [Subtitle]

GPSpot says its a PAL 25.00 frame source, so nothing strange there


I went through my filter chain removing each filter in turn, and worked out if I don't do any resizing or cropping everything turns out fine. But I need to crop and resize to remove the edge damage and lines from the source


Source Link : http://hyperupload.com/download/021ff1fc18/VTS_01_1.VOB.html


Output Link :

http://hyperupload.com/download/021ff1fc91/VTS_01_1.VOB.html


Each file is less than 7MB and runs for about 10 seconds, just to test the filters I'm trying out

While I'm here, suggestions as to how to improve this even further will be very gratefully recieved

For those that can't guess the movie, its Lemon Popsicle and I have the entire set to try to clean up. They are all basically the same quality as the tapes are about 20-25 years old now which I don't have access to

TDeint() : If interlaced, not 100% sure
CNR2()
RemoveGrain(mode=17)
RemoveDirt()
Lanczos4Resize(720,576,4,2,-8,-12)
HDRAGC(coef_gain=0.8,coef_sat=0.8,min_gain=1.0,max_gain=3.0,corrector=0.7)


That script gets you an unwatchable scrambled mess

But, if I use this

TDeint() : If interlaced, not 100% sure
CNR2()
RemoveGrain(mode=17)
RemoveDirt()
CropBottom(12)
HDRAGC(coef_gain=0.8,coef_sat=0.8,min_gain=1.0,max_gain=3.0,corrector=0.7)

Everything turns out fine, but then the video in now not the correct size, hence the resize

I've resized video before with no problems, in fact another of the Lemon Popsicle films I tried crops and resizes fine


Even if I just run a single filter of simply Crop(4,2,-8,-12) or a simple BicubicResize(768,576) you still end up with scrambled video, but a single filter line of CropBottom(12) again works with no problems

[steptoe]

Solved it myself, but I still don't understand why it scrambled it so badly though

Running it through DVDBlanker in preview mode confirmed the video is interlaced, so at least I now knew I definately had to run a deinterlacer on it

Also I took another look at the video size source which is 704x576 and used that for the resize values

It resized and I cropped to what I wanted in removing VHS lines and minor edges imperfections perfectly without scrambled it again

So I assume trying to resize it to what MediaPlayer Classic gave as the video size screwed things up in a big way, but using the actual video size of what the source was of 704x576 solved everything