QTGMC issues on PAL capture

[agisthos]

I am new to his and have just started doing some PAL raw VHS capture to AVI.

You all say best practice is to do the de-interlacing via software, so I am testing different de-interlacing results. But when I try and use QTGMC the result is unwatchable flickering.

See here
https://mega.nz/folder/PNl1QayL#nfoCfNlbP1L1DG5vSWyung

The original file is 720x576 at 25fps interlaced.
Then look at the QTGMC and yadiffmod2 (double rate) outputs. What is wrong with them? Obviously I have made mistakes with the settings here.

The only way I got a 50fps de-interlace to work properly was using Handbrake and yadiff+bob. That one works fine. But anything I try in both Staxrip and Hybrid are coming out not correct. Yes I am using GUI's for Avisynth as I have not figured out this scripting stuff yet.

[jagabo]

Staxrip got the field order backwards (the video is TFF, Staxrip assumed BFF). Handbrake did an incorrect progressive conversion from YUY2 to YV12 before encoding -- causing ghosting of colors.

AviSource("original-file.avi") 
AssumeTFF()
ConvertToYV12(interlaced=true)
QTGMC()

[agisthos]

Thanks for that it all makes sense now.

I did do a search on the forum before posting this but did not know the key word is 'field order'. It seems my problem was also solved here, with the OP having the same issues using Hybrid.
https://forum.videohelp.com/threads/394294-QTGMC-and-stutter

This must mean industry standard for AVI capture is BFF?

[jagabo]

DV is BFF. But most other interlaced video I've dealt with has been TFF.

[emcodem]

This must mean industry standard for AVI capture is BFF?

No it is just more like bottom field is at some points kind of default assumed in avisynth (which does not mean in the industry). E.g. AssumeFrameBased will automatically assume BFF (so BFF is default). Actually it is about the importer that you are using. Some importers might even be correctly detecting and forwarding the info into avisynth (if your container provides that info)

You might want to know, avisynth started off with support for avi files a very long time ago. At this time, a widely used codec was dv which was bottom field. The AVI container is not able to store any "interlacing" based information. I imagine this is one reason why "bottom" is kind of default in avisynth, causing us trouble until today there and where.

If you have time, you can try out our software http://ffastrans.com you can use qtgmc there in the deinterlace filter and it will do it's best to detect and set the correct interlacing for you.

[agisthos]

If you have time, you can try out our software http://ffastrans.com you can use qtgmc there in the deinterlace filter and it will do it's best to detect and set the correct interlacing for you.

I downloaded that one yesterday actually, looking forward to trying it out.