PAL Speedup / 24th frame repeated questions

[ArtOfLosingMFZB]

I have a video that I'm not sure is suffering from PAL speedup or not. If it's not speedup, than it's the ghost-image technique in which the 24th frame is repeated to fit the 25 FPS PAL standard. I have a suspicion that it's the speedup but I'm not certain. Is there an easy way to tell? I hear the ghosting technique is pretty obvious, in fact I have another PAL video which I'm almost positive suffers from it, the pauses every second are pretty obvious and very annoying.

So, my questions are:

1.) Is there an easy way to determine which it suffers from?
2.) I know there's a way to convert PAL XviD's that suffer from speedup to 24 FPS, so is there a way to fix PAL XviD's that are ghosted?

Thanks in advance for any help.

[redwudz]

You could open it in VirtualDub (Mod) and step through it one frame at a time and see if a frame is duplicated. You can probably also use VD or similar to 'decimate' the video and cut out every 25th frame. A Avisynth script would probably be better, though.

[manono]

1.) Is there an easy way to determine which it suffers from?

The preferred method is with an AviSynth script as rarely do you get frame duplication, but more often field blending and you have to separate the fields to be sure of what you have. I suppose VDub can also separate the fields, but AviSynth is by far the best way to, first, determine what you have, and, second, to fix it.

Also, if every 25th frame really is a repeat, then it's not speeded up, but is the same length as the film source. Yes, it plays at 25fps, but there's also an additional frame every second. The net result is it being the same length as the source, but converted to the PAL standard. It's very rare to convert to PAL using that method. If you don't know what you have, give us a 10 second piece of the source, a piece with movement.

Open a VOB in DGIndex and use the [ and ] buttons to isolate a small section. Then File->Save Project and Demux Video. Upload the resulting M2V to a 3rd part hosting site, one such as MediaFire, and then post the link here.

is there a way to fix PAL XviD's that are ghosted?

Yes, but only using AviSynth.

[jagabo]

I haven't seen any smart frame rate converters for VirtualDub. If you use its built in frame rate conversion it will remove 1 of every 25 frames to convert to 24 fps. But it will not necessarily remove the duplicate frame, it will just pick one out at random. So your video is likely to get more jerky, not less.

Your only hope of removing the duplicate frames is to use a smart decimator in AviSynth -- Decimate() or TDecimate().

[ArtOfLosingMFZB]

Looking through the videos in VDub, they don't appear to have a 25th frame repeated. Seems to be blending though. Here are samples from the files in question:

http://www.mediafire.com/?utiyd21fz4y
http://www.mediafire.com/?okzizjzwqnj

Thanks for the help, I really appreciate it.

[manono]

I apologize for missing the part where you said these are XviD AVIs. They've already been deinterlaced and nothing can be done at this point. If you had gotten them while still interlaced, direct from the capture as MPGs perhaps, then something could have been done.

If field blended, only if still interlaced can they be repaired, sort of. Unblenders depend on at least one of the field pairs being "clean" and unblended for them to work their magic. Once they've been deinterlaced and made progressive, it's pretty hopeless.

[ArtOfLosingMFZB]

Ahh, I see. Alright, well thanks for all the help.