Interlaced source encoded as progressive?

[MagicSparky]

Hello all,

I have a videoclip which I want to restore for a friend of mine.
Some details of the clip:
WMV-File, 640x480, 25FPS, constant framerate.

This clip is fully progressive but has heavy interlaced artifacts in it. Another friend of him must had doing something wrong, as he encoded the source to wmv. Now I want to help to get a little bit better results.

It seems like the clips were originally captured interlaced but encoded as progressive without deinterlacing before?!
Is it possible to restore them maybe with some Avisynth tricks. The original source is not available anymore.

Thanks in advance.

[aedipuss]

take a look at a single frame. are the artifacts encoded into it and not just when playing it normally? if so, without the original source there isn't any way to remove something encoded into the frames.

[MagicSparky]

Yes, they are encoded into a single frame.
Are there really no methods to revert or clean this a bit?

[jagabo]

You can recover the video if the two fields haven't been co-mingled (colors will continue to be a little blurred). But 25 fps indicates a PAL source so it's likely the video has been resized to 480 lines from the original 576. That would have mixed the two fields together and eliminated any possibility of recovery. It's possible the frame was cropped instead of resized. If that's the case it could be restored.

If you post a frame grab or a short sample it will be possible to tell you which is the case. I recommend you use VirtualDubMod. Open the video. Navigate to a frame with obvious comb artifacts. Then select Video -> Snapshot Source Frame. Save as PNG.