Help identify VHS artifacts shown in screens

[Okys]

Hello guys.
I got a problem and because my primary language is not english, i don't know how to describe it and search for an answer.
What i am trying to do, is save material from old, defectively recorded VHS tapes to my PC's hard drive in a format which is good for viewing. I have tried many things on improving the quality of those old records, but there is one thing I can't get rid of.

Here you see the picture i get in any video player and no mater what i try or re-encode, it's always like this:


When i add this video to Sony Vegas 9, the artifacts dissapear while playing and appear again while paused:
Screen here:


If anyone has a solution on how get rid of those artifacts, or a corect description of them in english, i will be very thankful.

[SHS]

Part of the problem is compression your using some of it is mosquito noise
How are recoding the clip

[2Bdecided]

Those white flecks are called comet tails. They are usually due to head wear when recording or playing back.

You also have interlacing (use a player that deinterlaces when playing, like Vegas is doing, and like your DVD/TV will do).


Maybe thought Vegas only shows one field when playing, and both fields when paused. Maybe the comet tails are only in one field. Maybe they are due to capturing, and not on the tape. Can you see them at all when you play the tape straight into a TV (not PC)?

If you upload a short sample it may make it easier to understand what is happening.

Cheers,
David.

[Okys]

Thanks a lot guys. David, it's exactly what you said. Vegas were only playing one field, and with deinterlacing i can get rid of comet tails. These videos were captured a long time ago and unfortunately original old tapes are not available anymore.
Good it was only one of heads broken. Problem is solved now!
Thanks.

[2Bdecided]

Glad to help. That sounds like the simplest solution, though the result will only be 25p, not 50i (so it can never be deinterlaced to 50p) - so you've lost half the spatial and temporal resolution. It will look OK though, especially on a PC. It might look a little strange on a TV, because the movement will not be smooth.

A full restoration (keeping both fields, and fixing the broken one) would be far more difficult, but it might be possible with AVIsynth. There are some video fans over at the doom9 forum (some also post here on videohelp) who love a restoration challenge like this one.

Cheers,
David.

[jagabo]

A full restoration (keeping both fields, and fixing the broken one) would be far more difficult, but it might be possible with AVIsynth.

That's your best bet. Upload a sample and some people here will give it a go.

[vhelp]

its unfortunate that you no longer have the tapes to replay them in a different vcr to recapture from.

the first pic showed the artifacts (commet trails) because that frame(s) has them, while the next frame(s) did not. but it looks like the sony editor is deinterlacing inside the time line, so you are not seeing as big an implact on the artifacts. as was note earlier, the editor these artifacts may show in either (odd or even) or both fields. it all depends on the tape and the machine it was played in. you will have to learn avisynth scripting and the various plugins (filters) to remove some or most of them from each tape. do some searches for "comets" and you may find a few how-to articles on this issue.

[jagabo]

Yes, it's too bad you don't have the original tapes and the ability to capture them again. Comets are usually different at each playback so they can be removed with multiple caps and a median filter.

[2Bdecided]

it looks like the sony editor is deinterlacing inside the time line

it is deinterlacing for preview - it says so if you look closely. project = 720x576x32 25i; preview = 360x288x32 25p. It's the 1/4 resolution preview that drops half the fields.

I often do this to HD footage for quick uploads to the net (you get 960x540 with a little aliasing but don't have to worry about the choice of deinterlacer), but never with SD footage as the result is too low resolution for my liking.

Cheers,
David.