How to post-process horizontal stripes in Video 8 capturing

[ringo1]

Hi!

The following is the same frame captured from the analog outputs of a Bauer VCC 816 AF camcorder and from the analog outputs of a Sony TRV-210E Digital-8 camcorder:

Bauer VCC 816 AF:

[Attachment 56816 - Click to enlarge]

Sony TRV-210E:

[Attachment 56817 - Click to enlarge]


The Sony obviously does some sort of post-processing on the stripes at the bottom of the frame, so they become far less obvious.

Can anyone tell me how to do this in software (VirtualDub / AviSynth) ?

And what is the name for the phenomenon of these stripes?

Cheers
Ringo

[aedipuss]

dirty/bad video heads and/or the tape losing it's magnetic properties. the sony just reads the info left on the tape better it's not processing it.

[dellsam34]

The Sony obviously does some sort of post-processing on the stripes at the bottom of the frame, so they become far less obvious.

Can anyone tell me how to do this in software (VirtualDub / AviSynth) ?

And what is the name for the phenomenon of these stripes?

Cheers
Ringo

That processing called DOC (Drop Out Compensation), There is a chip inside VCR's and camcorders called DOC circuit that process that by replacing bad scan lines with good ones from neighboring lines, Obviously Sony does have a better processor than the other brand, they invented the format after all.

[jagabo]

I agree with dellsam34. If you separate the fields and view them separately you can see that the previous scanline is repeated, sometimes for several scanlines in a row, whenever one of the dropouts would have occurred.


[Attachment 56827 - Click to enlarge]

[ringo1]

Drop Out Compensation, thanks for the cue!

Am I right when guessing that drop out compensation cannot be done in post-processing?

[jagabo]

Am I right when guessing that drop out compensation cannot be done in post-processing?

It depends on how bad they are. We would need a video sample to say for sure.

[ringo1]

It depends on how bad they are.

I haven't found frames worse than the one I posted and I'd guess that these kind of frames occur 20 times per tape along with many more frames with less drop outs.

But I definitely can't afford any kind of manual processing. I've got a hundred tapes to capture.

[aedipuss]

have you tried capturing after using a head cleaner?

[jagabo]

It depends on how bad they are.

I haven't found frames worse than the one I posted and I'd guess that these kind of frames occur 20 times per tape along with many more frames with less drop outs.

Many of the algorithms for fixing these types of dropouts look at adjacent frames as well as adjacent scanlines. So a video sample is required. But if the image you posted is one of the worse I think most of it can be fixed in software -- and with better results than the Sony VCR delivered.

[ringo1]

have you tried capturing after using a head cleaner?

No, I haven't. I've got such a tape with a isopropyl sponge, but haven't dared to try it.
And the propblem is obviously on tape, because it appears when played in two different camcorders, so will a head clean help at all in this case?

So a video sample is required.

I'm afraid I can't post one for privacy reasons currently.

- and with better results than the Sony VCR delivered.

Are you sure? Doesn't the playback device have information that post-processing cannot take from the video?

[themaster1]

I'm afraid I can't post one for privacy reasons currently.

I like these old 80's wedding orgies. you can post please ?

[jagabo]

Search the forums for "comets" and "dropouts" for examples of how to remove such noise. You'll need to use AviSynth.

Regarding privacy issues, you can't find a shot with the problem that doesn't have identifiable people/places in it?