Help identifying VHS/VCR artifacts?

[Mr.We]

Hi Guys,

I've just started my journey transferring some old VHS tapes, on the first tape i've noticed a couple of artifacts, I would love to learnt whether they are caused by the actual tapes or perhaps my VCR?

The first artifacts are these faint vertical lines/bands that appear, sometimes they slowly move across the frame, sometimes they're static like in the jpeg attached. They seem to usually be more frequent on the left side of the frame.

The second type of artifact I've learnt is ghosting, the questions is, was this effect caused by the VCR upon recording back in the day, or could it be a playback problem with my current VCR? I'm using a Sony SLV-EZ 2000s if that signifies anything.

I hope someone can help!

[sanlyn]

Welcome to digitalfaq!

Quote:

Originally Posted by Mr.We

I've just started my journey transferring some old VHS tapes

It might seem like a minor point, but but we need a better term that tells us more about what you're doing. Analog tape isn't "transferred", it's either recorded or captured to other media. Are you using a PC capture device? What format are you capturing to (lossless? DV?). Are you recording from a VCR to MPEG or some other lossy codec?.

Unfortunately we can't give a very be very precise answer. We have to know what you mean by "transfer". It's difficult to ascertain what's happening from still images, which here appear to be cropped. The darkish bands are visible in the first photo, along with bad chroma noise and horizontal rainbows. If the bands are actually moving during play, we can't play a still image to see it. The second photo shows apparent line timing errors (some warped and ragged-edged verticals), and the edge ghosts and edge ringing halos are possibly from the original broadcast. Vertical bands are visible in the second photo as well.

We could tell you how to post a short edited, unprocessed sample of video in this forum that tells us much more, but we don't know what video format you're working with.

[lordsmurf]

Oh, I think "transfer" is fine. I use it myself quite often as a general term. How you transfer is either capturing (to computer) or recording (with DVD recorder).

For interference (ghosting, etc) patterns, sample clips are needed.

From the simple image, neither look too difficult to remove or improve. But again, to identify it, a clip is needed.

You can attach up to 99mb to the forum. Please do so.

[sanlyn]

Agreed, I often used "transfer" or even -- eek! -- "converted".

What I meant was, transferred to what format? The format will determine what one can advise on how to make a short edit without re-processing everything and confusing the issue.

Those vertical bars look like OTA transmission noise.

[lordsmurf]

Oh, yeah, duh.
tape > avi? mpeg? mp4? something else? I must be tired if I overlook that.

@OP, again, post some clips. We'll look at them.

[Mr.We]

Thanks guys, sorry for the lack of info, I was hoping it might be an easily identifiable phenomenon.

You're going to hate me for this but i'm capturing on a Mac through an Elegato Video Capture ADC straight to Mpeg4, although the grabs I uploaded were from my first capture to h.264 in a mpeg4 wrapper before I realised I could capture direct to Mpeg4 at a higher bitrate.

For the video samples i've uploaded below, i've cropped the Elegato captured mpeg4 (not.h264) video in Mpeg Streamclip using the apple mpeg4 compressor at 100% quality which I believe should be the same quality as the original capture file, although VideoSpecs says these cropped videos have a bitrate of 9573kbps vs the originals 2630 kbps - I guess upsampling won't change anything though right?

Here are dropbox download links:

VHS vertical bars video sample

VHS ghosting video sample

Thanks again for your help!

[sanlyn]

Thanks for the samples.

Mac. Hmm. Not much you can do with bad video on a Mac. Too bad these samples have been damaged with so much re-processing. The defects are pretty well embedded. Color is oversaturated and looks cooked. I'm scratching my head over how your setup managed to encode both videos at exactly 24.38 fps. The bars sample looks pretty jumpy, with a lot of wiggling going on (damaged tape?). What did you use to remove telecine from the originals? Shouldn't Hollywood movie-sourced video run at 23.976 fps after telecine is removed?

The vertical hum bars are either RF noise or, more likely, transmission noise. If those bad edge ghosts and halos looked that way on the original tapes, they're obviously on the tape itself. If not, they got there (or were made worse) by playback hardware and re-encoding software. Unfortunately we're still doing some guessing here, because these are not original samples. Someone might be able to come up with ideas for fixing, but I doubt you could do it in your Mac.

Quote:

Originally Posted by Mr.We

For the video samples i've uploaded below, i've cropped the Elegato captured mpeg4 (not.h264) video in Mpeg Streamclip using the apple mpeg4 compressor at 100% quality which I believe should be the same quality as the original capture file

No way.

Quote:

Originally Posted by Mr.We

I guess upsampling won't change anything though right?

Not right. Sorry.

This would be a whole lot of repair work, and you'll need Windows. I suggest that you need a better VCR, too.

If you expect to do any image mods or cleanup on video captures, don't capture to lossy codecs--it just makes the work tougher, if not impossible. h.264 isn't designed for editing, it's a lossy interframe final delivery format. The vertical bars sample cut was re-encoded yet again to make the sample. It contains only a single GOP of 99 frames, indicating that it was from an earlier encode that used long GOP's poorly suited for editing.

[Mr.We]

Thanks Sanlyn. I'm not sure what you mean by what I used to remove telecine from the originals, i've only played back the vhs through the Elegato Video Capture ADC and exported as the mpeg4 file through Elegato Video Capture software before cropping in Mpeg Streamclip. Fortunately I can adjust the saturation, but yes that's a very odd framerate... I guess i'd have to further process to get back to the correct framerate?

I've just tested ripping some other tapes, including some commercial VHS (just for testing purposes of course) which don't have these artifacts, so i'm assuming it's to do with that particular VHS tape as it was initially recorded. I'm not too fussed about removing these artifacts for now, just wanted to make sure my VCR isn't adding weird artifacts to my transfers, although I am looking for a decent quality Pal S-VCR player.

Thanks again!

[sanlyn]

VHS is interlaced. If it's from a film-based movie, it's really progressive video that is hard-telecined (periodic frames that look interlaced) Or it could be 25fps interlaced PAL made from a progressive 23.976 original and speeded up. We can't say without the original capture. Elgato on a Mac isn't the proper tool for what you're doing.

More processing using a lossy codec will make it worse.

[lordsmurf]

Pet peeve of mine:
It is not "ripping" when you capture tapes. The term "ripping" is specifically reserved for extracting data off of an optical disc when the data is held in a method not understood natively by computers. For example, CD audio (non-files), or DVD-Video (UDF in specific disc structure).