VHS Playback "Glitchy". Trying to Cleanly Digitize Old Cassettes.

[Kong]

Hello folks. Hopefully, someone here will know how to address this.

Periodically, and with no consistency in timing or frequency, my VHS tapes will be playing normally, and then for about 1 second, will stop playback, then resume playback where it would have been if it had played back normally. Does this make sense?

I am trying digitize my old tapes (only selected portions though, so I have to watch each tape all the way through). But, I don’t want those glitches in the digital files.

Can anyone make a recommendation? I have cleaned the heads, to no avail.

Thanks

[dellsam34]

Without a visualization, it's hard to guess what might your problem be. Failure in VCR hardware, capture hardware, software, hundreds of combinations possible.

[Kong]

Without a visualization, it's hard to guess what might your problem be. Failure in VCR hardware, capture hardware, software, hundreds of combinations possible.

Okay... I will see if I cannot get an example uploaded. Can I do that? (It may take a few days.)

[Kong]

Without a visualization, it's hard to guess what might your problem be. Failure in VCR hardware, capture hardware, software, hundreds of combinations possible.

Okay... I will see if I cannot get an example uploaded. Can I do that? (It may take a few days.)

Might not matter. Thank you for the response, but it seems that the glitch is not actually recorded. It only seems to appear in my VidBox preview window.

Thanks!

Keith

[Kong]

I noticed tonight when playing back something I digitized.

I’m attaching a file.

[Alwyn]

Does the pause occur during repeat recordings of the same spot or is it random?

[Sharc]

I don't know that Vidbox thingy, but there are
- dropped frames
- poor realtime baserate deinterlacing (with blends and field glitches) + resizing on the fly
- wrong color space (709 instead of 601)
- Variable Frame Rate (VFR)

What was your source? Tape? TV?

Revisit your capture setup.

[aramkolt]

Would have to guess it is your computer or hardware not quite keeping up with the hardware. The VCR isn't actually "stopping playback," your capture card is choking up on the signal it is receiving. Preview windows keeping up is often a problem, so if you have a way to disable the live preview, that might solve your problem by itself - maybe. If you need a preview, you'd probably be better off using a separate monitor and one of the other available outputs like composite if you're capturing via S-Video, or if your machine just has composite, you could use the RF output and an older TV.

Did you do any processing of the captured file to post the sample? Frame rate is incorrect (shows 27.93), but that could be it choking on the video.

I do have a vidbox for testing, but I haven't actually taken it out of the packaging. Vidbox is interesting because it also is Mac compatible (or has Mac compatible versions) and supposedly works with modern Macs also. Seems like from the site it captures into MP4 format with the provided software, but I think I recall it being compatible with other capture software and you might be able to capture in interlaced. I also think I recall it using some of the same drivers as the ATI600, but I could be mistaken.

What's the full capture chain? Seems like from what I'm seeing in the sample that at least a line TBC was probably in use. Or if there was no line TBC, the vidbox seems to do pretty good with horizontal line stability.

[Kong]

Does the pause occur during repeat recordings of the same spot or is it random?

It is random.

[Kong]

I don't know that Vidbox thingy, but there are
- dropped frames
- poor realtime baserate deinterlacing (with blends and field glitches) + resizing on the fly
- wrong color space (709 instead of 601)
- Variable Frame Rate (VFR)

What was your source? Tape? TV?

Revisit your capture setup.

VHS cassette is the source.

Hmm... I will see if there are options that can be controlled. Thank you.

[Kong]

Would have to guess it is your computer or hardware not quite keeping up with the hardware. The VCR isn't actually "stopping playback," your capture card is choking up on the signal it is receiving. Preview windows keeping up is often a problem, so if you have a way to disable the live preview, that might solve your problem by itself - maybe. If you need a preview, you'd probably be better off using a separate monitor and one of the other available outputs like composite if you're capturing via S-Video, or if your machine just has composite, you could use the RF output and an older TV.

Did you do any processing of the captured file to post the sample? Frame rate is incorrect (shows 27.93), but that could be it choking on the video.

I do have a vidbox for testing, but I haven't actually taken it out of the packaging. Vidbox is interesting because it also is Mac compatible (or has Mac compatible versions) and supposedly works with modern Macs also. Seems like from the site it captures into MP4 format with the provided software, but I think I recall it being compatible with other capture software and you might be able to capture in interlaced. I also think I recall it using some of the same drivers as the ATI600, but I could be mistaken.

What's the full capture chain? Seems like from what I'm seeing in the sample that at least a line TBC was probably in use. Or if there was no line TBC, the vidbox seems to do pretty good with horizontal line stability.

Changing preview set-up is not an option at this time. I need to use my Mac (2020 MBP, running Sequoia 15.7.2) and its monitors.

No... I didn't change anything in the sample. If it was at 27.93, that was the likely the Vidbox's doing.

Capture chain, if I read you correctly, is simple: VCR > VidBox (via RCA cables) > CalDigit dock > Mac (via TB3).

Bear in mind, that this problem has only surfaced in the past few months. I’ve been using this since ~2020, and on an old Mac, and I did not have these 'glitches'.

[Kong]

I tried updating its drivers. Not sure about the last time I did that or how recently these drivers were themselves updated by Vidbox. There were no other settings to adjust, unfortunately, certainly none of the things mentioned by you guys. But, this problem is only a few months old, and I’ve had this thing for ~ 5 years.

Vidbox tech support sent me this...

• If you do not shut down or reboot regularly, attempt power cycling the Mac:
1 Shut down the Mac.
2 Disconnect all power and USB connections, including hubs/adapters.
3 Let it rest unplugged for 10 minutes.
4 Reconnect and try again.
• Are you able to test any changes to the USB connection?
◦ Another USB-A port if using a USB hub
▪ It can sometimes also help to disconnect other devices from a hub, particularly high-bandwidth devices (e.g. other video devices, webcams)*and devices that may be transferring a lot of data (e.g. external drive).
◦ Another USB-C port for your adapter/hub
◦ Another USB cable
◦ Another USB adapter
1
• If available, test*with a separate VCR or with a DVD player. DVD players are particularly useful in that digital video sources handle information differently than analog sources, so the results would be particularly telling on whether it will be due to the source device and media or with the VIDBOX product and Mac side.

Thoughts?

[Sharc]

Thoughts?

They seem to have noticed your dropped frames. So basically they advise you to free the PC from any other tasks loading the CPU, including those running silently in the background. Similar for the USB connections: Avoid sharing with other devices. Also don't move the mouse during capture.
Do you have an aggressive virus scanner in place? It can be ressource demanding and cause dropped frames. Disable it temporarily.
If you can, disable the on-the fly-deinterlacing and resizing. Switch it off and deinterlace in post processing, after capture.

[Kong]

Thoughts?

They seem to have noticed your dropped frames. So basically they advise you to free the PC from any other tasks loading the CPU, including those running silently in the background. Similar for the USB connections: Avoid sharing with other devices. Also don't move the mouse during capture.
Do you have an aggressive virus scanner in place? It can be ressource demanding and cause dropped frames. Disable it temporarily.
If you can, disable the on-the fly-deinterlacing and resizing. Switch it off and deinterlace in post processing, after capture.

I really don’t, but I do have a dock that provides the USB-A connections. That dock has several external HDs (not always running, mind you), two monitors, speakers, and an audio in from an external cassette deck.

Disconnecting some devices is one of the things I may look into. Unfortunately, I cannot change the settings of the device. The menu options in the Vidbox software are limited. It was $80, and that is all I could still afford to this day. I know there are much better (and much more expensive) options out there.

[Alwyn]

This YT video indicates capturing with Quicktime might be better:

https://www.youtube.com/watch?v=pcBiAXiK-5w

I second removing every external thing you can. Anything not required for the capture: disconnect it. Having dock with multiple HDDs attached gives me the heebygeebys.

[Kong]

This YT video indicates capturing with Quicktime might be better:

https://www.youtube.com/watch?v=pcBiAXiK-5w

I second removing every external thing you can. Anything not required for the capture: disconnect it. Having dock with multiple HDDs attached gives me the heebygeebys.

The heebie-jeebies, huh? May I ask why? LOL

I will check out that video

[Alwyn]

May I ask why?

A pause like that is probably caused by an overload somewhere in the recording process. Anything that is using computer resources unnecessarily might cause that overload.

[Kong]

May I ask why?

A pause like that is probably caused by an overload somewhere in the recording process. Anything that is using computer resources unnecessarily might cause that overload.

Wondering... While I’m going to see what that guys says in that video, I’m also thinking about a simple USB-A to TB3 adaptor, bypassing the dock entirely.

[Alwyn]

That sounds like a great idea. And remove everything from the dock apart from the capture HDD, use the Mac screen as the monitor. The Mac is encoding on the fly to MP4 (or Prores if you're using that YouTube QT option) so it needs to be as lightly loaded as possible.

[Kong]

That sounds like a great idea. And remove everything from the dock apart from the capture HDD, use the Mac screen as the monitor. The Mac is encoding on the fly to MP4 (or Prores if you're using that YouTube QT option) so it needs to be as lightly loaded as possible.

I’m not sure if I can use the Mac screen in that way. That is what the Vidbox software does. Never tried to capture with anything else. I don’t know of anything in the MacOS that can do this. Although.. I am actually about to watch that YouTube link now...

+ + + + + + + + + + + + +

About 30 mins later...

Okay, wow. Got the blue QT screen up and I’m ready to try some digitizing. I have not removed the hard drives from the dock, and I do not yet have that adaptor to bypass that whole chain. I do, however, want to see if there’s any difference doing things this way...

+ + + + + + + + + + + + +

About 10 mins later...

So far, so good -- except that I am not getting audio-out while recording. Trying to determine why. Otherwise, for ~5 mins, it went well (though the only real test is going to be with a 2-hr tape).