PAL UK VHS VirtualDub capture audio slow, lost sync?

[Maxwellgood]

I've been trying to capture some VHS, for the most part I haven't had issues in the past, but there will be issues with the audio on the odd tape. Upon playback of the later parts of a captured video, the audio will go out of sync, with the speed of the audio slowing down and speeding up.

Could this be down to the large amount of data being captured and written?

Current setup:
VCR: Samsung SV-251B - Scart
CAPTURE DEVICE: Scart to I-O Data GV-USB2
SOFTWARE: VirtualDub 1.10.4
PC: Win 10, i7 6700K, 16GB RAM, SSD x 3

While I'm here, would anyone have any recommendations for a codecs which preserves quality and takes up less disk space? I currently use no recompression (YUY2)

[lordsmurf]

This is easy: you lack any form of TBC in your setup.

Video capture requires more than an old VCR, and a cheap capture card. What happens is dropped frames, and thus audio sync error s (as the audio captured continuous, while the video does not).

The slow/fast is the computer attempting to "fix" the audio offset, but it never works.

Take a look around the forum.
A proper workflow = VCR > TBC > capture card
And not just any random VCR/TBC/card, but specific models known to output quality. Or at least not be junk, if you go the budget route.

[Maxwellgood]

Quote:

Originally Posted by lordsmurf

A proper workflow = VCR > TBC > capture card
And not just any random VCR/TBC/card, but specific models known to output quality. Or at least not be junk, if you go the budget route.

Hey lordsmurf, thanks for the fast response! I've read up on a lot of your troubleshooting advice on these forums.

I did own a JVC TBC VCR (which I paid a pretty penny for) however it was faulty and I had to return it... I would love to be able to afford a new Super VHS TBC VCR right now.

Are there any settings within Virtualdub that might remedy it temporarily, or, are there any alternative ways which the software can interpret the audio which might produce different results?

Long-term I'm looking at a better setup, but right now I have to return these VHS tapes to the library, and I might not be able to retrieve them again, so I was hoping to get half-decent captures. The audio seems to be my only issue.

[lordsmurf]

Software cannot fix this. Hardware is required.

[Maxwellgood]

Quote:

Originally Posted by lordsmurf

Software cannot fix this. Hardware is required.

Gotcha thanks.

Any recommendations for high-quality low disk space codec alternatives?

[lordsmurf]

Seeing as how 22tb HDDs are now about $350 taxes/shipped, and SSDs are at all-time low prices, there's really nothing "large" about standard Huffyuv, which is about 35gb/hour.

The next choice would be 4:2:2 MPEG-2 @ 15mbps+ (better is 25-50mbps, but then you start to approach Huffyuv sizes). Remember to keep the GOP low.

[Hushpower]

The IO Data GV-USB2 is a good digitiser. It is my go-to digitiser.

Lordsmurf's recommended Virtual Dub for capture is version 1.9.11.

Some people have had success with audio sync by capturing with AmarecTV.

Good capture codecs include HUFFYUV (Lordsmurf can provide instructions on how to get that installed) and UT Video. I use MagicYUV but it is not free.

Ultimately, you need a video stabiliser of some type; either a SVHS VCR with Line TBC or a Panasonic DVD recorder which you pass the video signal through.

Quote:

Originally Posted by Lordsmurf

The next choice would be 4:2:2 MPEG-2 @ 15mbps+ (better is 25-50mbps, but then you start to approach Huffyuv sizes).

How is the OP going to achieve that?

[Maxwellgood]

Quote:

Originally Posted by Hushpower

The IO Data GV-USB2 is a good digitiser. It is my go-to digitiser.

Lordsmurf's recommended Virtual Dub for capture is version 1.9.11.

Some people have had success with audio sync by capturing with AmarecTV.

Good capture codecs include HUFFYUV (Lordsmurf can provide instructions on how to get that installed) and UT Video. I use MagicYUV but it is not free.

So I took some steps to help improve the capture.
1 - Downloaded v1.9.11. of Vdub
2 - Installed trial version of MagicYUV
3 - Captured using V1.9.11, and Magic YUV 4:2:2 codec, I did a comparison... see attached screenshots.

I suspected that quality of the capture may have been impacted by my PC performance.

For V1: Usual setup of two display monitors, with applications running in background.
Frames Dropped: 3847
Frames Inserted: 121

For V2: Only used lower resolution display monitor, with no applications running in the background.
Frames Dropped: 0
Frames Inserted: 14

So, it looks like my computer's performance was impacting the capture video! I'm not sure if I should be focusing in on frames to measure capture performance, what other factors would indicate how well the capture is performing? (Sync, data rate, etc?) The video does look better on V2.

Unforunately the audio sync had similar results on both tests, with it speeding up and slowing down on different places on each. So yes it will likely require a TBC of some kind to remedy.

I'd really like to test this with Amarec but I'm having some difficulties with the software, error messages such as "ICCompressGetFormat" and "ICCompressGetFormatSize".

[Hushpower]

Quote:

error messages such as "ICCompressGetFormat" and "ICCompressGetFormatSize".

I haven't come across those but a Google shows them popping up when the AMV4 codec is selected on the Recording tab. Check you've got "Other Codec" ticked, and click "Update Codec List" then the codec you are after. If it's Magic, choose MSY2, MagicYUV422.

[Maxwellgood]

Quote:

Originally Posted by Hushpower

I haven't come across those but a Google shows them popping up when the AMV4 codec is selected on the Recording tab. Check you've got "Other Codec" ticked, and click "Update Codec List" then the codec you are after. If it's Magic, choose MSY2, MagicYUV422.

Got it working, and, AmaRecTV's capture doesn't have ANY audio issues! Thank you for the suggestion!

Quote:

Originally Posted by lordsmurf

Software cannot fix this. Hardware is required.

Care to explain

[lordsmurf]

Data is lost at capture, due to bad/unclean signal, nothing to correct in software.

AmaRecTV "fixing" is not actually correcting the issue. The issue is just hidden, and can rear its ugly head again later. That software was creating for live-broadcasting video games in Japan, and broadcasting requires sleight-of-hand to not lose sync on data transmit.

I still think "AMV" in the codec stands for "anime music videos", which was big at the time, in the 2000s. A mix of Japanese video games and anime, with K-Pop type music. It's an ancient site that still exists: https://www.animemusicvideos.org
At the time, it was a source for some pretty bad info on capturing (disable dropped frame reporting), butcher filtering, butcher deinterlacing. The community broke down in the 2010s, shell of itself now, the founder stepped down as admin, etc.

AmaRecTV, AMV4, was a product of the scene of the era. It was never intended for capturing VHS home movies.

[Maxwellgood]

Quote:

Originally Posted by lordsmurf

Data is lost at capture, due to bad/unclean signal, nothing to correct in software.

AmaRecTV "fixing" is not actually correcting the issue. The issue is just hidden, and can rear its ugly head again later. That software was creating for live-broadcasting video games in Japan, and broadcasting requires sleight-of-hand to not lose sync on data transmit.

I still think "AMV" in the codec stands for "anime music videos", which was big at the time, in the 2000s. A mix of Japanese video games and anime, with K-Pop type music. It's an ancient site that still exists: https://www.animemusicvideos.org
At the time, it was a source for some pretty bad info on capturing (disable dropped frame reporting), butcher filtering, butcher deinterlacing. The community broke down in the 2010s, shell of itself now, the founder stepped down as admin, etc.

AmaRecTV, AMV4, was a product of the scene of the era. It was never intended for capturing VHS home movies.

Ha, I submitted an AMV to that site in the very early 2000's, I used Windows Movie Maker with some dodgy Divx encoder, things, cannot really remember... Funny how that codec name stuck.

VCR with TBC is my next priority, but for now, it's valuable for me and others to know that AmaRec is a good alternative to VirtualDub if you are having audio sync issues while capturing VHS, especially if you do not own and cannot afford a TBC.

[Hushpower]

Quote:

Originally Posted by Lordsmurf

AmaRecTV "fixing" is not actually correcting the issue. The issue is just hidden, and can rear its ugly head again later.

Hang on, that's what all this other stuff is doing too. Line TBC is "fixing" the issue. Frame TBC is "fixing" the issue. Flash, expensive VCRs are "fixing" the issue.

You poo poo OBS and other consumer software because it doesn't give the right result but you're sledging the only software that is giving the right result and defending a dud. If somebody came on here saying they have audio sync issues with OBS you'd be screaming from the rooftops how bad it is, yet VDub is doing just that and there's not a peep of criticism.

Hard to follow sometimes...

[lordsmurf]

Quote:

Originally Posted by Hushpower

Hang on, that's what all this other stuff is doing too. Line TBC is "fixing" the issue. Frame TBC is "fixing" the issue. Flash, expensive VCRs are "fixing" the issue.

You poo poo OBS and other consumer software because it doesn't give the right result but you're sledging the only software that is giving the right result and defending a dud. If somebody came on here saying they have audio sync issues with OBS you'd be screaming from the rooftops how bad it is, yet VDub is doing just that and there's not a peep of criticism.

Hard to follow sometimes...

Yes, it is hard to follow.

But it's because too many people are trying to use software and hardware in ways never intended, mostly in an effort to be cheap. Everything from using "broadcast" software for capture, to using DVD recorders as TBCs, to using cheap Chinese converters as capture cards. The video signal gets lost, damaged, and butchered.

TBCs correct in dedicated hardware at the signal level.
Software on a computer cannot access that signal. (Correcting in software is what RF methods try to do, and it's still far from fully/consistently viable.)

OBS and AmaRecTV are both "broadcast" software -- and that term is used very loosely. It elicits eye rolls from those who actually work in broadcast. It's just streaming software.

OBS operates mostly as digital-source screen recording, and "captures" from within the preview graphics display layers. It works best with webcams/cameras (as designed), and quite poorly with analog capture/ingest cards (a tack-on feature added later).

AmaRecTV is somewhat like a beta version of OBS. It was created for the analog source era (mostly video games). It does have have some sort of card hardware/driver access, but the actual capture is apparently not. It does operate somewhat differently from VirtualDub defaults, but VirtualDub can be adjusted (not suggested) to mimic the behavior.

Because of how these software operate, "no dropped frames" is essentially because you're "capturing" a preview where the drops already occurred. That's essentially what the non-TBC frame sync does in DVD recorder output. To date, all discussion of AmaRecTV comparisons have been to DVD recorders, not actual TBCs.

All of this has downsides with signal integrity, and video data is lost. For most users, it matters. Yes, it's "in sync" and "reports no drops", but it's not really accurate.

I do plan to run full tests myself, comparing these methods for others to see, but it won't be this year.

Now, all that said, it's important to note something else:

There are definitely situations where you run into minimal loss.

But it's the exception not the rule, and not everybody is an exception (in fact, most are not). If you're able to use AmaRecTV, in conjunctions with some sort of budget hardware combo (plain VHS VCR, ES10/15, non-crap capture card, etc), and get results that are decent (or at least not lousy), great! The better the hardware (S-VHS VCR with line TBC, frame TBC, best capture cards, etc), the less AmaRecTV is able to ignore/lose.

Again, most won't get that "benefit", but some are -- mostly PAL users, not NTSC. PAL and NTSC have different sorts of errors, and potential severity of those errors. In a broad/general sense. And again, it's mostly PAL users reporting certain successes, with certain card combo setups. The NTSC tend to fully fail further scrutiny.

I'd suggest some cards actually need to work with AmaRecTV, due to some sort of conflict with VirtualDub that incurs dropped frames. That's not VirtualDub's fault (similar to how cards are not to blame for Windows 10/11 rejecting cards), but merely an obstacle for capturing with some hardware.