Bad audio on one VCR, bad frames on another

[Bizuser]

I've been successful in general converting old VHS tapes to DVD, using both an ATI capture card plus VDUB, and also the Canopus ADVC device with Adobe Premiere. The latter is my preferred method, due to no frame drops and no audio synch problems - not to mention, smaller intermediate files.

Anyway - ran into a weird problem with a tape this weekend. It's a VHS tape of a classical concert, commercial tape. The picture captured beautifully, but the captured audio was very bad when playing the DVD - terrible 'crackle' overlaying the audio. To be more specific, the audio would be very good, if it were not for a constant high-frequency crackle throughout the tape. Since this is a concert, I want to be able to play it loud! So I switched from my JVC S-VHS VCR (which has been my standard for this process) to my much cheaper Mitsubishi model. When capturing with this device, I get perfect audio but ... lots of video issues (frame skips/jerkiness/etc) (but not throughout the tape; just in certain spots). The tape is perfect quality - only played 5 times, no issues whatoever when viewing it.

It occurred to me ... this is the first commercial VHS tape I've tried to convert. Could I be running into some form of copy protection? The symptoms above don't sound like macrovision issues to me, but maybe it is. Is there a way to tell? Is there any 'marking' on a tape to indicate this?

I did veryify that the audio problems are in the captured avi file - thus, not an attribute of the mpeg encoding or playback.

Thanks!

[dphirschler]

You might be able to correct it on the good vcr b y running the audio through an attenuator. $8-$12 at Radio Shack.


Darryl

[Bizuser]

It wasn't that the audio was particularly loud. The 'meter' in the capture program was not going into the 'red' all the time, if that's what you are thinking. (I'm actually using scenalyzer live now, not premiere, but they are both similar).

Any thoughts about macrovision protection?

[davideck]

It doesn't sound like MV to me.
It sounds more like marginal Hi-Fi audio tracking. Optimum tracking for video doesn't always provide the same for the Hi-Fi audio track. You might try adjusting the tracking manually in hopes of finding an acceptable compromise between the video and audio quality.

Is your Mitsubishi a Hi-Fi VCR? Perhaps it is playing back the linear audio track.
How old is the JVC VCR? It might have an audio mix control that blends the linear and Hi-Fi audio together...

[Bizuser]

Thanks for the insight. The JVC is maybe 3 years old, sees VERY little use. It's an S-VHS unit. It has 'video calibration', but no manual tracking as far as I can tell (unlike my old beta machine!). I'm also not aware of any way to mix the hifi and linear - would that have to be an explicit option? I will play the video again, and just watch/listen, using headphones - if your theory is good, then I presume I should hear not-so-good sound, straight out of theVCR?

The older Mitsubishi ... will have to check tonight if it's HiFi or not. Certainly not S-VHS.

Hmmm .... maybe I should try turning OFF the 'video calibration' option ... could that help in this case?

I'd happily buy another player but I'm down to only about a handful of tapes I want to convert!

[davideck]

It has 'video calibration', but no manual tracking as far as I can tell

Many JVC VCRs provide manual tracking using the Channel Up/Down buttons...

I'm also not aware of any way to mix the hifi and linear - would that have to be an explicit option?

Audio mixing might be available within the menu structure...

if your theory is good, then I presume I should hear not-so-good sound, straight out of theVCR?

Yep...

[Bizuser]

Tried using channel buttons to manually track, no joy.

Tried switching to 'normal' audio, and 'mix', via the menu, and 'normal' did eliminate the 'clicking', but ... also sounted 'flat' and monoaural. So this does tend to confirm the problem, I guess.

The model is a JVC HR S3500U, and is (surprisingly) still available. It's features include:

Pro-Cision 19 micron width EP Heads
and
Dual Azimuth - 4 Video Heads + 2 Hi-Fi Audio Heads

The tape is a "Sony Classical" but I can't see any reference to copy protection.

I tried another tape in the unit, paying particular attention to the sound quality, and the sounds was excelent, so ... I guess it's just hard luck with this one tape. Luckily, I just found that Amazon are selling the DVD version now for $13, so that kinda seals the decision - no more time wasted on this one!

Very annoying, though, that this tape - an expensive, and pristine item - would be the one to cause so much trouble!

[dphirschler]

Well you could capture it twice, once with the good audio, and once with the good video. Then trim to the same frames on both videos and save out the good audio to be loaded into the good video. You can capture low res for the good audio to save space. I've had to do that once or twice before. It's a hassle, but it gets it done.


Darryl

[lordsmurf]

Well you could capture it twice, once with the good audio, and once with the good video.

I've done that before. Works fine.

[Bizuser]

Great ideas, and I'll use them in other situations, but ... for this tape, I can't get good audio no matter what I do. I can get audio without 'clicks' etc, by going with the 'normal' (linear) audio, but ... while it doesn't have clicks, it sounds dull, flat, monoaural.

But thanks a lot for the help!

[Bizuser]

Well, I finally dug up the manual for my VCR - that paper thing with staples in it ... (I could not find an online PDF version, what a drag!) and ... found out how to turn off automatic tracking, and how to manually track. Once I figured that out, I was able to track to the point where both the audio and video were good.

Thanks so much for all your help.

For the record, on my JVC, you disable auto tracking by pressing channel up and channel down simultaneously for a brief moment. You then adjust tracking by pressing the up, or down, channel buttons. When you want to return to auto, you press up/down together again. This is not all that obvious - no indicator changes when you do this, so it's not clear you have achieved the mode switch. I just pressed the up button afterwards until the picture went really bad, to 'prove' that I was in manual mode. My strategy was something like this: press 'up' until picture/sound starts to degrade; press down repeatedly, counting the number of presses until it degrades again, then press up again, half the number of previous presses - this roughly puts you 'in the middle' of the tracking range, then up or down a bit if necessary to fine tune.

Anyway, I was able to get a good copy. Thanks again!

UPDATE ...

I also found that turning off 'Video Stabilizer' helped. This is odd, because the manual tells me that video stabilizer only affects EP recordings, not SP recordings. Yet I've found that turning off this feature definitely makes a difference with SP tapes too.

I would like to understand the effect of video stabilizer, video calibration, and tracking - not just what they are (marketing blurb) but also, how they interract. Video calibration is touted as '... similar to tracking, but so much more'. I think video calibration is automaticaly turned off when you go to manual tracking.