From VHS to DVD

[dr3v]

Hi!

Ive bought a DVD-recorder and I want to record my old VHS tapes to DVD. My tapes are recorded as LP, and my recorder has 5 recording options 2 of them are High quality and LP!
My question is: If the the quality on the tape LP, does the quality on the recording get better if I choose High Quality record, rather than LP record?
My question is can the quality get better? :confused:

Thnx
dr3v

[FlimsyFeet]

No, the qulaity will not get better, howver I think it's fair to say that the HQ recording mode on the DVD recorder will give you a more accurate representation of the original tape than the LP mode will.

[dr3v]

Okay thanks! but the thing is that HQ recording will only allow 1 hour recording on each DVD. Which means each tape is convertet to 4 DVDs, which seems weird!
It should be the other way round!?

[rjd0309]

This is a basic question from Information Theory. The issue is that you don't have an unlimited amount of recording media -- your videotape only has just so many feet of tape on it, and your DVD also has a fixed capacity.

Let me see if I can explain it using an analogy. Let's say that you're at a cafeteria, and you want to get a sample of every food item that they have, but you only have one dinner plate.

If you're only recording 2 hours worth of video onto your tape (SP mode), that would equate to only sampling the food at 2 cafeteria steam tables. You'll be able to get a nice big scoop of each food item from those 2 steam tables. After sampling all of the food items, your plate is full.

Okay, now let's suppose that you want to record 4 hours worth of video onto your tape (LP mode) -- twice as much data as before. This would equate to sampling the food at 4 steam tables. But again, you only have the one dinner plate (your tape or disc has a fixed amount of recording space). So in order to get a sample of each food item, and fit all of them onto your plate, you're going to have to take smaller scoops -- half the size as before. This means that to fit 4 hours worth of video onto your tape, you're only going to be able to record half as much picture information from each frame than at SP speed. And with less picture information in each frame, the picture looks fuzzier.

The same thing would occur if you wanted to record 6 hours worth of video onto your tape (ELP mode). Again, in order to fit samples of each food item from 6 steam tables onto your fixed-size plate, you're going to have to take even smaller scoops of each item. This means that in order to fit 6 hours worth of video onto your tape, you're only going to be able to record a third as much picture information from each frame than at SP speed. And with EVEN less picture information in each frame, the picture looks even fuzzier.

So if we try to fit more and more video onto a fixed-size recording medium -- a tape or a DVD -- we have to take smaller scoops of each frame, that is, record less picture data from each frame. So the image quality gets worse and worse.

To get the best quality recording, you should try to completely fill the capacity of your tape or disc. So, for example, if you have 2 hours worth of video that you want to record, set your tape speed to SP, or set your DVD recording option to the 2-hour speed. This means that a 2-hour programme would completely fill up the recording space on your disc.

If, for example, you wanted to record a 2-hour programme onto a disc, but you set your recording speed to "4-hour" mode, then the entire 2-hour recording would fit onto half of your disc (and the other half would be empty). But in order to fit the programme onto only half of the disc, your DVD recorder had to throw away half of the picture information from each frame (take smaller scoops). If you had allowed the recorder to use ALL of the space on the disc, then it could have been able to keep MORE picture data from each frame (larger scoops), and the picture quality would be better.

So when transferring a tape to DVD, the picture quality of your tape is the best you're going to get. If you COULD somehow improve the quality of the picture -- for example, if you could read the label on a pack of cigarettes after you transferred your recording to a DVD, whereas you couldn't read the cigarette label when watching the videotape -- this would imply that the DVD could somehow magically create the image of the cigarette label, when it wasn't there on the tape in the first place. You can't create what wasn't there in the first place. You can't get "Something For Nothing". The Universe doesn't allow that.

(You often see this fallacy in TV cop shows. The police "zoom in" on an image from a security camera videotape, and are magically able to read a car's license plate. In reality, as you zoom in on such an image, you see less and less picture data, so the image just degrades into a fuzzy, blocky mess. Any technically-minded viewer gets a big laugh whenever Hollywood uses this Infinite Zoom Camera trick.)

So the best thing you can do when transferring a tape to a DVD is to set your DVD recorder's speed (recording mode) to match the length of the programme you wish to transfer. So, for example, if you have a 2-hour programme on tape, then set your DVD recorder at the "2-hour" speed. This means that the tape's programme will "fill up" the available space on your disc, and that's as good as it's going to get.

[dr3v]

Thanks a lot for your well compiled analogy rjd0309! :)
I will never forget! (specialy the Hollywood zoom in trick, hillarious)

[2Bdecided]

A lot of contributions in this thread from people who apparently haven't done this!

Getting good playback from VHS isn't that easy. You can certainly get better playback of most tapes by using a decent deck.

The picture can certainly be improved - that's what people use AVIsynth for. denoising, sharpening, colour correction etc.

This is time consuming - unless it's your precious home movies, I wouldn't bother - but some people do!

MPEG encoding doesn't like noise. MPEG encoding in real time is typically lower quality (for a given bitrate) than off-line two-pass encoding.

So if you take your VHS, and record it as-is even in 1-hour mode, it won't be a perfect copy. 2-hour mode is worse, 4-hour mode is worse again. The noisy VHS picture will break up into macroblocks on the lower quality encoding.

Given that you originally recorded in LP mode, I'm guessing high quality isn't your main concern - so yes, you can just fit one tape to one DVD. But the quality will probably be far lower than the painfully slow work process of...

decent VHS VCR > decent capture card > AVIsynth filtering > 2-pass VBR encoding.

Cheers,
David.

[ses]

I'm with Dave on this one, I got marginal results until I was able to buy a JVC S-VHS deck which had TBC as well as some playback filters.
I purchased an ATI Theatrix 550 card and recorded everything straight into the computer with IUVCR and the HUFFYUV codec.
I edited the recordings in AVI format with Virtualdub, used filters where needed, but the most important link in this is just how good quality you have in your VHS playback, and standard VHS in my opinion just won't give you the best possible results.
I have read some disagreement on this, but my experience has been that even LP standard VHS tapes came out better from my S VHS machine than the standard VHS with which I began my project.
Compression to MPEG2 was done via Main Concept and there I recieved the best results setting the Noise Reduction value to 1 from the default value of 12 and I used a constant bit rate of 9000. There is a great deal of debate on the merits of variable bit rate over constant bit rate, but in my experience, I was happier with the constant bit rate result. Using such a high bit rate meant that file over 1 hour in lenght would not fit on a standard 4.7 dvd, so I have all my VHS files on an external harddrive, which works fine for me.
I did not deinterlace and by means of the deinterlacing functíon in the VLS player, the result is fine though one must realize that a VHS recording will never have the quality of a DVD.
Recording VHS to a DVD recorder will give acceptable results, but for the best possible result, it requires the more time consuming work of recording vi a computer, but then again I had lots of time because I broke my foot and could'nt really do much more for those 6 weeks than sit at the computer anyway!