VHS to DVD - concerning resolution

[sirhc]

When copying from VHS to DVD, how do I maximize the quality of the recording? I learned that the horizontal resolution of VHS is 240 lines and DVD is 540 lines. Does this mean that it is impossible to lose quality when converting VHS to DVD? Similarly, would it be pointless to use the highest quality setting of the converter?

[Chewy]

welcome to the forum

vhs is analog based, dvd digital

if you copy one vhs to another, there is significant degradation, make a copy of a copy and then it's hardly usable

if everything is working right a dvd made from a good vhs would be almost as good as the vhs

"garbage in, garbage out"

[sirhc]

welcome to the forum

if everything is working right a dvd made from a good vhs would be almost as good as the vhs

Would I see a difference between the following two DVDs?

1. 1 hour of VHS (SP quality) on 300 MB

2. 1 hour of VHS (SP quality) on 3 GB

Thank you.

[Chewy]

I would put about 3 hours or less of vhs on each single layer dvd just to be safe

[olyteddy]

A lot depends on your source. Badly lit hand held home made VHS needs a much higher bitrate than good clean steady HollyWood produced footage. In other words, noise doesn't compress well. Blank DVDs are pretty cheap so if it's home made stuff you're recording I'd go 90 minutes (or less) to a DVD.

[RFBurns]

There really isnt any way to get increased quality from VHS onto a DVD. The VHS should be as clean as possible for a decent transfer to any digital medium.

Some stand alone DVD recorders do have circuitry that cleans up some noise and other junk in analog video sources. But as Chewy stated earlier...junk in junk out.

With 240 lines going into the DVD recorder, your gonna get 240 lines onto the DVD disc..period. Without the use of a very expensive line doubler encoder, which just doubles the scan lines of every other field, you still end up with less than pure DVD quality.

The s/n ratio also contributes to dubbing quality. Analog VHS, even the hi-fi units using the top notch quality blank tape, had a very poor s/n ratio even in SP mode. This noise is also transfered to your DVD copy.

Any analog source is gonna have some noise level to it which gets copied along with what you want to copy. There are filtering devices that can reduce this noise floor somewhat, usually with brick-wall filtering techniques and A/D-D/A conversion and resampling. Other than that there really isnt much you can do to purify a 240 line VHS signal.

[rago88]

Bottom line as Chew said,
;Garbage in, garbage out so even with some noise reduction, your spoiled with digital, dvd, etc..

I import alot of analog vhs, super vhs stuff and in the end no matter what I do,
still looks analog video..
but,
I must say, my old camcorder 8mm tapes from 15-17 yrs ago look as good as they did the day I filmed and on tv or monitor PLAYBACK looks sharp as hell but, after tranfered to dvd?
not as good..

[ulTRAX]

When copying from VHS to DVD, how do I maximize the quality of the recording? I learned that the horizontal resolution of VHS is 240 lines and DVD is 540 lines. Does this mean that it is impossible to lose quality when converting VHS to DVD? Similarly, would it be pointless to use the highest quality setting of the converter?

I never understood stood the old way of measuring horizintal luminance resolution. It was not across the full screen but 3/4 of the way across. So to convert the old method into "full screen", one I think makes more sense, if I remember correctly VHS was approx 320 lines, NTSC broadcast 440, Hi8 500, and DVD is 720.

Are you going to burn on a PC or stand alone DVD recorder?

I'm use to using some of the tools once discussed here that took a long time to process but permitted optimal compression. DVD recording on the fly... especially at the 4 hour mode, introduces unacceptable artifacts. They are less noticable at the 2hr speed but still there.

For recording I would oversample at the highest bitrate you can but not below the 2 hour mode. I don't know what your source tapes are like but does your recorder have VBR? My Panasonic has it so I can record a 90 minute show using the entire disk instead of in 2 hour mode and wasting some of the disk.

But rago is right... don't expect miracles. Remember that the only video format worst than VHS was Fischer Price.... that is unless there's some intermediate Yugo format. LOL

[sirhc]

To sum up what I am hearing:

It is possible to lose quality when going from VHS to DVD because, as stated by olyteddy, "noise doesn't compress well."

I will now try out different quality settings to see the effects.

[ulTRAX]

To sum up what I am hearing:

It is possible to lose quality when going from VHS to DVD because, as stated by olyteddy, "noise doesn't compress well."

I will now try out different quality settings to see the effects.

I can only add that you may be better off NOT running the VHS video through any luminance or chroma DNR because it may apprear to improve the source signal, but you can't get rid of it once it's recorded. I expect most DVD players have options to use DNR in playback anyway. I still remember when I first bought my first VCR back in the early 80's and wanted to make copies of various things. I bought a video enhancer thinking it would improve the quality. Well it looked better on the screen but that's not the way it recorded. I could have always sharpened the signal afterward... but doing so before ruined the picture.

Does your playback machine have a Time Base Corrector? I know digital video has it built in, but I'm not sure if it can apply it to the incoming analog signal that may have some timing issues.

[sirhc]

A quick search resulted in only a few sites mentioning Time Base Correction on my machine, Panasonic DMR-EZ47VK. They said that it indeed has the function. The sites are unofficial, though.

I compared 4 quality settings (1-, 2-, 4-, and 8-hour modes) in converting from VHS to DVD with the original VHS. The study was non-blind. Results:

• 1- and 2-hr modes looked the same. I couldn't distinguish them from VHS.
• 4-hr mode noticeably dropped the quality.
• 8-hr mode dropped the quality even more. It was very noticeable.

Many have stated in forums that they prefer recording below the 1.5-hr mode. Therefore, I will re-investigate whether 1- and 2-hr modes are noticeably different.

If it is, I will return my machine for one that has Flexible Recording in VHS-to-DVD dubbing.

[ulTRAX]

A quick search resulted in only a few sites mentioning Time Base Correction on my machine, Panasonic DMR-EZ47VK. They said that it indeed has the function. The sites are unofficial, though.

Like I said it's standard in digital video... but then why mention it unless it's for the analog video? TBC was once a big deal in prosumer equipment back in the mid-90's but it should be easy to include these days.

I compared 4 quality settings (1-, 2-, 4-, and 8-hour modes) in converting from VHS to DVD with the original VHS. The study was non-blind. Results:[LIST][*]1- and 2-hr modes looked the same. I couldn't distinguish them from VHS.[*]4-hr mode noticeably dropped the quality.

I was not impressed with Panasonic's Diga. It promised full resolution in the LP 4 hour mode but they didn't mention it was at the cost of excessive compression loaded with artifacts.

If it is, I will return my machine for one that has Flexible Recording in VHS-to-DVD dubbing.

My Panasonic has VBR "flex recording". It's a great feature. Yours doesn't have it? It seems you're stuck between wanting the best transfer from analog which in my opinion requires TBC... and getting optimal bitrates on the DVDs. I would not exchange TBC for VBR. I'd just record at higher bitrates and end up with extra disks. Of course I don't know what source video you want to transfer.

[sirhc]

My Panasonic has VBR "flex recording". It's a great feature. Yours doesn't have it?

Mine has it, but it can only be applied to Timed Recording, not to VHS-to-DVD dubbing.

[ulTRAX]

If your box is like mine then the Nav structure is not very well thought out. You might also be able to access FR through FUNCTIONS > OTHER FUNCTIONS. I used it for some trials converting old Hi8 tapes from my editing deck to DVD. You can set the FR time there and just hit start to begin recording... that is if it's available on your box.

[RFBurns]

I never understood stood the old way of measuring horizintal luminance resolution. It was not across the full screen but 3/4 of the way across. So to convert the old method into "full screen", one I think makes more sense, if I remember correctly VHS was approx 320 lines, NTSC broadcast 440, Hi8 500, and DVD is 720.

Where did you get these specs from? (rfb is an NAB/SBE/FCC licensed broadcast engineer)

But rago is right... don't expect miracles. Remember that the only video format worst than VHS was Fischer Price.... that is unless there's some intermediate Yugo format. LOL

Actually the worst format to be put out there in the consumer market was 1/4" C open reel format. This may be a bit before your time but was the only thing around them days. It sported 170 lines H res and no color. Ran at 7 1/2 ips on 7 inch reels.

The worst format in the professional arena was the old bulky 3/4 format. It barely stood above standard VHS. The old 3/4 format had 240 lines H res.

The only thing a TBC is going to give you is stable sync pulses and color burst frequency. It may give you some adjustment control over brightness, luminance and chorma saturation and color phasing (hue or tint control), other than that it wont clean up the already low grade VHS video signal at all.

I would be carefull tho...playing around with them old tapes trying to get blood out of a turnip will only put more wear and signal degridation off the tapes. Each time you run those magnetic tapes across a head, it degrades the magnetic particles even further.

I would just dub them over to a DVD now and then after they are on a more workable format, play around with squeezing the blood from that turnip.