vhs to HD DVD "Conversion"

[victoriabears]

I hope not a silly question, but are we alikely to get a better recording quality when HD DVD recorders/burners come out if converting from vhs, rather than , as we are at the moment, from vhs to DVD?

Just a thought.

[guns1inger]

Given the relatively low quality of VHS compared to today's DVD, you are unlikely to get better quality going from one to the other, unless the HD DVD Recoders come with their own VHS playback equipment with built-in proc-amps and TBCs.

[Bob W]

I was thinking one may get a better conversion by running a VHS player output through a video scaler then recording to a HD DVD recorder at 720p assuming thats going to be possible.

[edDV]

well, think about it.

VHS at its best contains about 352x480/576 information per frame. Supported HDTV DVD frames are likely to be 1280x720, 1440x1080 and 1920x1080.

So how to get from one to the other. It isn't going to be pretty.

[edDV]

I was thinking one may get a better conversion by running a VHS player output through a video scaler then recording to a HD DVD recorder at 720p assuming thats going to be possible.

"better conversion" how ?

Think of those sports scoreboards that are 25 Ft tall. They do it with giant pixels.

Go to Photoshop (or similar program) and try to make a 352x480 still into a 1920x1080 enlargement.

PS, by still I mean a VHS frame cap.

[Bob W]

I was thinking one may get a better conversion by running a VHS player output through a video scaler then recording to a HD DVD recorder at 720p assuming thats going to be possible.

"better conversion" how ?

Think of those sports scoreboards that are 25 Ft tall. They do it with giant pixels.

Go to Photoshop (or similar program) and try to make a 352x480 still into a 1920x1080 enlargement.

A video scaler does the conversion automatically. I have one which takes the output from my satellite box and up-converts it to 720p or 1080i and the resulting picture does indeed look a whole lot better.

[edDV]

I was thinking one may get a better conversion by running a VHS player output through a video scaler then recording to a HD DVD recorder at 720p assuming thats going to be possible.

"better conversion" how ?

Think of those sports scoreboards that are 25 Ft tall. They do it with giant pixels.

Go to Photoshop (or similar program) and try to make a 352x480 still into a 1920x1080 enlargement.

A video scaler does the conversion automatically. I have one which takes the output from my satellite box and up-converts it to 720p or 1080i and the resulting picture does indeed look a whole lot better.

better in what way?
how can upscaling increase quality?

are you viewing the original on the same screen?

[guns1inger]

What is the input res froom the satellite box ? I'd be guessing a lot better than old VHS tape.

[Bob W]

What is the input res froom the satellite box ? I'd be guessing a lot better than old VHS tape.

I believe VHS is like 640 x 480 and the output from my satellite is 800 x 600. Anyway the picture displayed on my 43 inch DLP HDTV looks sharper with brighter colors when viewed through the video scaler at 720p. This is the scaler I use.
http://www.bhphotovideo.com/bnh/controller/home?A=details&kw=TVAVT3800&is=REG&Q=&O=pro...ist&sku=306391

[edDV]

VHS is 3MHz luminance + 600KHz chroma equiv to "240 lines of horizontal resolution" in analog terms by 480 scan lines.

Equivalent digital raster is less than 352x480.

Some capture cards need to oversample that size (e.g. 640 or 704) do to limitations of the card. The video resolution is still under 352x480.

Scalers attempt to deal with the "big pixel" problem by using filters that essentially trade bandwidth for edge smoothness aka "antialiasing". To get this to work, you need enough bandwidth in the source relative to display size or the picture goes very soft..

Faroudja DCDi is a good example.
http://www.av-outlet.com/en-us/dept_335.html

[edDV]

I hope not a silly question, but are we alikely to get a better recording quality when HD DVD recorders/burners come out if converting from vhs, rather than , as we are at the moment, from vhs to DVD?

Just a thought.

Back to the original question, there are two ways to approach VHS on HDTV

1. VHS could be captured and encoded the same way it is today with the highest quality 352-720 x 480/576 DVD Mpeg2. These DVDs can be played back on future HD DVD players that will have increasingly sophisticated deinterlacer-scalers for dealing with interlaced video sources of variable quality. Bottom line, today's DVD material will look better with each generation HD DVD player as technology is cost reduced to home budgets.

2. VHS tapes could be recaptured at higher quality and reprocessed with various software and/or hardware image processors before encoding to a HD DVD format (MPeg2, H.264, VC-1 or other).

[vhelp]

I think it *is* possible to give the illusion of a good
upscale, with the proper filter technique, it (VHS) can look good
on larger screen, even with it's limited (shall I say) bandwidth

The problem with VHS, is that most peoples here continue to believ
that it is crappy. And with that attitute, no wonder why it has
stopped be a regular topic. Anyways.

What will make a VHS shine as far as quality goes, is the technique
the particular user incorporates into the resteration process, from
VHS to DVD.. or HD.. or whatever. Anything can be upscalled.
.
@ edDV
.
I'm surprised at your disbelief, because you have helped me to sort
of understand a little bit more..

I was talking about the way video is acquired, edited and presented to the transmission system in a typical TV station..

and then..

* Regardless of upstream wideband digital sources, NTSC is NTSC
so that means it contains a maximum of 4.2 MHz luminance and modulated
chroma C that has at most 600-1000KHz of U and V (aka I and Q) bandwidth.
Unless Y and C are split with a sophisticated comb or notch filter, only
around 3MHz (240lines) of luminance resolution Y is decoded by a typical
capture device. Typical chroma bandwidth is 600KHz per component.

and more.. (but I'll leave it out)

above, were from this original Post:
--> Trying to Understand Capture Card Choices

My belief goes like this.. If you can do it hardware, you can certainly
do it, software. And, with proper technique, even VHS can be upscaled
to a higher resolution for displaying.
.
I'm not sure of the complete machanics (yet, as I'm still learning through
the self-tought methods, many such interesting things) but, I would
assume that one would have to apply the methods across the Y, UV respectively,
and, but *not* just a plain grid of pixles. If Y requires *4* pixles, and
the U and V *1* each, then somehow, the method would be in this path ??
(or, maybe the whole thing would be easier if we just convert YUV to RGB
and upscale that way, and then convert back to YUV. Anyways.
.
I would also go on assuming, that if your source is 411 already, then
you have a chance of obtianing a good upscale.
.
Here's my thoery on how it might be done ...
.
If Y = 4 pixels and U and V = 1 pixel each, then:

[Y] [Y] [Y] [Y]
  [u]     [v]
[Y] [Y] [Y] [Y]

I hope I have my Y[luma] Cb[chroma]/Cr[chroma] pixel placement right, else
please correct me (nicely)
.
If the above layout represents a single pixle area, say of an eye, then..
.
And, giving the above, as one group/count, if we wanted to magnify or upscale
it twice, we would multiply this twice ?? ..or, four times ?? ..for every
group/count of these pixel arrangment
.
Now, imagine the *captured* 720 x 480 grid of this image, and we want to
upscale it to HD size

Regarding the above, repeated below, may be wrong on my part:

[Y] [Y] [Y] [Y]
  [u]     [v]
[Y] [Y] [Y] [Y]

or, would the layout be:

[Y] [Y] [Y] [Y]
  [u] [v] [pad]..
[Y] [Y] [Y] [Y]

The u/v being Cb Cr chroma.

{
if anyone has knowledge on these YUV pixel placement or layout, please
feel free to open up a discussion with me, via pm so that I may be
more educated - is only so much you can learn on the web, w/out proper
pictorial roadmaps
}

-vhelp 3396

[edDV]

.
@ edDV
.
I'm surprised at your disbelief, because you have helped me to sort
of understand a little bit more..

I was talking about the way video is acquired, edited and presented to the transmission system in a typical TV station..

and then..

* Regardless of upstream wideband digital sources, NTSC is NTSC
so that means it contains a maximum of 4.2 MHz luminance and modulated
chroma C that has at most 600-1000KHz of U and V (aka I and Q) bandwidth.
Unless Y and C are split with a sophisticated comb or notch filter, only
around 3MHz (240lines) of luminance resolution Y is decoded by a typical
capture device. Typical chroma bandwidth is 600KHz per component.

and more.. (but I'll leave it out)

A basic law of analog or digital video processing is the higher the quality of the input source, the better the processing result.

Broadcast TV starts with high to very high source quality and uses up some of that quality at each step of the process prior to transmission. The more steps to the process, the higher the original source quality should be. Therefore, studio video cameras, switching-effects equipment and recorders need to exceed transmission requirements. This applies to analog or digital production.

Once it hits the NTSC or PAL transmitter, the signal is bandpassed to NTSC or PAL spec. It may look good but will never better than the bandwidth transmitted.

The same is true with VHS. When you record broadcast NTSC, 4.2MHz luminance will be reduced to 3MHz and chroma reduced to 600KHz. Other serious distortions happen in the VHS recording process that I will ignor for now.

It's like a funnel, but if at each step, the source quality exceeds the process output quality, then the results will be closer to optimal.

VHS to HDTV display is going the other way. You are starting with a bandwidth limited source and trying to add enhancement for display. The tricks that work for broadcasters, like trading bandwidth for edge smoothness, just don't work as well. The picture just wants to go softer and softer as you process. Noise adds to the problem.

So now you need to resort to tricks to fool the eye that the picture is better than it is. The "bag of digital tricks" will improve with research and experience. Known tricks will become more economically feasible for consumer level equipment.

My belief goes like this.. If you can do it hardware, you can certainly
do it, software. And, with proper technique, even VHS can be upscaled
to a higher resolution for displaying.

Any raster can be upscaled. The issue is how it will look and what can be done to make it look better.