Capturing VHS at 720x480 is overkill?

[MrMungus]

True or false? I keep reading about people doing captures at half that size because VHS is only X number of lines, etc. Would I get the same quality from a VHS capture at half the size I'm capturing now?

[Tommyknocker]

It is my understanding that it will not increase the quality. But only you can decide for yourself by capturing a sample at each resolution. I also suggest you choose a scene with a lot of action to be certain.

[Gazorgan]

A good question. Strictly speaking VHS is analog, not digital. That means it's a little harder to quantify what it's resolution is. The math is a little deep but empirically it's nowhere near DVD quality. It's actually pretty much VCD quality. Now VCD is 352x240 progressive. 1/2D1 is 352x480 interlaced. I won't call them the same thing, but the horizontal resolution is the same. That resolution is above what a VHS tape can mathematically spit back out.

Now SVCD's always look better than VHS. To me 1/2D1 always looks better than VHS (I have some DVD's and VHS tapes of the same movie). I've actually flipped between both running at the same time on the same TV (AUX input 1 and 2). Even a well done VCD can look better than tape, but the artifacting is more noticeable(as is background crawling). The real test is after the tape has been viewed 30-50 times (how many of us buy used tapes for 1/2 price?), then it's incredibly noticeable!

Basically 1/2D1 is great resolution for VHS tapes.

[xtreemkareem]

I'm with Gazorgan on this one.

[triphop]

720x480 is overkill for VHS. VHS has really only 230 vertical lines, so Gazorgan is correct - 1/2D1 is good enough. And while it is analog, there is still a scanline which means there is still a vertical resolution - horizontally, the story is different - there you are limited by the slew rate of the amplifiers and the bandwidth of the signal...

[indolikaa]

There are people who claim they can see a difference between Full-D1 and Half-D1 from a VHS source. My eyesight is poor enough that I would not even bother to argue the point, since I can't see the difference myself.

But given the analog 'composition' of the VHS signal, you'd have a hard time convincing me that Full-D1 would ever be justified.

[Will Hay]

For me, 352 x 576 (PAL) at 4000CBR is more than sufficient.
Will Filter

[indolikaa]

For me, 352 x 576 (PAL) at 4000CBR is more than sufficient.

What's the lowest bitrate you've tried where you still got (in your opinion) a good transfser?

[Gazorgan]

I've done 2000 CQ on 1/2 D1 and had acceptable results (animation, slow movies). I typically shoot for 3000 CQ (action), which is probably double the typical SVCD bitrate (resolution versus bitrates adjusted).

[indolikaa]

Interesting...

I did a VBR 0-2500-5000 on a 20-year-old EP recording last night and I can't see a difference between them. We played it on a 32" Sony TV and, well, it looked better than the VHS tape, so the end-user was pretty happy.

[andkiich]

Best thing to do in this situation, read this:

www.lordsmurf.com

[MrMungus]

Best thing to do in this situation, read this:

www.lordsmurf.com

Well, the problem there (and in this thread) is that "good enough" for one person might not be "good enough" for another. I'm wondering if capturing at half-D1 is exactly comparable to capturing at full D1. Is there a quantifiable difference or not?

[FulciLives]

I've noticed that if you capture at Full D1 and encode to DVD spec MPEG-2 at Full D1 that it can look slightly sharper than if you did the final MPEG-2 at Half D1.

However at Half D1 you need less bitrate to look good so unless you use a full frame TBC (especially from a VHS source) then Half D1 will look better in that you won't have any compression aritfacts.

I'm happy with Half D1 but I suspect that on a very large TV (say 50" or bigger) or a TV with extreme clearity (such as a large PLASMA) that the difference might start to be noticeable.

It's not that Half D1 is too low for VHS sources it's the fact that the image gets stretched out from 352 to 704 that causes that "soft" look.

I still use it (even for most LD transfers) but I don't have anything bigger than a normal interlaced 27" TV

- John "FulciLives" Coleman

[rhegedus]

This thread might be old, but the information is rock solid:

https://www.videohelp.com/forum/viewtopic.php?t=127563

[SaSi]

For PAL VHS, recording at 720x576 and encoding at 7000kbps average gives me the same overall picture quality compared with half D1 and 3500kps encoding. (I chose relativelly high bitrates to verify resolution rather than MPEG encoder capability).

For VHS, if it's SP I capture and encode at half D1. If it's LP or EP I capture and encode at 352x288.

However, capturing a high quality TV transmission at half D1 smears the picture visibly, even looking at the original hyfyuv encoded AVI.

If you want to fit more content on a disk, it's better to cut the frame in half (by width) rather than just drop the bitrate.

However, even for VHS (SP), cutting the lines in half as well visibly destroys the picture quality.

All are according to my eyes and my 19" PC screen or my 21" TV screen.

[Will Hay]

Hey

For me, 352 x 576 (PAL) at 4000CBR is more than sufficient.

What's the lowest bitrate you've tried where you still got (in your opinion) a good transfser?

I only tend to drop to 3000CBR, the things I do are circa. 20 mins each and I fit six on each DVDr.
All thanks in part to reghedus and his constant bleating about this great thread here
Will

[pijetro]

Since encoding time is an issue for me, i prefer capping and encoding at 352x480..It goes a lot fasther than 720x480. As far as the picture quality goes, I could never tell a substantial difference. Especially since the output is for television...
I believe that a 720x480 capture might also introduce more noise, but this is purely speculation...

Another advantage of HalfD1, is the fact that you can fit lots more playback on a disk, since the bitrate doesn't have to be as high as the FullD1 to keep the same quality....

Good luck!!!!

[rhegedus]

All thanks in part to reghedus and his constant bleating about this great thread here

I just can't recommend it enough - it should be a sticky!

[qlizard]

It's not that Half D1 is too low for VHS sources it's the fact that the image gets stretched out from 352 to 704 that causes that "soft" look.

Fulicilives, I believe you have a JVC SVCR. Do you think that the above would warrant using the "sharp" setting while capturing in 1/2 D1 from the VCR? I'm going to test it tonight to see if it helps the resulting product look less "soft".

[Nelson37]

The factor many fail to consider is that it is NOT what the supposed resolution of the source is, it is what your capture card does at particular resolutions.

I absolutely agree that the theoretical evidence is clear that a resolution of 352x480 SHOULD be enough to accurately represent the video on a VHS tape.

BUT - we cannot magically, perfectly transfer that tape to digital. We must use a capture card which may introduce smoothing filters, or poor quality resizing algorithms, or some other unknown factor. I live in the real world, not friggin' theory land.

I have repeatedly tested various capture resolutions, and it is extremely clear that all three of my ATI cards gave lesser quality at 352x480 than at either 480x480 or 720x480, from a VHS source. While it is hard to see significant difference from 480 to 720, the step from 352 to 480 is clear, even dramatic. Since I cap MPEG-2 for DVD, and 352 just won't cut it, 480 is not valid, and 704x480 is not available in my MMC, 720x480 is the best choice. BECAUSE IT LOOKS BETTER, THEORY BE DAMNED.

I suggest you try several tests and decide what looks best. If you just want someone else to tell you how to do it, while you're at it why don't you let them pick out your clothes, your car, what color to paint your house, and how much ketchup (or even mayonaise) to put on your french fries.

[FulciLives]

It's not that Half D1 is too low for VHS sources it's the fact that the image gets stretched out from 352 to 704 that causes that "soft" look.

Fulicilives, I believe you have a JVC SVCR. Do you think that the above would warrant using the "sharp" setting while capturing in 1/2 D1 from the VCR? I'm going to test it tonight to see if it helps the resulting product look less "soft".

My JVC S-VHS broke down on me a good 6 months or so ago.

Mine wasn't a very high end model (it was the HR-S5900U model) but it did have the settings you are talking about.

I've done most of my capturing using an old 6-head Toshiba VHS VCR that always gave me better quality than the JVC S-VHS unless I was recording a high quality source in S-VHS mode (the Toshiba is VHS only).

I never much used the JVC S-VHS for capturing since my Toshiba gave a better picture with VHS sources.

According to the JVC S-VHS manual you should set the picture to EDIT when you use the JVC S-VHS as the playback source for something you will be recording.

- John "FulciLives" Coleman

P.S.
Ask smurfy since he has more than one JVC S-VHS units

[sacajaweeda]

I usually cap VHS at 368x480.

[Will Hay]

All thanks in part to reghedus and his constant bleating about this great thread here

I just can't recommend it enough - it should be a sticky!

You're right, it should

Ask smurfy since he has more than one JVC S-VHS units

He has, he's so many I heard he put six together and formed a dining table
Will

[johns0]

I found capturing vhs at 640x480 and then encoding at 352x480 gave me a noticeable improvement than when i tried the same capture at 352x480 and encoding at 352x480.

[Will Hay]

I found capturing vhs at 640x480 and then encoding at 352x480 gave me a noticeable improvement than when i tried the same capture at 352x480 and encoding at 352x480.

Yeah, that's a good point.
I have the ADVC-100 so all mine are 720 x 576 from source, but I encode at 352 x 576.
Will

[MrMungus]

I've done most of my capturing using an old 6-head Toshiba VHS VCR that always gave me better quality than the JVC S-VHS unless I was recording a high quality source in S-VHS mode (the Toshiba is VHS only).

I never much used the JVC S-VHS for capturing since my Toshiba gave a better picture with VHS sources.

I noticed this, too. I have a Toshiba and the image was sharper on it than my JVC. But I wanted s-video input and TBC and I noticed that some sources will "smear" using the composite input...

[pijetro]

johns0 wrote:

I found capturing vhs at 640x480 and then encoding at 352x480 gave me a noticeable improvement than when i tried the same capture at 352x480 and encoding at 352x480.

Hey, I've always wanted to try that out...If I'm using AVISynth, would you suggest BillinearResize, BicubicResize, or LanczosResize ???

Thanx...

[FulciLives]

johns0 wrote:

I found capturing vhs at 640x480 and then encoding at 352x480 gave me a noticeable improvement than when i tried the same capture at 352x480 and encoding at 352x480.

Hey, I've always wanted to try that out...If I'm using AVISynth, would you suggest BillinearResize, BicubicResize, or LanczosResize ???

Thanx...

For size reduction you should use BicubicResize or LanczosResize. Personally I prefer LanczosResize as it is tends to produce a sharper image.

- John "FulciLives" Coleman