which resolution to capture old home movies?

[winifreid]

It is almost as if you did not read all the posts to your thread. There many different ideas about capture resolution. Make a test and decide for yourself. Since you have a relatively small HD and slow computer, you may want to consider 352x480 since it will take alot less HD space and processing time will be less if you plan on filtering or doing much editing.

[SatStorm]

Excellent source, top cables: 704 x 480 / 576
Typical mainstream source: 352 x 480 / 576

The difference between 704 vs 352? Unoticable on mainstream screens, slighty noticable on a HDTV (IF the source comes from VHS)

[videopete]

I am performing the exact same task you are: 8mm and Hi8mm to DVD for archiving purposes. I have done many tests.....no visible improvements using 720 res - just more time. Your source is closer to the 352 res. which is what you should be using. Save yourself the time and aggravation, capture at 352x480!!

p.s. See for yourself....capture at 352 and play the DVD and 8mm back from the camera and see....if you notice any difference I'll be surprised because you won't - it will be as close to perfect as you can get.

Encoding has a lot to do with it as well....and will make a large difference in your final product but starting with a 352x480 capture is what you want.

Good luck.

[gshelley61]

SatStorm is right. No difference is visible on a standard direct view CRT television at 352x480. However, there is a visible difference with a 720x480 capture if you have a high resolution display (like a LCD or DLP HDTV, for example).

[zakman]

Thanks to all. I took your advice and did a comparison myself. I could see very little difference on my big old (built in 1979 if you'll believe that!) Zenith TV. However, I could see small differences when I viewed it frame by frame. Capturing at 352 by 480 certainly makes sense, and it seems like that's what most of you who posted suggested.

My next task is to try different bit rates. I am starting with a variable bit rate of 2400-3100 (that seemed to be one of the default choices for 352 X 480). Then I thought I would try doubling it (4800-6100) and halving it (1200-1600) to see if I can tell the difference. Does this sound reasonable?

[SatStorm]

352 x 480/576 @ ~3000kb/s is more than okey IMO. If you filter your source for the things we don't see but the encoders do see, even 2300kb/s is OK

[tigerman8u]

1/2 D1. 352x480

[zakman]

352 x 480/576 @ ~3000kb/s is more than okey IMO. If you filter your source for the things we don't see but the encoders do see, even 2300kb/s is OK

What do you mean by "filter your source"? Sorry for my ignorance.

[non-linear]

In my experience, a 720x480 2-pass VBR video is better than a half D1 video at a fixed bitrate with comparable file sizes. I've captured lots of VHS tapes and notice that half D1 is blurrier, even when viewing it on a 20" CRT television. I can get great results with 720x480 VBR and fit about 3 hours or more on a disc. I like my DVDs to look as close to the original source as possible.

[davideck]

zakman -

Many of these responses are with reference to software encoding.

Since you are doing hardware encoding with your PVR-250, it will take no more time or disc space to capture at 720 x 480 then at 352 x 480 for a given bitrate.

Are you saying that your experiments indicated that 352 looked better than 720? If not, why not capture at 720?

[junkmalle]

It seems to me the point of archiving is to preserve as much of the original as possible. I use a Hauppauge PVR-250 and can see that 720x480 is a little clearer than 352x480 on my 32 inch TV even when capturing from a VHS source.

[zakman]

Since you are doing hardware encoding with your PVR-250, it will take no more time or disc space to capture at 720 x 480 then at 352 x 480 for a given bitrate.

I believe you are correct, that for a given bitrate, the file size is the same, but it was my understanding that if I doubled the resolution (352 -> 720 approx), then to get the same "sensitivity to motion", I need to double the bitrate (since 720 uses about twice as many bits as 352 for an uncompressed frame ). Is this right?

Are you saying that your experiments indicated that 352 looked better than 720? If not, why not capture at 720?

I am saying that I saw some slight improvement when viewing the 720. But I don't know if I want to lose the "Sensitivity to motion" (does anybody have the correct terminology for this?) by keeping the same bitrate. If I increase the bitrate, then I end up with a a bigger file.

[BogieV]

With my limited experience I can say this:

1. Following the theory my first captures were in half D1 format and 4000kbps which I learned later is quite high bit rate - I WAS NOT HAPPY!

2. Changed to full D1 resolution - even at 3500kbps the results are BETTER!

I try to use the full resolution - you can't get later something you already lost at first place. Forget about thta VHS is low resolution - you need to capture everything that'S feeded with the cable!
If you wish later resize but again the DVD player has to upsample to the TV so make you conclusion. I notice the lack of resolution. I also notice that half D1 looks worse even with "sufficient" bitrate.
It is same with stills - capture analog (mean use scanner from small size photo) at low resolution - it will never look good. Scan this tiny picture at the highest resolution your scanner allows - you can do miracles then!

[davideck]

I am saying that I saw some slight improvement when viewing the 720. But I don't know if I want to lose the "Sensitivity to motion" (does anybody have the correct terminology for this?) by keeping the same bitrate. If I increase the bitrate, then I end up with a a bigger file.

Do you notice any artifacts from the "Sensitivity to motion" at 720?
If not, then wouldn't you rather capture the slight improvement?
If so, then which artifact is more objectionable to you?

I find that at 4500 Kb/s (2 hours per DVD), the improvement in detail at 720 outweighs the slight additional motion blockiness. It also seems to me that the increased detail improves the picture all of the time, while the increased motion blockiness is only apparent some of the time.

[edDV]

Thanks all.
So, given that I have a Hauppauge WinTV-PVR-250 capture card, and I am capturing 8mm video, is there any advantage of capturing at 720 by 480, or shall I capture at 352 by 480?

BTW, I am doing this for archiving purposes, so it doesn't matter what DVD player or TV I have today, since I want it to play on future hardware too.

I'm still wondering how a Hauppauge WinTV-PVR handles a 352x480 mode since it's all hardware. Does it capture 720x480 and then filter the MPeg2 encoder to 352x480? That would be my guess.

[SatStorm]

The problem is that cards like winTV PVR 350 & 250, capture and encode at the same framesize.

IF you capture analogue (impossible with PVR 350) at 704 x 576 and encode to 352 x 576, then your result gonna look the same as if you encode to 704 x 576 with the double bitrate.

But those Hauppauge cards capture & encode at 352 x 576/480, so it is natural 352 x 576/480 look less detailed 704 x 576/480. This is not a resolution (framesize) fault / limitation: This is a hardware limitation (If I remember correct, H350 is using a conexant chipset, based on the bt8xxx ones, and those ones are well known for quality issues when you force them to capture at framesizes beyond their native one - I may be wrong on this, others can say if I'm correct or wrong)


To understand what I'm try to say here, you need to download the mainconcept 1.4.2 demo and try the built in capture utility it has. This is the only application that I know that does that. Of course you need a card able to capture at avi format (not the pvr ones)

You can select on which framesize your card gonna capture and on which framesize the encoder gonna encode "realtime". If you set input and output at 352 x 576/480 the result gonna be very blured compared input 720 x 576/480, mpeg 2 output 352 x 576/480.
Try that if you can, so to realise what I'm trying to point to you.

The bottom line is that with those Happauge cards you have better results if you capture full D1.
With the ATI or the rest cards, that use software for capturing / encoding, you may have better results at 352 x 576/480

[junkmalle]

I think the real issue is the resizing/filtering algorithms used by the hardware and software. With software you can have more control than in hardware.

I almost always capture at 720x480 with the PVR-250 with the sharpening and noise reduction filters turned off (you have to use 3rd party software or registry changes to do this). This gives results that most closely resemble the input. I've seen many people here say they crank the sharpening filter up to 7 (max) to make the picture sharper. With a high quality source that results in overly sharp pictures with a lot of overshoot on already sharp edges. It will probably help with VHS captures at 352x480 though.

[zakman]

I almost always capture at 720x480 with the PVR-250 with the sharpening and noise reduction filters turned off (you have to use 3rd party software or registry changes to do this).

Where can I find info on the registry changes?

[junkmalle]

I almost always capture at 720x480 with the PVR-250 with the sharpening and noise reduction filters turned off (you have to use 3rd party software or registry changes to do this).

Where can I find info on the registry changes?

Info:

http://www.cask-of-amontillado.com/htpc.html
http://www.shspvr.com/

Interactive noise filtering program:

http://www.shspvr.com/download/hcwpp2ut.zip

[zakman]

I almost always capture at 720x480 with the PVR-250 with the sharpening and noise reduction filters turned off (you have to use 3rd party software or registry changes to do this).

Another question junkmalle...
You said you have to use 3rd party software or reg changes to turn the filters off? I would have thought they would be off by default and you would need to do something special to turn them on. If they are on by default, any idea when sharpness setting they are set to?

[junkmalle]

I almost always capture at 720x480 with the PVR-250 with the sharpening and noise reduction filters turned off (you have to use 3rd party software or registry changes to do this).

Another question junkmalle...
You said you have to use 3rd party software or reg changes to turn the filters off? I would have thought they would be off by default and you would need to do something special to turn them on. If they are on by default, any idea when sharpness setting they are set to?

I think the default Sharpness setting for the PVR-250 was 2. And the default noise filter setting was 7. I think Hauppauge does this because a lot of people think sharp, low noise video is better. And low noise makes for better compression. I usually capture from digital cable so the picture is sharp and smooth (and often full of macroblocks!) already. The default settings work better for analog sources though.