Capture Card to capture at DVD Res

[LanceSteel]

I recently bought a DVD writer and I am going to convert a bunch of old VHS videos I have to DVD format. Although I have a fast enough computer with enough HD space my capture card seems to have problems capturing at 720x480. I'm using an old STB TV PCI card (BT848). When I capture at that res there are white flashes and other video errors that appear in the captured stream. Anyway, does anyone know of a card that can reliably capture at 720x480? I'm looking for a card that has a tv tuner and can be used with vdub.

Thanks.

[TheInformer]

Lance,

Capturing VHS at that resolution (720x480) is a waste of time; VHS just doesn't have that much information in it. Capturing at 352x480 is a much better idea because you still get the full signal without space/throughput hassles.

I myself have a WinTV PCI card which can capture at 352x480. As for other cards I can't help you there.

[shardison]

First, as far as I know all the consumer level capture cards don't really capture any higher resolution than 640X480. Try 640X480 first and see if you get good results.

I would expect that you would capture at high bit rate, edit, and then re-encode at a lower bit rate. Re-encode with TMPGEnc and a DVD template (resized to 720X480) and you're done. (I use CQ mode, 2000/6000, CQ65 and it averages about 3500kbs/sec for old VHS and looks good)

To answer your question, my ATI AIW-128 captures at 720X480 just fine using MMC 7.6. But I don't. I capture 640X480 and let TMPGEnc do the DVD sizing.

You can also try an encoding or a re-encoding step of using vdub & DivX 4 or 5 and 1 pass "quality based" at 100% quality. DivX drops a lot of noise and low contrast detail in VHS without loosing the high contrast detail. The result is a very clean looking VHS capture. Better than any filters I've tried with vdub. You won't notice what is drops until you compare it with the original. Depends on your taste. Add in a pixel locking filter and your VHS capture will look like it was taped yesterday. It will compress to 2500kbs/second or so with the TMPGEnc CQ setting.

[shardison]

I tend to disagree with the "VHS doesn't need that resolution" to capture idea. Try it both ways, and you will see that higher resolution does improve the quality; especially if you're making DVD's and have the bit rate to suport the resolution.

Look here:

http://www.divx-digest.com/articles/vhs_capture.html

(be prepared to wait a long time for it to load)

[LanceSteel]

Pardon my ignorance but wouldn't capturing at a lower resolution (say 640x480) and then resizing to 720x480 hurt the quality of the end product (or is it unnoticable?)

[shardison]

The answer would be yes, except that consumer capture chips only "see" 640x480. When you tell the capture software to capture at 720x640, it has to re-size each frame from 640x480 to 720x480 on the fly and then encode it. I'd rather let the software spend that time on better capture encoding in it's native resolution. Then I'd hope that TMPGEnc does a better job of re-sizing in it's own time. Personally, I can't tell the difference if I let the card software do the re-sizing or if I do it in TMPGEnc.

[TheInformer]

To quote from Luke's Video Guide:

"Does capturing in a higher horizontal resolution (e.g. 640 x 240) and resizing to your desired resolution (e.g. 320 x 240) produce a video that has a higher quality than a video captured directly at your desired horizontal resolution (e.g. 320 x 240)?"

Usually, the answer is no. Unlike capturing in a higher vertical resolution, capturing in a higher horizontal resolution generally has little to no effect on video quality for most capture cards.
...
Horizontal Resolution of a Source Video
In the horizontal direction (from left to right), an analog video signal is not divided into a definite number of lines or pixels. Instead, the image is purely analog. This means that it cannot be broken up into a certain number of pixels that would contain all the detail in the original signal. However, we can approximate the detail by taking numerous snapshots of the source image at closely spaced intervals. This is exactly what your capture cards does. It looks at the source video and takes snapshots, called samples, of the image at closely spaced intervals. When it comes time for the capture card to pass the video along to the rest of your computer, it blends these snapshots together to create an image that meets your desired horizontal resolution (e.g. 640 pixels). Essentially, the capture card is capturing the video at a really high horizontal resolution and then resizing it for you in hardware.

Most capture cards follow this same procedure no matter what horizontal resolution you specify. Therefore, an image captured at 640 horizontal pixels and an image captured at 320 horizontal pixels will both be captured internally by your capture card at a high resolution. The only difference lies in how much the capture card resizes the video. If you capture in a high horizontal resolution and then resize the video through software, you are usually wasting your time. Since the capture card will do the resizing for you, it is generally pointless to capture in a higher horizontal resolution than you want your final video to be. You won't gain any additional detail because the capture card internally captures the image at a high horizontal resolution, no matter what resolution you pick.

Of course, if your capture card doesn't do a good job of sampling or resizing the video, then you may get better quality by capturing in a higher horizontal resolution and resizing. However, I believe that capture cards like that are in the minority.

http://www.geocities.com/lukesvideo/highvslow.html

Leopold has a nice little page set up with the cold hard numbers, the numbers dealing with resolutions of the various video formats. You might want to stroll on by http://www.cs.tut.fi/~leopold/Ld/VideoFormats.html and give it a look.

I stick to my previous statement in that capturing at 352x480 captures the VHS signal wholely.

[nemethmik]

I tend to disagree with the "VHS doesn't need that resolution" to capture idea. Try it both ways, and you will see that higher resolution does improve the quality; especially if you're making DVD's and have the bit rate to suport the resolution.
http://www.divx-digest.com/articles/vhs_capture.html

Shardison, you are absolutely right. Yesterday I captured video from a VHS casette in both VCD and DVD resolution using MyDVD, and I found the DVD capture much better, although, consuming much more space.
Thanks for the background info; now I understand why is this.

[Fred©]

To answer your question, my ATI AIW-128 captures at 720X480 just fine using MMC 7.6. But I don't. I capture 640X480 and let TMPGEnc do the DVD sizing.

I have an ATI 128 Pro on a Duron 900 MHZ, 512 MB PC133, HD 40 ATA100, win98 and win2k installed, ASUS A7A133 Mobo... Can you capture over 1,50 Mbits or more? I cannot capture anything over 1,5 Mbits ? can you help me tuning my system?
Fred©

[shardison]

Informer: Yes, 352 x 480 probably does get all of VHS information. But on my ATI card, I can see the difference, expecially after I have to stretch it out to 720 for DVD. Perhaps this is due to lower quality hardware re-sizing in the ATI card. I capture at 640x480 and it's sharper than 353x480.

nemethmik: vcd resolution throws out half the vertical interlaced information. So the DVD capture is going to look a lot better as it retains all 480 lines. I was saying to Informer that 640 horizontal looked better than 352 horz in capturing. I should be wrong, but on my ATI card 640 looks better.

Fred: Get the 7.5 or 7.6 MMC and leave the template settings alone. Only increase or decrease the bit rates. Still sounds like you have a problem... you should be capturing whatever you want. Try I frames only or less b & p frame combinations.[/b]

[YngwieJM]

Back to the original question...I have the Visiontek Xtasy Everything (GeF2 MX 400) and it captures great using v-dub at 720x480. I have not used the tv tuner functions as I don't have a satelite feed in my basement yet. As far as the arguement goes with what rez to use- if you have the hard drive space and are not dropping frames when you cap then go for 720x480. If you just want to capture (arguably) vcd quality then use the WINDVR software that comes with the card for realtime mpeg compression.

[vhelp]

fred,

yeah, but HOW were you comparing it???
A * were you viewing on your PC monitor??
B * or, were you viewing an ENCoded vcd/svcd on your TV???
If A, then this technique is not valid. Its ASSumed that the end
goal is a VCD or SVCD, and NOT pc viewing. Capturing a vhs source
in a hgher res. ie, 720x480 will obviously give you better quality
ON YOUR PC monitor, but, NOT on your TV set after encoding to VCD
or SVCD. In the end, you've waisted:
* space
* time
* encoding (filters, etc) and other such headackes cause you
capped at such a meaningless high res.

As TheInformer said/recommended, and I recommend as well,
and as always for vhs, cap on at 352x480 for vhs source materials.
* much less capture file space
* and encodes are quicker remember to encode to VCD, cause quite
frankly, svcd will ultimately look the same as VCD. Only difference
in teling of quality if the METHOD/PROCESS you used in your final
enocde to VCD, ie frameserving/filtering, etc.

However, if you're planning on watching on your PC monitor, then the
other way is better (to a point) that is, capping your vhs source
in higher res. 720x480 for example. But, still is a waist of time,
being that the quality really sucks anyways for vhs, he, he....

And, before you go their, NO, NO, NO, DV caming it will NOT make
your vhs captures better qality!! Please do NOT believe what others
are saying less you pay strick attention to what they are saying.
cause they are NOT saying what you're thinking they R saying, got it?
There's NO difference in capping analog at 720x480 w/ NO frame drop
vs. DV cap via firewire w/ NO frame drops. In fact, I'd go with the
analog being the better quality (due to NO color loss) while the DV
capure has a color issue

And, may I add, that nothing beats a good AVI capture vs. an realtime
MPEG1 or MPEG2 capture/encoding on the fly. After a while, you'll
soon opt for better quality, cause in the long run, you'll sooner
or later begin to notice gliches or artifacts in those so called
real-time capturing to MPEG1/2.
Lance, trust me, you wont want the real-time MPEG caping - sooner
or later. You will opt for the AVI loooong encoding process but
worth every minute or hour spent on it for maximum quality, period!
No hold bar! Believe me, I've done it, ben there already.
Those R my facts, BOME!!

I'm just giving you the facts based on MY experience.

-vhelp

[LanceSteel]

Thanks guys for all your help. I think I understand what to do. I guess I can either capture at 352x480 or 640x480 and resize to 720x480. shardison, I tried a pixel lock filter in vdub and you are right it does make the quality better.

Since everyone's been so helpful maybe you can help me with another problem thats been plagueing me for awhile. When I try to capture certain VHS's (usually older ones but happens with newer tapes too) I get a rainbow effect at the top of the screen. Now this is not visible when playing from the
VCR->TV but it shows up when capping from VCR->Capture Card. If I fiddle with the input cable (switch from SVideo to composite) the problem is diminished slightly. Does anyone know what causes this or how to fix it? Is it a crappy input connection or something with the original recording of the program?

Here are two samples of what I'm talking about:

http://platinum.chemistry.montana.edu/~banderson/images/one.bmp
http://platinum.chemistry.montana.edu/~banderson/images/two.bmp

Thanks for all the help.

[Anonymous65]

To capture VHS video tape, follow some simple steps.

- capture both fields (x480/x576)
- capture at least 352 horizonal pixels (640 is also fine, but not needed)
- do NOT deinterlace. DVD video is interlaced, so is VHS video.
- 352x480 @ 4Mb/sec looks better than 720x480 @ 4mb/sec when the source is VHS. (no motion artifacts and edge noise with lower resolutions while using the same bit rate)

[Fred©]

When I try to capture certain VHS's (usually older ones but happens with newer tapes too) I get a rainbow effect at the top of the screen. Now this is not visible when playing from the
VCR->TV but it shows up when capping from VCR->Capture Card. If I fiddle with the input cable (switch from SVideo to composite) the problem is diminished slightly.

Well, your tape has lost colour, because some fungus or your VCR heads must be cleaned or changed... or maybe the image was captured as NTSC when the source was PAL or vice-versa.these cases, I got the same BLUE, PINK, GREEN, GRAY coloured images...

Fred©