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View Full Version : Need Advice On Buying A Capture Card


Master Yoda
29th April 2004, 15:40
OK, i installed the latest WDM drivers that are compatible with me geforce 4 ti4200 my vivo edition(got the drivers from nvidias site.But still i cant capture at half res and i cant use the YUY2 colour space.So im gonna invest in a capture card... Now im guessing a tv card and capture card are one in the same.

Now i was looking here http://www.overclockers.co.uk/acatalog/TV_Cards.html and i was looking at the Leadtek Winfast TV2000 XP Expert and the Leadtek Winfast DV 2000 1394 PCI TV Card .Now both use a 10bit video decoder which i guessing is a good thing.But on the leadtek site it does'nt say what resolutions they can capture to or what colour space they capture to.Nether say what chip set they use, but i dont know what chipsets are god or not.

Now are these two cards any good and which is better.Im guessing the second one as it seems to have more inputs.Also does anyone know what resolution they can handle.

Also are any of those other cards any good, or can people name me some cards that are good but not on that site as i can have a look down my local computer fair.

After capturing i will be converting to mpeg2 for dvd.

Last thing is that frame loss ive read about something o do with the card ?

Arachnotron
29th April 2004, 16:18
Both are Conexant CX23881 based cards. The second one also has a firewire chip on board, so if your PC already has firewire I would not bother with it. From the looks of it this is NOT a hardware DV capture device, just a regular TV card with firewire tacked on.

Most cards with these chips can cap YUY2 and have a programmable scaler (so you can choose hor res)


May the force be with you.

Master Yoda
29th April 2004, 22:16
OK im thinking of getting the Leadtek WinFast TV2000 XP Expert as i was reading peoples reviews on it here http://www.videohelp.com/capturecards and nearly all gave it 8+ and i searched google for reviews and they gave it some good ratings.

Now if anyone has this card and can tell me for sure that it can capture using yuy2 colour space and can capture ate half and full dvd resolution that would make me a happy chap as now where seems to say.

One review said Instead of the dated Conexant Fusion 878A the TV 2000 Expert tuner is built on Conexant's latest solution - CX23881 10-bit ADC.
Altough one review said a downside was ' Audio quality problems (no highs)'.Now im not sure if this was the tv tuner of the captured audio.... the same review said 'I personally prefer the image on the Philips 7134 based tuners '.Is the philips 7134 based tuners that much better.... what cards use this chipset...

Lastly i am look ing this card as its only £39.99 on overclockers and it seems like its worth the money(dont wanna spend alot as im not gonna be capturing that much)

DarkNite
30th April 2004, 08:27
Is the philips 7134 based tuners that much better...

Not really.

If you have a good VCR with S-Video out (or S-Video out on your cable reciever) you're a lot better off avoiding the card's tuner completely by using the VCR as your tuner and running the S-Video line to your capture card's S-Video in.

I'm aware that it's not always a practical solution (apparently not everyone has a rec room set up for multimedia editing and serving), but it does yield better results.

I personally haven't done much capturing with consumer level products for a while (aside from helping my nephew with his Leadtek WinFast TV2000 XP Deluxe) so my advice may be outdated with the latest tuners.

By the way, my nephew ended up dumping his LeadTek for a Hauppauge WinTV-dbx(WINTV401) because of some driver issues he experienced, and has been dishing out VHS to DVD conversions steadily since then.

Arachnotron
30th April 2004, 13:26
Is the philips 7134 based tuners that much better...

This is based on a misunderstanding. Neither the CX23881 nor the Philips SAA7134 are tuners. These chips simply accept a video signal and digitize it. This signal can come from an outside video source or from a TV tuner that is soldered on the card, but for the chip this does not make a difference. The confusion probably comes from the fact that Philips also manufacturers most of the tuners used on TV cards.

The only specific TV related function these chips do have is the ability to decode (stereo) sound from the tuners video signal. This is why you often find two versions of these chips - CX23881 and CX23883. Both can process NTSC , SECAM and PAL video, but only the CX23883 can decode the stereo sound encoded in American TV broadcasts.

So, depending on the brand of the card, you will find the CX23881 and SAA7134 teamed with different brands of and different quality tuners. There are probably CX23881 based cards around with Philips tuners on them too.

It has been my experience that TV card tuners are less tolerant for weak antenna signals then the ones in TVset's or VCR's, but provided the antenna signal is good the quality of TV card tuners is equal or sometimes even exceeds what you find in consumer video equipment.

If you have a good VCR with S-Video out (or S-Video out on your cable reciever) you're a lot better off avoiding the card's tuner completely by using the VCR as your tuner and running the S-Video line to your capture card's S-Video in.

This is partly true. TV broadcast is by its nature a composite video source. To digitize it, chroma and luma has to be separated by a combfilter. Both the CX23881 and the SAA7134 incorporate excellent digital comb filters.

Using an external tuner with s-video out only has an advantage if both the tuner is better AND the VCR has the better combfilter of the two.

For example, My JVC HR-S7950 s-VHS deck has excellent playback capabilities, but it's tuner is only passable in quality.

Master Yoda
30th April 2004, 14:00
Thanks for the info, but to be onest im not interested in the tv tuner part of the card, i only want it to capture some vhs tapes to my pc then to dvdr.

just wondered if any knew for sure if the CX23881 10-bit ADC chip can capture at half and full pal res and YUY2

Arachnotron
30th April 2004, 14:11
It can. I have one (Hauppauge WinTV PCI FM) and it does.

For exact aspect ratio, you may have to cap at a slightly lower horizontal resolution and add some black bars to the sides though. The capture window width of most CX cards I have seen is slightly lower then the active window of a DVD.

numlock
2nd May 2004, 22:39
If you capture with CX2388x based cards you need to capture in the the following resolution:

NTSC: 688x480 and then add black bars 16 pixels wide on both sides using AviSynth

PAL: 696x576 and then add black bars 12 pixels wide on both sides using AviSynth

Here is why:
http://www.arachnotron.nl/videocap/site/capture_area2.html

Master Yoda
3rd May 2004, 14:05
OK cheers....

I had a quick skim through but i dint see anything about capturing at half res.So would i apply the same thing to half res.

Arachnotron
3rd May 2004, 14:07
The window width in microseconds stays the same, even at half res. Bbut you cap only one out of two fields.

Incast
13th July 2004, 20:03
Originally posted by numlock
If you capture with CX2388x based cards you need to capture in the the following resolution:

NTSC: 688x480 and then add black bars 16 pixels wide on both sides using AviSynth

PAL: 696x576 and then add black bars 12 pixels wide on both sides using AviSynth

Here is why:
http://www.arachnotron.nl/videocap/site/capture_area2.html


I've done my own calculations for PAL on this and I came to the same result. This leaves me slightly concerned as a CX2388x owner, for the best quality i am going to be left with small black bars 4 pixels wide on the sides of my tv screen (assuming visible resolution is 704x576). Is there any way to avoid this other than capturing at a higher resolution and distorting the image?

DarkNite
13th July 2004, 20:36
It's not likely you'll notice 16 pixels on a television seeing as most television's have a 5% overscan, and upwards of 10% in the worst cases.

For example: I can use AddBorders(26,16,26,16) on one of my televisions, and still wouldn't be able to see the edge of the displayed picture. The other 2 can take 24 pixels before the edge becomes apparent.

Plasma screens and some other HD ready LCD screens may not have such high overscan (if any), but, if you're looking at a tube, then you have soom room to play with.