Seeking recommendations for video capture card.

sdmcrae wrote on 8/9/2001, 7:56 PM

I have an analog camcorder and need to capture video from it. I am wondering what "DirectShow-compatible" video capture cards folks have tried that they feel work well. Where are the "gotchas" when trying to capture analog video? TIA.

Comments

discdude wrote on 8/9/2001, 10:05 PM

Analog capture is definitely a different beast than digital video captures through a IEEE-1394/Firewire/iLink card (why don't they just choose a name? I'll call it a Firewire card since it the coolest sounding.).

Basically, all a Firewire card does is transfer data from your camcorder to your hard drive. An important thing to note is that the video is already:
(1) Digital.
(2) Compressed (w/ DCT).
when it leaves your camcorder.

On the other hand, your analog video is neither digital nor compressed (digitally). Therefore, an analog capture card must digitize the incoming video and compress it. This requires a lot more hardare. Also, an analog card must have high quality components to minimize noise. That is why good analog capture cards cost a lot more than Firewire cards.

Some cheap analog capture cards (especially TV tuner cards) do not have hardware to compress the video. You CAN use the CPU and a software codec to compress the video, but I recommend that you do not buy these cards if you plan to capture a lot or have a computer that is slower than 1 GHz.

Why does video have to be uncompressed? Consider this:

1 Frame of 640x480 @ 24 bit color takes up: 900 KB
There a 30 frames in a sec so 1 sec of video = 27 MB
Therefore, 1 minute of video takes up about 1.6 GB

First of all, most hard drives are hard pressed to write more than 6 MB/sec.

Second, you are going to need a huge hard disk for all that video.

On the other hand, all DV takes up a scant 3.6 MB per sec.

So, here comes the recommendations:

Analog capture cards typically compress in hardware one of two codecs.

MJPEG: precursor to MPEG. Decent quality but low compression. If you have a fast computer, you can use a cheap TV tuner card and a software MJPEG encoder like PicVideo (http://www.jpg.com) instead.

MPEG2: same compression used in HDTV and DVD's. High quality and relatively high compression. Harder to edit than MJPEG because of interframe compression tho'.

Cost: 300+

Check http://www.pinnaclesys.com and http://www.dazzle.com for capture cards.

Hope this helps.

sdmcrae wrote on 8/10/2001, 7:23 AM

Wow, I had no idea! Thanks for the info, I'll check out those web sites.