I've wanted to record video occationally on my computer for quite a while. A long time ago I had to have Windows installed to be able to use a Rainbow Runner-add on to a Matrox Mystique-card - and later a similar set up only with a Matrox Millennium 2 (I think, I probably still have it somewhere, as it was ex.pen.sive).
It worked reasonably well (when I remember to turn of the screensaver - yes, if the screensaver started (just blanking the screen) some of the software would start encoding weirdly - I think it was RealEncoder).
Well, that was a long time ago and it took some years before I needed to do something like that again.
I searched the net and learned that Hauppauge actually behave quite well in relation to Linux, so I went ahead and bought a reasonably inexpensive and simple card: an ImpactVCB, which has no tuner (which is important to me, as owning a TV-tuner would incur extra expenses in Denmark), bt878-equipped.
With this card I can watch video with xawtv, but recording with mencoder doesn't work properly: It keeps skipping frames constantly. Useless. I've tried turning of APIC (whatever that is, filled my syslog with annoying errors: "kernel: APIC error on CPU0: 40(40)"), turning of ACPI, setting pci=somethingwithirqthatthekernelsuggested - all to no avail. mencoder still skips frames, which makes the recorded video-file useless (looks crap).
I tried cupid once, but it only gave a green picture.
I find it hard to believe that the computer should be too slow - it's a Pentium 4 with 512MB RAM, which is several times more beefy than the ancient Rainbow Runner-setups I had.
I hate it when stuff like this doesn't work.