Video artifacts and their cause?

[Shamus]

So me and a friend were filming some video. The camera doesn't have a digital out, so to capture it we have to run it through a yellow-white-red cable (I don't know the technical term for it) to another camera that has a firewire out, then to the computer. It was captured as an uncompressed avi. When I got home, I started editing and noticed these line type of artifacts around things that move. This picture was taken from an flm file (Filmstrip) that was saved straight from the avi, so there shouldn't be any degradation other than this pic being saved as a jpeg.

http://www.speakeasy.org/~halcyon/jaggies.jpg

It amplifies them even more after rendering :(

PS I just assumed that an flm file is basically saved like a bitmap with no compression, am I right?

[zubaz]

It's called aliasing - the sample rates aren't matching up. But despite knowing what it's called, I have no idea how to fix it.

[Threeboy]

i thought it was interlacing.

artifacts are also caused by noise and interference, and the big one: compression!

[Shamus]

Well I talked to a friend that knows a lot about video and he said it's normal; unless you buy a $2000 camera that has 'frame mode.' :(

[Serious Sam]

I think you may be going from analog to digital?

[Threeboy]

Well I talked to a friend that knows a lot about video and he said it's normal; unless you buy a $2000 camera that has 'frame mode.' :(
*puts it on shopping list*

[Shamus]

The camera doesn't have a digital out, so to capture it we have to run it through a yellow-white-red cable (I don't know the technical term for it) to another camera that has a firewire out, then to the computer.
I think you may be going from analog to digital?
In short, yes. Do you think it is adding to the problem?

[brentech]

The technical term is just RCA cables. Yellow = video, red and white are both audio.
If you had a digital camera, it would be much better quality. Going from analog to digital means that the card receiving the data on your computer has to recode that data to make it digital. So if the sampling rate is too low, then you're going to get stuff like that. I don't know if it's the same for video, but the standard for audio is that your digital sampling rate should be at least double that of the actual analog recording.
That way it produces a crisp image.

[Serious Sam]

Or simplified, analog to digital never works. Uncompressed avi won't help either. Go all digital.

[SileNceR]

going from NTSC to PAL or vice versa can cause similar effects, trying to add or remove frames (ie add every 3rd frame to every 4th to drop 1 out of 3 frames, not that extreme tho)

or combine every 3rd and 4th to make a 3.5th frame and make the 4th frame no. 5.

[rocket.]

A friend transfered video of an analogue camera using a capture card, It works fine.