Implications of using many USB web cameras

Question

I\'m looking into connecting multiple low resolution USB webcams to a single computer. What implications might this have on performance? How does, for example, four 320x240

Answer 1

Wrong.

First, USB 2.0 is 480mbps theoretical, and you should be able to get up to about 80% of that with a direct connection.

Second, to calculate the bandwidth used by a camera, image bit depth must be taken into account, therefore: BW = hresolution() * vresolution() * imagebitdepth(bit) * framerate(frame/s) (in bit/sec) imagebitdepth can be, for webcams, 8, 16, 24, or 32 bits (ranging from Y800 monochrome to RGBA/RGBT colour full, check spec)

Therefore, a typical webcam @ 640*480 resolution, 30fps, 16bit RGB bit-masked RGBA image bit depth will require 147.456 Mbps, and consequently, one of similar spec but @ 320*240 resolution would require 36.864 Mbps, as opposed to the major BS stated by Shawn above with his 1mbps which then is also inconsistent with just about all of his other, also wrong data.

Simulatenous operation is nevertheless largely driver dependent, it is up to the manufacturer to take the otherwise minimal effort and expose unique device IDs to DirectShow.