Below is an update on working/non-working webcams on Chumby. I'm not sure how useful a "not working" report is since a cam that didn't work for me may work for someone else with different programs or parameters. Note that all the webcams below work under Ubuntu 8.10 using "Cheese". Also, the UVC cams all work with uvccapture under Ubuntu. I thought that was going to be my tip for someone looking to get a webcam for their Cumby However, even that qualification doesn't seem to apply. There is much more variation in UVC than I thought.
Silicon Motion SM371, UVC (090c:b371): works with both ffmpeg and uvccapture (-m ) with resolution up to 800x600.
UVC 1.00 device Sirius USB2.0 Camera (0ac8:3330): Works with both ffmpeg and uvccapture (-m ) Max res. 640x480 (automatically defaults if higher res requested)
USB Web Camera (1c4f:3000) UVC: Errors and no output both uvccapture and ffmpeg
UVC 1.00 device USB2.0 PC CAMERA (18ec:3290) ffmpeg doesn't work, uvccapture crashes (locked up) Chumby.
UVC 1.00 device USB2.0 PC CAMERA (18ec:3288): Errors and no output both uvccapture and ffmpeg.
Phillips IM SN9C105 (vid:pid 0x0471:0x0328) errors and no output both uvccapture and ffmpeg
Vimicro, gspca: (0ac8:301b) uvccapture saves picture but imgtool says "Bogus Huffman table definition" ffmpeg doesn't work
Mi-Pixart, gspca ( 093a:2460), captures data (176x144) with uvccapture without reported errors but jpg file is corrupt. ffmpeg doesn't work.
USING A HUB:
Everything worked as expected with 2 webcams (Sirius and Silicon Motion) plugged into a 4 port hub. Either video0 or video1 could be specified with the "-d" option.
FURTHER THOUGHTS ON WEBCAMS:
As far as I know nobody designs webcams to work under Linux. Philips gets gold stars from bloggers for publishing Linux drivers. From my point of view, that doesn’t help much. Most of my webcams were purchased on Ebay from Hong Kong sellers for less than $10, including shipping. The manufacturer or the hardware ID is never disclosed. The Silicon Motion webcam was a little more expensive ($14.99) because it was advertised as a “10 megapixel” webcam (5 MP actually w/Windows). It’s a very nice webcam, good image quality and good exposure control. Dipping into the mystery bin is cheap entertainment for me. For $5 I feel free to case mod them, change lenses, or pull out the IR cut off filter. The Mi was on sale at Fry’s for $9 before Christmas. It has terrible image quality.