Bought a webcam yesterday, thought I'd share the experience... I'd given a long list of supported webcam models to my friendly neighbourhood hardware pusher, Amit Kalra. Unfortunately the webcams that seem to work well with Linux (at least according to Google) seem to be pretty high priced -- Rs 4000+. So Amit suggested that I try out the 2 el cheapo webcams has he had lying around in his office, and promptly turned up with them.
One was a Quantum QHM500LM, which reportedly supports up to 4 megapixels with their proprietary drivers. The other was an HP VGA webcam for notebooks. Tried the Quantum webcam first with the gspca drivers. The cam got identified, and device /dev/video1 (video0 is my TV tuner card) created. Unfortunately all apps I tried just gave me a black screen on capture. Switch to the HP cam. That was even worse -- I couldn't find drivers for it at all. Back to Quantum. Being in a fix, I decided to do some R&D. Fiddling about with the Quantum cam, I noticed a small black rubber cap on the lens. With the intuition and logical powers of a Sherlock Holmes, I deduced that this could have been the cause of the black picture. To those of you who have closely studied and applied my methods the next step may be obvious, but let me state it for the record: You webcam will NOT allow you to view anything until you remove the lens cap. Woah! Remove the cap and I actually see some sort of picture in the XawTV screen! Of course, it looks like some sort of ghostly figure right out of a badly-made Ramsay Brothers movie, but WTH, at least it works. Now to fixing the problem. The kernel gspca module has about 20 parameters that control its behaviour. I tried each of them in turn, varying the values to extremes and back to means. Unfortunately nothing worked -- the picture only got messier. Since I wasn't in the mood for trying out all possible combinations of options (at least 20 factorial), I put on my thinking hat and decided, if the first problem (black screen) was physical, why not this one too? Ah, the lens of the camera screws in and out. Oh my $deity, if you screw the lens in, you actually get a clear picture too! Now I can see myself clearly in the XawTV window... I immediately got down to the most important use of a webcam, setting my hair ;) Picture quality is adequate. I get 640x480 with the kernel gspca drivers, which is quite enough for my needs (now I have to figure out a use for the cam), and the cam does some automatic adjustment of exposure depending on what sort of light you are in. Haven't tried any advanced applications (streaming, etc.) with it yet, will report if/when that works. The command I use for viewing: xawtv -n -noxv -device /dev/video1 (or video0 if this is the first capture device). You can also test the cam in mplayer and ekiga. Haven't actually tried a video conference yet, I probably need mode bandwidth for that. To summarise: Camera model: Quantum QHM500LM Driver: Linux gspca (available as a package in the Debian repository) USB: Bus 001 Device 008: ID 0ac8:303b Z-Star Microelectronics Corp. ZC0303 WebCam Kernel messages: /home/user/linux-modules-extra-2.6/debian/build/build_i386_none_686_gspca/gspca_core.c: USB GSPCA camera found.(ZC3XX) /home/user/linux-modules-extra-2.6/debian/build/build_i386_none_686_gspca/gspca_core.c: [spca5xx_probe:4098] Camera type JPEG /home/user/linux-modules-extra-2.6/debian/build/build_i386_none_686_gspca/Vimicro/zc3xx.h: [zc3xx_config:515] Sensor ID:11 /home/user/linux-modules-extra-2.6/debian/build/build_i386_none_686_gspca/Vimicro/zc3xx.h: [zc3xx_config:607] Find Sensor MI0360 /home/user/linux-modules-extra-2.6/debian/build/build_i386_none_686_gspca/gspca_core.c: [spca5xx_getcapability:1215] maxw 640 maxh 480 minw 176 minh 144 Cost: Rs 650 Ease of use: Easy (once you install the driver package and take the lens cap off :) Issues: Video is a bit slow, and lags a bit. Recommended: So far, yes. BTW, note that all webcams reporting USB ID 0ac8:303b aren't the same. Some will work, some may not, so be sure to test your cam before you buy for use with Linux. Feel free to mail any questions you may have to the list. Regards, -- Raju -- Raj Mathur [EMAIL PROTECTED] http://kandalaya.org/ Freedom in Technology & Software || February 2008 || http://freed.in/ GPG: 78D4 FC67 367F 40E2 0DD5 0FEF C968 D0EF CC68 D17F PsyTrance & Chill: http://schizoid.in/ || It is the mind that moves _______________________________________________ ilugd mailinglist -- ilugd@lists.linux-delhi.org http://frodo.hserus.net/mailman/listinfo/ilugd Next Event: http://freed.in - February 22/23, 2008 Archives at: http://news.gmane.org/gmane.user-groups.linux.delhi http://www.mail-archive.com/ilugd@lists.linux-delhi.org/
