On 06/03/2011 06:22 AM, Hans de Goede wrote: > Hi, > > On 06/03/2011 02:15 PM, Mauro Carvalho Chehab wrote: >> Em 03-06-2011 02:40, John McMaster escreveu: >>> I'd like to write a driver for an Anchor Chips (seems to be bought by >>> Cypress) USB camera Linux driver sold as an AmScope MD1800. It seems >>> like this implies I need to write a V4L2 driver. The camera does not >>> seem its currently supported (checked on Fedora 13 / 2.6.34.8) and I >>> did >>> not find any information on it in mailing list archives. Does anyone >>> know or can help me identify if a similar camera might already be >>> supported? >> >> I've no idea. Better to wait for a couple days for developers to >> manifest >> about that, if they're already working on it. >> >>> lsusb gives the following output: >>> >>> Bus 001 Device 111: ID 0547:4d88 Anchor Chips, Inc. >>> >>> I've started reading the "Video for Linux Two API Specification" which >>> seems like a good starting point and will move onto using source >>> code as >>> appropriate. Any help would be appreciated. Thanks! >> >> You'll find other useful information at linuxtv.org wiki page. The >> better >> is to write it as a sub-driver for gspca. The gspca core have already >> all >> that it is needed for cameras. So, you'll need to focus only at the >> device-specific >> stuff. > > I can second that you should definitely use gspca for usb webcam(ish) > device > drivers. As for how to go about this, first of all grep through the > windows drivers > for strings which may hint on the actual bridge chip used, chances are > good > there is an already supported bridge inside the camera. > > If not then make usb dumps, and start reverse engineering ... > > Usually it is enough to replay the windows init sequence to get the > device > to stream over either an bulk or iso endpoint, and then it is time to > figure out what that stream contains (jpeg, raw bayer, some custom > format ???) > > Regards, > > Hans Thanks for the response. I replayed some packets (using libusb) and am able to get something resembling the desired image through its bulk endpoint. So now I just need to figure out how to decode it better, options, etc. I'll post back to the list once I get something moderately stable running and have taken a swing at the kernel driver. John -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
