On Wednesday 10 October 2001 21:52, you wrote: > Quoting Eric Pichon <eric@xxxxxxxxxxxx>: > > Each board will have its own camera, either USB or FireWire. > > > > We want to achieve 320x200 at 30 fps and need to use the v4l API. > > > > I would like to know : > > - can we use FireWire cams with v4l ? > > As long as you have the FireWire driver for your camera... > > > - would a USB cam be able to do 320x200x30 ? (because of the USB 12Mb/s > > we would need hardware compression, but will the compression algorithm > > behave OK if the camera is always moving - as on a 25 mph RC car ?) > > USB cam is most likely to be too slow. Existing compression > algorithms (implemented in camera's hardware) are too primitive > for good motion tracking - I doubt even if MPEG would be good > enough for that! > > Even worse: most compression algorithms are trade secrets, and Linux > drivers don't implement them - except Philips driver, which contains > a closed-source optional decompressor. > > A raw, uncompressed datastream won't give you 30 FPS. If you want you > can run two cameras in parallel; but they don't have any means of > synchronization, unfortunately. Otherwise you could run them in > counterphase. > > > If you have any comment - specially about the choice of the cameras > > (should be small, resist to shocks and vibrations and as cheap as > > possible) I'm very interested too ! > > You might need to develop your own camera - which is NOT connected > through USB. bt8xx chips are easy to find, and analog front ends > are also available for $50 or so (the lens, the sensor and some analog > outputs). So depending on what you want you can make a PCI camera. > > If you have a FireWire camera it might work for you. But I haven't > seen any. Here is a FireWire-based desktop video camera http://www.orangemicro.com/ibot.html but I have no clue if there's any way to make it work with v4l Maybe these links will help too http://linux1394.sourceforge.net/ http://www.schirmacher.de/arne/dvgrab/index_e.html > > Dmitri ---------------------------------------- Content-Type: application/pgp-signature; charset="us-ascii"; name="Attachment: 1" Content-Transfer-Encoding: 7bit Content-Description: ----------------------------------------
