On Wednesday 10 October 2001 22:30, you wrote: > 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 Sorry, wrong link... http://www.unibrain.com/products/ieee-1394/fire-i_camera2.htm this is a much better camera, and the linux1394 pages says it works great. > 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: > ---------------------------------------- > > > > _______________________________________________ > Video4linux-list mailing list > Video4linux-list@xxxxxxxxxx > https://listman.redhat.com/mailman/listinfo/video4linux-list
