falco.hirschenberger at itwm.fraunhofer.de
Thu Jul 9 07:39:23 UTC 2009
Greg KH schrieb:
> On Wed, Jul 08, 2009 at 05:50:38PM +0200, Falco Hirschenberger wrote:
>> I think Linux can really benefit from an open kernel-based GigEVision
>> GigEVision is a proprietary closed standard for controlling
>> high-quality video cameras over gigabit-ethernet. These cameras are
>> often used in industrial vision software. This driver can be a great
>> benefit for the industrial vision industry, because using small embedded
>> Linux systems is in the trend there.
>> Some manufacturers provide closed-source drivers for Linux because of
>> the NDA which they signed at the AIA (Automated Imaging Association).
>> , 
>> Some provide no drivers but I think these cameras will work with a
>> generic driver because they have to implement the standard to get certified.
>> I have written a proof-of-concept userlevel driver by means of sniffing
>> and reverse-engineering, but some features are missing and I think I
>> will need some help to implement the rest. Btw. a kernel driver would
>> perform a lot better.
> Why would it perform better? You can send/receive ethernet packets just
> as fast from userspace as from within the kernel, right?
You're right, the send/rec. performance will not be increased, but
I know that there's a so called "filter driver" for GigEVision on
Windows systems. It's bypassing the UDP/IP stack which significantly
reduces the CPU-load on the system. And that's good because in most
cases the algorithms are running on the same machine.
But I think developing a filter driver is not the primary goal here.
> Or are you referring to the fact that the device should show up as a
> proper v4l2 device to userspace, and not need a custom userspace program
This would also be an option, but I suppose the v4l2 Interface is not
flexible enough for these complex cameras.
>> I hope this list is the correct place for this suggestion, feel free to
>> forward it to another place.
> It's a good place, hopefully people who wish to help out with this will
> contact you.
> But note, without specs, this will be a lot of work :)
As mentioned, I have a basic implementation. The so called PACKET_RESEND
functionality, which can request lost UDP packets is totally
unimplemented and will be the hardest part. But the whole reverse
engineering is rather easy with a normal packet sniffer and the
I hope there is some interest in the community.
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