Re(2): Quickcam device driver for Linux

davem@magnet.com,Internet writes:
> Note that there already has been a linux kernel driver available
>called "qcam-kernel-0.1"
>. I doubt it's maintained because it's been
>the same version for over a year now.. I use i
>t for a realtime gif
>or jpeg server push program I wrote. It only spits out raw image info
>but then I use libjpeg to compress it for me. I didn't see any need
>for the image
> conversion to occur within the kernel module.

On Fri, 13 Jun 1997, Ludovic Bertsch wrote:

>> I was wondering if it w
>ould be a good idea to provide a kernel

>> driver for the quick-cam...


>>   The interface would be for example /dev/cam2gif to give the user

>> a real-time gif file each time it is read on.

>> Of course this would be slower than direct hardware access, but if you 

>> changed your hardware, you would just need to change your kernel driver,

>> and NOT rewrite all your software.


>>   There should be better image formats than gif for real-time image

>> acquisition that would be included...


>>   You should also 
>be able to define the image size or different

>> parameter (with IOCTLS? or a writable device driver?)


>>   I think this could be done with a library, but it would be cleaner

>> and more general to program it in the kernel.


>>   What do you think about that? Good idea? Bad idea? Why?


In fact, it would generally be a bad idea to do image conversion within the
kernel.  Kernel drivers should generally be short and sweet, just do the
I/O and get out. Let the user space appsl do the high level stuff, in user
space, you have way more resource to play with, and you don't have to worry
about corrupting the kernel and destabalizing the entire system with buggy
code, etc...  

Why not just write a user space app with all the features you mention that
just polls the existing QuickCam driver and spews out the appropriately
converted images?

Mike Sharkey
X11 Development
SoftArc Inc.

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