Multi-media support by Device Drivers on Linux

[Kleus]

Hi,

I just spotted this forum, and I hope that there are some people here who might give me some tips for my issue. The issue is a small part of a Device Driver that I’m going to write for an unsupported webcam on Linux. Due to private reasons, the driver won’t be open-source. Therefore all the logic will be home made, but the code for e.g. the image processing can be fetched from available windows driver source code.

All this won’t be a problem, using the Internet and the LDD book will give enough input to create something. The part that isn’t quite clear now, is the multi-media support on Linux. A webcam driver on Windows mostly implements multi-media support by using DirectX output pins and filters between a driver output pin and video-in pin for e.g. Direct-Show. My main problem right now is getting some know-how on this item on the Linux OS.

The webcam will be available in the /dev as an own node and the specific functions will be controlled by Sysfs. What isn’t quite clear, is how to output the ‘streaming’ video from the driver to the /dev pin. I’m going to look how it’s implemented in other drivers, because I can’t find any documentation regarding this subject. How is this controlled on Linux and what kind of mechanism needs to be implemented in a driver to achieve this.

I’ve already searched a lot, but it isn’t clear to me. Can someone point me in the right direction?

Tnx in advance!

[ndevel]

Hi,
I did just a brief look into linux source code and maybe directory Documentation/video4linux could give some hints.

Regards,
ndevel.