Re: Quickcam device driver for Linux
While writing a quickcam driver is an interesting exercise, I think
that it's the wrong way to provide access to the camera.
I feel that the best solution is to write a simple camera server process.
The server opens a socket, listens for picture requests, takes
the pictures and returns the bytes to the caller.
1. The camera server is the only process that has to run as root.
2. The camera server can serialize requests from multiple clients.
3. The clients can be running on other machines, thus you can overlap
picture taking with picture processing.
4. It's much easier to experiment with and debug a user-level
server program than a device driver.
5. A user-level program is much more portable across operating
systems than a device driver.
A simple server is easy to write, but you can imagine writing a
more sophisticated one that could, for example, send back picture deltas
rather than the whole picture. This would be useful where network
bandwidth is a problem. Of you could have the server do the conversion
to gif or jpeg in those cases when you want a dumb client to get something
it can display.