Lots of fun with w3cam and friends

[Peter Pregler]

On 28-Nov-99 Nick Holloway wrote:
> 
> With 0.4.3, the reset appears to happen every time.  So, when used
> indoors, you get a picture (from the default exposure), but outside you
> get just white.

This reset is a bug I am aware of. The driver is meant to save the exposure and
color-balance state. It does save the state, but there is something wrong with
the reinitiasation of the exposure.

> With single frame captures, I don't think just using the last exposure
> will be valid.  I think waiting until the auto-exposure has settled down
> before grabbing the frame would be valid.

I think this would really kill any performance and there is no API to control
this. My solution to this problem was to save the current camera state and use 
that as the starting point for the new capture. I have to test it but I think if
implemented correctly this should result in auto-exposure taking place even in
single frame capture mode, just a bit slower. Of cause any other reasonable
ideas are highly welcome.

> I don't know if you can always tell the difference between a single frame
> grab, and a stream grab.  It appears that "vidcat" uses capture_frame,
> and "gqcam" doesn't, but I don't know if this is universally true.

Nope, right now the camera is used in just one way, single frame grab mode.

-Peter

-------------------------------
Even the thought that a ship was waiting to take him back to Earth
did not wipe out the sense of loss he felt at that moment.
-------------------------------
Email: Peter.Pregler@risc.uni-linz.ac.at
Peter Pregler / RISC, University of Linz, Austria
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