BUG: Autobrightness is unstable
I'm trying to uso motion outdoor with a Creative NX Ultra webcam.
I've activated autobrightness but the image can't reach a stable state and oscillates between very dark and
white.
I tested also with a Quickcam Express there's the same problem.
Test case
Environment
Motion version: |
3.2.2 |
ffmpeg version: |
|
Shared libraries: |
|
Server OS: |
FC 2, 2.6.12.1 |
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TWikiGuest - 15 Aug 2005
Follow up
Fix record
I think I have fixed it. At least for some. The fix is in release 3.2.3 (16 Aug 2005).
Did you run with pre_capture > 0 or minimum_motion_frames > 1? If so then one bug is now fixed.
If your camera already adjusts brightness then it may not work anyway.
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KennethLavrsen - 16 Aug 2005
> Did you run with pre_capture > 0 or minimum_motion_frames > 1? If so then one bug is now fixed.
No, pre_capture = 0 , minimum_motion_frames = 1
I've tried also version 3.2.3 but there are oscillations.
> If your camera already adjusts brightness then it may not work anyway.
It hasn't autobrightness
I played with camera brightness control and I noticed it has a very non-linear response. (Eg. from 20000 to 26300 there's little change, from 26300 to 26400 the image changes a lot). This may be the reason.
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TWikiGuest - 17 Aug 2005
Yes. If the camera does not have a linear or close to linear response then it is close to impossible to make a regulation loop that works in practical without making a unique one for this one type camera which would be a bit of an overkill. If I make the steps too small I risk that some camera to not regulate at all.
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KennethLavrsen - 17 Aug 2005