Hi! > > > According to the docs V4L2_CID_EXPOSURE_ABSOLUTE is in 100 usec units. > > > > > > OTOH V4L2_CID_EXPOSURE has no defined unit, so it's a better fit IMO. > > > >Way more drivers appear to be using EXPOSURE than EXPOSURE_ABSOLUTE, too. > > > > > > Done, switched to V4L2_CID_EXPOSURE. It's true, this control is not > > > taking 100 usec units, so unit-less is better. > > > > Thanks. If you know the units, it would be of course better to use > > right units... > > Steve: what's the unit in this case? Is it lines or something else? > > Pavel: we do need to make sure the user space will be able to know the unit, > too. It's rather a case with a number of controls: the unit is known but > there's no API to convey it to the user. > > The exposure is a bit special, too: granularity matters a lot on small > values. On most other controls it does not. Yeah. Basically problem with exposure is that the control is logarithmic; by using linear scale we got too much resolution at long times and too little resolution at short times. (Plus, 100 usec ... n900 can do times _way_ shorter than that.) Anyway, even u32 gives us enough range, but I so the linear/log confusion does not matter. But it would be nicer if values were in 10 usec or usec, not 100 usec... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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