Jim Gettys <[EMAIL PROTECTED]> wrote: > To do so, they need to be > able to use the device in as linear a fashion (photometrically) as > possible: disable gain control, black point processing, color balancing, > etc, which from looking at the sensor spec appears to be possible from a > quick perusal. Such sensors do a remarkable amount of signal processing > internally these days. > > I know V4L has facilities for controlling (most of) these features, that > you are hooking up in the sensor driver right now. Does V4L also have > facilities for completely disabling these features? Are there any > features of the chip that V4L does not support?
V4L2 has a fair number of predefined controls, there's a list at: http://v4l2spec.bytesex.org/spec/x488.htm#CONTROL-ID Some of them do what they want - disabling white balance, auto exposure control, etc. There is also a way to add driver-specific controls for the ones that are missing. So all of this can be handled. If it seems that any of those settings should be turned into standard V4L2 controls, that's easy enough to make happen. The big challenge is a story you've heard from me for a while: translating those controls into an appropriate set of OV7670 register settings. I have come to the conclusion that those settings really constitute a form of opaque firmware, and, without cooperation from OmniVision, they can be hard to get right. There's a lot of registers simply marked "reserved" in the spec, and there are undocumented ordering issues as well. It can all be done, eventually. jon _______________________________________________ Devel mailing list [email protected] http://mailman.laptop.org/mailman/listinfo/devel
