Hi Sakari, On 04/17/2012 06:09 PM, Sakari Ailus wrote: > Hi Sylwester, > > On Tue, Apr 17, 2012 at 12:09:51PM +0200, Sylwester Nawrocki wrote: >> The V4L2_CID_3A_LOCK bitmask control allows applications to pause >> or resume the automatic exposure, focus and wite balance adjustments. >> It can be used, for example, to lock the 3A adjustments right before >> a still image is captured, for pre-focus, etc. >> The applications can control each of the algorithms independently, >> through a corresponding control bit, if driver allows that. > > How is disabling e.g. focus algorithm different from locking focus? The difference looks quite obvious to me. When some AUTO control is switched from auto to manual mode there is no guarantee about the related parameters the device will end up. E.g. lens may be positioned into default position, rather than kept at current one, exposure might be set to manual value from before AE was enabled, etc. I've seen separate registers at the sensor interfaces for AE, AWB locking/unlocking and for disabling/enabling those algorithms. With the proposed control applications can be sure that, for example, exposure is retained when the V4L2_CID_3A_LOCK is set. Does it answer your question ? -- Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
