Hi Laurent, On 01/03/2012 02:55 PM, Laurent Pinchart wrote: >>>>> parameter. We also need to discuss how the af statistics window >>>>> configuration is done. I'm not certain there could even be a >>>>> standardised >>>> >>>> Do we need multiple windows for AF statistics ? >>>> >>>> If not, I'm inclined to use four separate controls for window >>>> configuration. (X, Y, WIDTH, HEIGHT). This was Hans' preference in >>>> previous discussions [1]. >>> >>> For the OMAP3 ISP we need multiple statistics windows. AEWB can use more >>> than 32 windows. Having separate controls for that wouldn't be >>> practical. >> >> OK, so the control API in current form doesn't seem capable of setting up >> the statistics windows. There is also little space in struct >> v4l2_ext_control for any major extensions. >> >> We might need to define dedicated set of selection targets in the selection >> API for handling multiple windows. >> >> Yet, to avoid forcing applications to use the selection API where >> rectangles aren't needed - only single spot coordinates, how about >> defining following two controls ? >> >> * AF spot coordinates when focus mode is set to V4L2_AUTO_FOCUS_MODE_SPOT >> >> - V4L2_CID_AUTO_FOCUS_POSITION_X - horizontal position in pixels relative >> to the left of frame >> - V4L2_CID_AUTO_FOCUS_POSITION_Y - vertical position in pixels relative >> to the top of frame > > What about a point control type instead ? :-) X and Y coordinates could be > stored on 32 bits each. That's more appealing than two separate controls :-) If Hans agrees to add a point control type (fingers crossed :)) I could prepare relevant patch to see how it looks like. I've analysed roughly what would need to be changed, the effort is quite significant but not so invasive for drivers. I thought about using new V4L2_CTRL_FLAG* for VIDIOC_QUERYCTRL to indicate which field of the point data structure is queried. The only real problem seem to be events, I can't see simple method for adding two sets of min/max/step/def values to the control event payload. There would probably have to be two separate control change events for each point structure field. -- 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
