Hi Laurent, On Tue, 29 Nov 2016, Laurent Pinchart wrote: > Hi Guennadi, > > (CC'ing Sakari) > > On Monday 28 Nov 2016 15:18:03 Guennadi Liakhovetski wrote: > > Hi, > > > > Has anyone already considered supporting 3A (e.g. auto-exposure) Region of > > Interest selection? In UVC this is the "Digital Region of Interest (ROI) > > Control." Android defines ANDROID_CONTROL_AE_REGIONS, > > ANDROID_CONTROL_AWB_REGIONS, ANDROID_CONTROL_AF_REGIONS. The UVC control > > defines just a single rectangle for all (supported) 3A functions. That > > could be implemented, defining a new selection target. However, Android > > allows arbitrary numbers of ROI rectangles with associated weights. Any > > ideas? > > Selections could be used, possibly with an update to the API to allow indexing > selections for a given target. We'd be missing weights though. Another option > would be to use compound controls. I talked to Hans online and he is in favour of a compound control for ROI as well, which is also fine with me. Working on an implementation I realised, that struct v4l2_query_ext_ctrl has min, max, step and default values as 64-bit fields, which isn't enough for ROI. Shall they all be replaced with unions of original values and pointers? As long as pointers don't exceed 64 bits, we'll stay binary compatible. Or do we use those fields similar to the STRING type to specify min, max, default number of ROIs and a size of one ROI in step? I guess we should go with the latter. Thanks Guennadi > -- > Regards, > > Laurent Pinchart > -- 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
