Hi Laurent, On Fri, Oct 07, 2022 at 11:20:13AM +0300, Laurent Pinchart wrote: > Hi Krzysztof, > > On Fri, Oct 07, 2022 at 07:28:46AM +0200, Krzysztof Hałasa wrote: > > Laurent Pinchart writes: > > > > > I'm tempted to drop support for the colour gains really, and turn the > > > V4L2_CID_GAIN into V4L2_CID_DIGITAL_GAIN. Digital colour gains can still > > > be useful on platforms that have no ISP, but I think we need an array of > > > gains in that case, not abusing V4L2_CID_RED_BALANCE and > > > V4L2_CID_BLUE_BALANCE. Any objection ? > > > > I'm fine with spliting it into analog/digital as long as there is a way > > to set individual R/G/B (digital) gain values. > > With the controls we have today in V4L2, we could map > V4L2_CID_RED_BALANCE and V4L2_CID_BLUE_BALANCE to the red and blue > digital gains, with V4L2_CID_DIGITAL_GAIN setting the global digital > gain. > > I'm tempted to bite the bullet and define a new > V4L2_CID_DIGITAL_COLOR_GAINS control that would expose an array of > gains, but if we extend the API for that, I think we should also include > support for HDR at the same time, with at least T1/T2 sets of gains. > > Sakari, any opinion ? Would you use multiple controls for that or just a single one? The size of a matrix control is not changeable dynamically so I presume the driver would create as large control as needed, and program to hardware as much as needed. -- Regards, Sakari Ailus
