On Mon, Apr 24, 2017 at 06:49:04PM +0300, Jyri Sarha wrote: > On 04/24/17 18:13, Ville Syrjälä wrote: > >> What about the uapi structs? In the patch there is an explicit struct > >> naming each coefficient for what they are for in YCbCr to RGB > >> conversion. Is this Ok, or should we go with a generic (CTM style) > >> matrix, that could be used for RGB to YCbCr conversion too? > > Not sure what we're talking about here, but like I said I think we > > should stick to a fairly limited set of standard props and just have > > each driver map the hardware resources to them as best they can. > > > > Just about the implementation detail, if we should have a separate uapi > struct for YCbCr to RGB CSC and RGB to YCbCr CSC. If we are going to use > the same struct, then we could as well use the already existing CTM struct. > > > If you just have csc+(de)gamma then I guess it might make sense > > to just expose the YCbCr->RGB and degamma. If you have > > degamma+csc+gamma then it might make sense to expose both > > YCbCr->RGB, degamma, CTM, and gamma, and just refuse any > > combination that can't be done. Eg. can't do YCbCr->RGB if > > degamma is used, and YCbCr->RGB + CTM would require multiplying > > the matrices together which you may or may not want to bother > > with, I guess we could try to put some matrix math helpers into > > the core to make such things less painful for drivers? > > In fact we have plane specific YCbCr to RGB CSC (only preoffset > possible), then (per crtc) gamma table, and finally a (per crtc) RGB to > YCbCr CSC with optional post offset (so it can be used either as CSC or > CTM). So with that plane hw you could perhaps do: - YCbCr->RGB if you input is not linear, but then you must blend using non-linear data - colorspace conversion if your input is alredy linear And with your crtc hw you could do: - degamma + CTM - gamma + RGB->YCbCr -- Ville Syrjälä Intel OTC _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
