(A bit late, sorry) On Thursday 07 March 2013 22:37:26 Guennadi Liakhovetski wrote: > On Wed, 6 Mar 2013, Christian Rhodin wrote: > > Hi, > > > > I'm looking for some guidance on the correct way to handle a new pixel > > format. What I'm dealing with is a CMOS image sensor that supports > > dynamic switching between linear and iHDR modes. iHDR stands for > > "interlaced High Dynamic Range" and is a mode where odd and even lines > > have different exposure times, typically with an 8:1 ratio. When I > > started implementing a driver for this sensor I used > > "V4L2_MBUS_FMT_SGRBG10_1X10" as the format for the linear mode and > > defined a new format "V4L2_MBUS_FMT_SGRBG10_IHDR_1X10" for the iHDR > > mode. I used the format to control which mode I put the sensor in. But > > now I'm having trouble switching modes without reinitializing the > > sensor. Does anyone (everyone?) have an opinion about the correct way > > to implement this? I'm thinking that the format is overloaded because > > it represents both the size and type of the data. Should I use a single > > format and add a control to switch the mode? > > I would vote for a single format with a control, maybe even somehow > cluster it with the normal exposure, but I'm not an expert in that, not > sure if it would make sense. >From the above explanation about iHDR I assume that enabling iHDR mode produces an image with the same resolution as linear mode, not an image with 8 times the number of lines compared to the linear mode. Please correct me if I'm wrong. If my understanding of iHDR mode is correct, I agree with Guennadi. I don't think enabling iHDR changes the format, it "just" modifies the exposure time algorithm. A V4L2 control would thus be better than adding an iHDR variant to all existing formats. -- 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
