Laurent, On Mon, Mar 26, 2012 at 2:25 AM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Joshua, > > On Sunday 25 March 2012 23:13:02 Joshua Hintze wrote: >> Alright I made some progress on this. >> >> I can access the Mt9p031 registers that are exposed using a command such as >> >> ./yavta -l /dev/v4l-subdev8 to list the available controls. Then I can >> set the exposure and analog gain with >> ./yavta --set-control '0x00980911 1500' /dev/v4l-subdev8 <--- This >> seems to give the desired effect. >> >> Note that ./yavta -w (short option for --set-control) gives a seg >> fault for me. Possible bug in yavta?? > > That's strange, I use -w all the time and haven't noticed any segfault. Can > you compile yavta with debugging information and provide some context ? > Then this must be my problem. I slightly modified yavta to output to stdout for net cat streaming to mplayer on my desktop. I probably didn't get the short options string correct. >> Now I'm working on fixing the white balance. In my office the incandescent >> light bulbs give off a yellowish tint late at night. I've been digging >> through the omap3isp code to figure out how to enable the automatic white >> balance. I was able to find the private IOCTLs for the previewer and I was >> able to use VIDIOC_OMAP3ISP_PRV_CFG. Using this IOCTL I adjusted the >> OMAP3ISP_PREV_WB, OMAP3ISP_PREV_BLKADJ, and OMAP3ISP_PREV_RGB2RGB. >> >> Since I wasn't sure where to start on adjusting these values I just set them >> all to the TRM's default register values. However when I did so a strange >> thing occurred. What I saw was all the colors went to a decent color. I'm >> curious if anybody can shed some light on the best way to get a high quality >> image. Ideally if I could just set a bit for auto white balance and auto >> exposure that could be good too. > > The ISP doesn't implement automatic white balance. It can apply white > balancing (as well as other related processing), but computing values for > those parameters needs to be performed in userspace. The ISP statistics engine > engine can help speeding up the process, but the AEWB algorithm must be > implemented in your application. > Dang, I'll have to look up some AEWB algorithms. I'm curious why TI would have this register bit then (AEW_EN bit 15 in H3A_PCR)? Is this the same for auto focus and auto exposure? Meaning that I'll need to get information from the histogram/statistics to adjust focus and exposure times? Thanks, Josh > -- > 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
