Hi Ivan,
2009/3/18 Ivan T. Ivanov <iiva...@mm-sol.com>: > Hi Kim, > > On Wed, 2009-03-18 at 13:32 +0900, Dongsoo, Nathaniel Kim wrote: >> Hello, >> >> I accidently realized today that I was using white balance control in wrong >> way. >> >> As far as I understand we've got >> >> V4L2_CID_AUTO_WHITE_BALANCE which activate auto white balance >> adjustment in runtime, >> V4L2_CID_DO_WHITE_BALANCE_TEMPERATURE specifying absolute kelvin value >> >> but can't get what V4L2_CID_DO_WHITE_BALANCE is for. > > My understanding is that V4L2_CID_DO_WHITE_BALANCE enable/disable > white balance processing, while with > V4L2_CID_DO_WHITE_BALANCE_TEMPERATURE you can specify explicitly > ambient temperature. OK, then according to your explanation DO_WHITE_BALANCE is only for AUTO_WHITE_BALANCE. Am I following? Because only auto white balance mode does processing and make changes in color temperature while preview is working. > >> >> I think after issuing V4L2_CID_AUTO_WHITE_BALANCE and >> V4L2_CID_WHITE_BALANCE_TEMPERATURE, >> the white balance functionality works immediately. Isn't it right? >> >> What exactly is the button type V4L2_CID_DO_WHITE_BALANCE for? Because >> the V4L2 API document says that "(the value is ignored)". Does that >> mean that even we have issued V4L2_CID_AUTO_WHITE_BALANCE and >> V4L2_CID_WHITE_BALANCE_TEMPERATURE, we can't see the white balance >> working at that moment? >> >> And one more thing. If I want to serve several white balance presets, >> like cloudy, dawn, sunny and so on, what should I do? >> I think it should be supported as menu type, but most of drivers are >> using white balance CID with integer type...then what should I do? >> Define preset names with kelvin number like this? > > I also will like to see controls which specify different kind of > white balance mode (cloudy, sunny, tungsten...). in this case > we can thing about V4L2_CID_WHITE_BALANCE_TEMPERATURE as 'manual' > mode, and let other modes to be handled by some clever algorithms ;). > If there isn't any driver which is driving white balance with menu type, there should be some reason for that. I want to make it clear if I could. I hope Hans or other maintainer could answer this. Cheers, Nate > IIvanov > > >> >> #define WB_CLOUDY 8000 >> >> Pretty confusing... anyone knows what should I do? >> >> Nate >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-media" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- ======================================================== DongSoo, Nathaniel Kim Engineer Mobile S/W Platform Lab. Digital Media & Communications R&D Centre Samsung Electronics CO., LTD. e-mail : dongsoo....@gmail.com dongsoo45....@samsung.com ======================================================== -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
