Hi Sylwester, On Tue, May 15, 2012 at 11:28:03PM +0200, Sylwester Nawrocki wrote: > Hi Sakari, > > On 05/14/2012 02:02 AM, Sakari Ailus wrote: > > Hi Sylwester, > > > > Thanks for the patch. I noticed your pull req; I hope you could take into > > account a few more comments. :) > > Thank you for your comments, I'll try to come up with a fix up patch. > > > On Thu, May 10, 2012 at 12:30:38PM +0200, Sylwester Nawrocki wrote: > >> This patch adds V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE control which is > >> an extended version of the V4L2_CID_AUTO_WHITE_BALANCE control, > >> including white balance presets. The following presets are defined: > >> > >> - V4L2_WHITE_BALANCE_INCANDESCENT, > >> - V4L2_WHITE_BALANCE_FLUORESCENT, > >> - V4L2_WHITE_BALANCE_FLUORESCENT_H, > >> - V4L2_WHITE_BALANCE_HORIZON, > >> - V4L2_WHITE_BALANCE_DAYLIGHT, > >> - V4L2_WHITE_BALANCE_FLASH, > >> - V4L2_WHITE_BALANCE_CLOUDY, > >> - V4L2_WHITE_BALANCE_SHADE. > >> > >> Signed-off-by: HeungJun Kim<riverful....@samsung.com> > >> Signed-off-by: Sylwester Nawrocki<s.nawro...@samsung.com> > >> Signed-off-by: Kyungmin Park<kyungmin.p...@samsung.com> > >> Acked-by: Hans de Goede<hdego...@redhat.com> > >> --- > >> Documentation/DocBook/media/v4l/controls.xml | 70 > >> ++++++++++++++++++++++++++ > >> drivers/media/video/v4l2-ctrls.c | 17 +++++++ > >> include/linux/videodev2.h | 14 ++++++ > >> 3 files changed, 101 insertions(+) > >> > >> diff --git a/Documentation/DocBook/media/v4l/controls.xml > >> b/Documentation/DocBook/media/v4l/controls.xml > >> index 40e6485..85d1ca0 100644 > >> --- a/Documentation/DocBook/media/v4l/controls.xml > >> +++ b/Documentation/DocBook/media/v4l/controls.xml > >> @@ -3022,6 +3022,76 @@ camera sensor on or off, or specify its strength. > >> Such band-stop filters can > >> be used, for example, to filter out the fluorescent light > >> component.</entry> > >> </row> > >> <row><entry></entry></row> > >> + > >> + <row id="v4l2-auto-n-preset-white-balance"> > >> + <entry > >> spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant> </entry> > >> + <entry>enum v4l2_auto_n_preset_white_balance</entry> > >> + </row><row><entry spanname="descr">Sets white balance to automatic, > >> +manual or a preset. The presets determine color temperature of the light > >> as > >> +a hint to the camera for white balance adjustments resulting in most > >> accurate > >> +color representation. The following white balance presets are listed in > >> order > >> +of increasing color temperature.</entry> > >> + </row> > >> + <row> > >> + <entrytbl spanname="descr" cols="2"> > >> + <tbody valign="top"> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant> </entry> > >> + <entry>Manual white balance.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant> </entry> > >> + <entry>Automatic white balance adjustments.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant> </entry> > >> + <entry>White balance setting for incandescent (tungsten) > >> lighting. > >> +It generally cools down the colors and corresponds approximately to > >> 2500...3500 K > >> +color temperature range.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant> </entry> > >> + <entry>White balance preset for fluorescent lighting. > >> +It corresponds approximately to 4000...5000 K color temperature.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant> </entry> > >> + <entry>With this setting the camera will compensate for > >> +fluorescent H lighting.</entry> > >> + </row> > > > > I don't remember for quite sure if I replied to this already... what's the > > diff between the above two? > > No, you didn't, otherwise I would certainly remember that ;) > > V4L2_WHITE_BALANCE_FLUORESCENT_H is for newer, daylight calibrated fluorescent > lamps. So this preset will generally cool down the colours less than > V4L2_WHITE_BALANCE_FLUORESCENT. I was even thinking about a separate control > for V4L2_WHITE_BALANCE_FLUORESCENT, since some ISPs have several presets for > fluorescent lighting. I dropped that idea finally though.
I don't know about the daylight calibrated ones, but the older ones often tend to give colder light. Nevertheless, I think it'd be good to mention this in the documentation. I couldn't thave guessed it. :) > > The colour temperature of the fluorescent light depends on the lamp; 2500 K > > is not uncommon here in Finland. It's the spectrum that's different from > > incandescents, not necessarily the colour temperature. > > > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant> </entry> > >> + <entry>White balance setting for horizon daylight. > >> +It corresponds approximately to 5000 K color temperature.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant> </entry> > >> + <entry>White balance preset for daylight (with clear sky). > >> +It corresponds approximately to 5000...6500 K color temperature.</entry> > >> + </row> > >> + <row> > >> + > >> <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant> </entry> > >> + <entry>With this setting the camera will compensate for the > >> flash > >> +light. It slightly warms up the colors and corresponds roughly to > >> 5000...5500 K > >> +color temperature.</entry> > > > > This also depends heavily on the type of the flash. > > OK, I'm going to remove this one, and for V4L2_WHITE_BALANCE_FLUORESCENT as > well. > I would prefer to keep the remaining ones though. Sounds good to me. Cheers, -- Sakari Ailus e-mail: sakari.ai...@iki.fi jabber/XMPP/Gmail: sai...@retiisi.org.uk -- 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
