Hi Sylwester, I'll continue this conversation to the Laurent's reply. So, please check the others. > -----Original Message----- > From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- > owner@xxxxxxxxxxxxxxx] On Behalf Of Sylwester Nawrocki > Sent: Wednesday, December 28, 2011 10:35 PM > To: HeungJun, Kim > Cc: linux-media@xxxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; hverkuil@xxxxxxxxx; > sakari.ailus@xxxxxx; laurent.pinchart@xxxxxxxxxxxxxxxx; > kyungmin.park@xxxxxxxxxxx; Hans de Goede > Subject: Re: [RFC PATCH 1/4] v4l: Add V4L2_CID_PRESET_WHITE_BALANCE menu > control > > Hi, > > On 12/28/2011 07:23 AM, HeungJun, Kim wrote: > > It adds the new CID for setting White Balance Preset. This CID is provided as > > menu type using the following items: > > 0 - V4L2_WHITE_BALANCE_INCANDESCENT, > > 1 - V4L2_WHITE_BALANCE_FLUORESCENT, > > 2 - V4L2_WHITE_BALANCE_DAYLIGHT, > > 3 - V4L2_WHITE_BALANCE_CLOUDY, > > 4 - V4L2_WHITE_BALANCE_SHADE, > > I have been also investigating those white balance presets recently and noticed > they're also needed for the pwc driver. Looking at > drivers/media/video/pwc/pwc-v4l2.c there is something like: > > const char * const pwc_auto_whitebal_qmenu[] = { > "Indoor (Incandescant Lighting) Mode", > "Outdoor (Sunlight) Mode", > "Indoor (Fluorescent Lighting) Mode", > "Manual Mode", > "Auto Mode", > NULL > }; > > static const struct v4l2_ctrl_config pwc_auto_white_balance_cfg = { > .ops = &pwc_ctrl_ops, > .id = V4L2_CID_AUTO_WHITE_BALANCE, > .type = V4L2_CTRL_TYPE_MENU, > .max = awb_auto, > .qmenu = pwc_auto_whitebal_qmenu, > }; > > ... > > cfg = pwc_auto_white_balance_cfg; > cfg.name = v4l2_ctrl_get_name(cfg.id); > cfg.def = def; > pdev->auto_white_balance = v4l2_ctrl_new_custom(hdl, &cfg, NULL); > > So this driver re-defines V4L2_CID_AUTO_WHITE_BALANCE as a menu control > with custom entries. That's interesting... However it works in practice > and applications have access to what's provided by hardware. > Perhaps V4L2_CID_AUTO_WHITE_BALANCE_TEMPERATURE would be a better fit for > that :) > > Nevertheless, redefining standard controls in particular drivers sounds > a little dubious. I wonder if this is a generally agreed approach ? > > Then, how does your V4L2_CID_PRESET_WHITE_BALANCE control interact with > V4L2_CID_AUTO_WHITE_BALANCE control ? Does V4L2_CID_AUTO_WHITE_BALANCE need > to be set to false for V4L2_CID_PRESET_WHITE_BALANCE to be effective ? > > > Signed-off-by: HeungJun, Kim <riverful.kim@xxxxxxxxxxx> > > Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > > --- > > Documentation/DocBook/media/v4l/controls.xml | 38 > ++++++++++++++++++++++++++ > > drivers/media/video/v4l2-ctrls.c | 12 ++++++++ > > include/linux/videodev2.h | 9 ++++++ > > 3 files changed, 59 insertions(+), 0 deletions(-) > > > > diff --git a/Documentation/DocBook/media/v4l/controls.xml > b/Documentation/DocBook/media/v4l/controls.xml > > index c0422c6..350c138 100644 > > --- a/Documentation/DocBook/media/v4l/controls.xml > > +++ b/Documentation/DocBook/media/v4l/controls.xml > > @@ -2841,6 +2841,44 @@ it one step further. This is a write-only > control.</entry> > > </row> > > <row><entry></entry></row> > > > > + <row id="v4l2-preset-white-balance"> > > + <entry > spanname="id"><constant>V4L2_CID_PRESET_WHITE_BALANCE</constant> </entry> > > Wouldn't V4L2_CID_WHITE_BALANCE_PRESET be better ? > > > + <entry>enum v4l2_preset_white_balance</entry> > > + </row><row><entry spanname="descr">This control sets > > + the camera's white balance by the presets. These preset is provided > > + by the type of the enum values which are generally provided > > + by several digital cameras. But, it dosen't mean that the specific > > s/dosent'/doesn't > > > + preset always can be counterposed with the unique white balance value. > > + This is a read/write control.</entry> > > We probably only need such a remark if a control is read-only or write-only. > > > + </row> > > + <row> > > + <entrytbl spanname="descr" cols="2"> > > + <tbody valign="top"> > > + <row> > > + > <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant> </entry> > > + <entry>White Balance Incandescent/Tungster preset.</entry> > > s/Tungster/Tungsten > > If we are to have these presets, then we need to be a little bit more verbose > about what they mean. To avoid situation similar to V4L2_CID_COLORFX control > where nobody knows exactly what's an exact meaning of the menu items. > > > + </row> > > + <row> > > + > <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant> </entry> > > + <entry>White Balance Fluorescent preset.</entry> > > + </row> > > + <row> > > + > <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant> </entry> > > + <entry>White Balance Daylight preset.</entry> > > + </row> > > + <row> > > + > <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant> </entry> > > + <entry>White Balance Cloudy preset.</entry> > > + </row> > > + <row> > > + > <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant> </entry> > > + <entry>White Balance Share preset.</entry> > > s/Share/Shade > > > + </row> > > + </tbody> > > + </entrytbl> > > + </row> > > + <row><entry></entry></row> > > + > > <row> > > <entry > spanname="id"><constant>V4L2_CID_PRIVACY</constant> </entry> > > <entry>boolean</entry> > > diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2- > ctrls.c > > index 0f415da..f51b576 100644 > > --- a/drivers/media/video/v4l2-ctrls.c > > +++ b/drivers/media/video/v4l2-ctrls.c > > @@ -234,6 +234,14 @@ const char * const *v4l2_ctrl_get_menu(u32 id) > > "Vivid", > > NULL > > }; > > + static const char * const preset_white_balance[] = { > > + "Incandescent", > > + "Fluorescent", > > + "Daylight", > > + "Cloudy", > > + "Shade", > > + NULL, > > + }; > > static const char * const tune_preemphasis[] = { > > "No Preemphasis", > > "50 useconds", > > @@ -390,6 +398,8 @@ const char * const *v4l2_ctrl_get_menu(u32 id) > > return camera_exposure_auto; > > case V4L2_CID_COLORFX: > > return colorfx; > > + case V4L2_CID_PRESET_WHITE_BALANCE: > > + return preset_white_balance; > > case V4L2_CID_TUNE_PREEMPHASIS: > > return tune_preemphasis; > > case V4L2_CID_FLASH_LED_MODE: > > @@ -567,6 +577,7 @@ const char *v4l2_ctrl_get_name(u32 id) > > case V4L2_CID_PRIVACY: return "Privacy"; > > case V4L2_CID_IRIS_ABSOLUTE: return "Iris, Absolute"; > > case V4L2_CID_IRIS_RELATIVE: return "Iris, Relative"; > > + case V4L2_CID_PRESET_WHITE_BALANCE: return "White Balance, Preset"; > > > > /* FM Radio Modulator control */ > > /* Keep the order of the 'case's the same as in videodev2.h! */ > > @@ -680,6 +691,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum > v4l2_ctrl_type *type, > > case V4L2_CID_MPEG_STREAM_VBI_FMT: > > case V4L2_CID_EXPOSURE_AUTO: > > case V4L2_CID_COLORFX: > > + case V4L2_CID_PRESET_WHITE_BALANCE: > > case V4L2_CID_TUNE_PREEMPHASIS: > > case V4L2_CID_FLASH_LED_MODE: > > case V4L2_CID_FLASH_STROBE_SOURCE: > > diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h > > index 3d62631..a842de0 100644 > > --- a/include/linux/videodev2.h > > +++ b/include/linux/videodev2.h > > @@ -1618,6 +1618,15 @@ enum v4l2_exposure_auto_type { > > #define V4L2_CID_IRIS_ABSOLUTE (V4L2_CID_CAMERA_CLASS_BASE+17) > > #define V4L2_CID_IRIS_RELATIVE (V4L2_CID_CAMERA_CLASS_BASE+18) > > > > +#define V4L2_CID_PRESET_WHITE_BALANCE (V4L2_CID_CAMERA_CLASS_BASE+19) > > +enum v4l2_preset_white_balance { > > + V4L2_WHITE_BALANCE_INCANDESCENT = 0, > > + V4L2_WHITE_BALANCE_FLUORESCENT = 1, > > + V4L2_WHITE_BALANCE_DAYLIGHT = 2, > > + V4L2_WHITE_BALANCE_CLOUDY = 3, > > + V4L2_WHITE_BALANCE_SHADE = 4, > > +}; > > + > > /* FM Modulator class control IDs */ > > #define V4L2_CID_FM_TX_CLASS_BASE (V4L2_CTRL_CLASS_FM_TX | 0x900) > > #define V4L2_CID_FM_TX_CLASS (V4L2_CTRL_CLASS_FM_TX | 1) > > -- > > Thanks, > Sylwester > -- > 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 -- 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
