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| author | Sylwester Nawrocki <s.nawrocki@samsung.com> | 2012-03-06 07:06:55 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-05-14 14:03:47 -0300 |
| commit | d58083c949b3d76aba225be9f303ab5dab585064 (patch) | |
| tree | 3181333e4eacbdcc10743aee341ba6bbbd1adf1e | |
| parent | 515f32879a05bdb69f9b3f86f53db4c04b95e845 (diff) | |
| download | linux-d58083c949b3d76aba225be9f303ab5dab585064.tar.gz linux-d58083c949b3d76aba225be9f303ab5dab585064.tar.bz2 linux-d58083c949b3d76aba225be9f303ab5dab585064.zip | |
[media] V4L: Add camera exposure bias control
The camera may in some conditions incorrectly determine the exposure,
and a manual automatic exposure correction may be needed. This patch
adds V4L2_CID_AUTO_EXPOSURE_BIAS control which allows to add some
offset in the automatic exposure control loop, to compensate for
frame under- or over-exposure.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | Documentation/DocBook/media/v4l/controls.xml | 16 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-ctrls.c | 4 | ||||
| -rw-r--r-- | include/linux/videodev2.h | 2 |
3 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index e2ff0f98f08d..745b611c3593 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -2849,6 +2849,22 @@ remain constant.</entry> <row><entry></entry></row> <row> + <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant> </entry> + <entry>integer menu</entry> + </row><row><entry spanname="descr"> Determines the automatic +exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant> +control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant> +or <constant>APERTURE_PRIORITY</constant>. +It is expressed in terms of EV, drivers should interpret the values as 0.001 EV +units, where the value 1000 stands for +1 EV. +<para>Increasing the exposure compensation value is equivalent to decreasing +the exposure value (EV) and will increase the amount of light at the image +sensor. The camera performs the exposure compensation by adjusting absolute +exposure time and/or aperture.</para></entry> + </row> + <row><entry></entry></row> + + <row> <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant> </entry> <entry>integer</entry> </row><row><entry spanname="descr">This control turns the diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c index fdcb9e21d9d3..5bfef90e88ee 100644 --- a/drivers/media/video/v4l2-ctrls.c +++ b/drivers/media/video/v4l2-ctrls.c @@ -604,6 +604,7 @@ 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_AUTO_EXPOSURE_BIAS: return "Auto Exposure, Bias"; /* FM Radio Modulator control */ /* Keep the order of the 'case's the same as in videodev2.h! */ @@ -760,6 +761,9 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type, case V4L2_CID_RDS_TX_RADIO_TEXT: *type = V4L2_CTRL_TYPE_STRING; break; + case V4L2_CID_AUTO_EXPOSURE_BIAS: + *type = V4L2_CTRL_TYPE_INTEGER_MENU; + break; case V4L2_CID_USER_CLASS: case V4L2_CID_CAMERA_CLASS: case V4L2_CID_MPEG_CLASS: diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index 07bce86f3548..dfd209816df6 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -1707,6 +1707,8 @@ 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_AUTO_EXPOSURE_BIAS (V4L2_CID_CAMERA_CLASS_BASE+19) + /* 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) |