[RFC/PATCH,4/5] v4l: Add V4L2_CID_EXPOSURE_BIAS camera control
Commit Message
The V4L2_CID_EXPOSURE_BIAS control allows for manual exposure
compensation when automatic exposure algorithm is enabled.
Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com>
---
Documentation/DocBook/media/v4l/controls.xml | 16 ++++++++++++++++
drivers/media/video/v4l2-ctrls.c | 1 +
include/linux/videodev2.h | 2 ++
3 files changed, 19 insertions(+), 0 deletions(-)
@@ -2691,6 +2691,22 @@ and 100000 for 10 seconds.</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 exposure
+compensation 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_EXPOSURE_AUTO_PRIORITY</constant> </entry>
<entry>boolean</entry>
</row><row><entry spanname="descr">When
@@ -578,6 +578,7 @@ const char *v4l2_ctrl_get_name(u32 id)
case V4L2_CID_IRIS_RELATIVE: return "Iris, Relative";
case V4L2_CID_DO_AUTO_FOCUS: return "Do Auto Focus";
case V4L2_CID_METERING_MODE: return "Metering Mode";
+ case V4L2_CID_EXPOSURE_BIAS: return "Exposure, Bias";
/* FM Radio Modulator control */
/* Keep the order of the 'case's the same as in videodev2.h! */
@@ -1633,6 +1633,8 @@ enum v4l2_metering_mode {
V4L2_METERING_MODE_SPOT,
};
+#define V4L2_CID_EXPOSURE_BIAS (V4L2_CID_CAMERA_CLASS_BASE+21)
+
/* 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)