From d58083c949b3d76aba225be9f303ab5dab585064 Mon Sep 17 00:00:00 2001 From: Sylwester Nawrocki Date: Tue, 6 Mar 2012 07:06:55 -0300 Subject: [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 Signed-off-by: Kyungmin Park Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/media/v4l/controls.xml | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'Documentation') 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 @@ -2848,6 +2848,22 @@ remain constant. + + V4L2_CID_EXPOSURE_BIAS  + integer menu + Determines the automatic +exposure compensation, it is effective only when V4L2_CID_EXPOSURE_AUTO +control is set to AUTO, SHUTTER_PRIORITY +or APERTURE_PRIORITY. +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. +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. + + + V4L2_CID_PAN_RELATIVE  integer -- cgit v1.2.3