From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml | 155 +++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml (limited to 'Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml') diff --git a/Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml b/Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml new file mode 100644 index 00000000..06197323 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-subdev-g-crop.xml @@ -0,0 +1,155 @@ + + + ioctl VIDIOC_SUBDEV_G_CROP, VIDIOC_SUBDEV_S_CROP + &manvol; + + + + VIDIOC_SUBDEV_G_CROP + VIDIOC_SUBDEV_S_CROP + Get or set the crop rectangle on a subdev pad + + + + + + int ioctl + int fd + int request + struct v4l2_subdev_crop *argp + + + + + int ioctl + int fd + int request + const struct v4l2_subdev_crop *argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_SUBDEV_G_CROP, VIDIOC_SUBDEV_S_CROP + + + + argp + + + + + + + + + Description + + + Experimental + This is an experimental + interface and may change in the future. + + + To retrieve the current crop rectangle applications set the + pad field of a &v4l2-subdev-crop; to the + desired pad number as reported by the media API and the + which field to + V4L2_SUBDEV_FORMAT_ACTIVE. They then call the + VIDIOC_SUBDEV_G_CROP ioctl with a pointer to this + structure. The driver fills the members of the rect + field or returns &EINVAL; if the input arguments are invalid, or if cropping + is not supported on the given pad. + + To change the current crop rectangle applications set both the + pad and which fields + and all members of the rect field. They then call + the VIDIOC_SUBDEV_S_CROP ioctl with a pointer to this + structure. The driver verifies the requested crop rectangle, adjusts it + based on the hardware capabilities and configures the device. Upon return + the &v4l2-subdev-crop; contains the current format as would be returned + by a VIDIOC_SUBDEV_G_CROP call. + + Applications can query the device capabilities by setting the + which to + V4L2_SUBDEV_FORMAT_TRY. When set, 'try' crop + rectangles are not applied to the device by the driver, but are mangled + exactly as active crop rectangles and stored in the sub-device file handle. + Two applications querying the same sub-device would thus not interact with + each other. + + Drivers must not return an error solely because the requested crop + rectangle doesn't match the device capabilities. They must instead modify + the rectangle to match what the hardware can provide. The modified format + should be as close as possible to the original request. + + + struct <structname>v4l2_subdev_crop</structname> + + &cs-str; + + + __u32 + pad + Pad number as reported by the media framework. + + + __u32 + which + Crop rectangle to get or set, from + &v4l2-subdev-format-whence;. + + + &v4l2-rect; + rect + Crop rectangle boundaries, in pixels. + + + __u32 + reserved[8] + Reserved for future extensions. Applications and drivers must + set the array to zero. + + + +
+ + + + &return-value; + + + + EBUSY + + The crop rectangle can't be changed because the pad is currently + busy. This can be caused, for instance, by an active video stream on + the pad. The ioctl must not be retried without performing another + action to fix the problem first. Only returned by + VIDIOC_SUBDEV_S_CROP + + + + EINVAL + + The &v4l2-subdev-crop; pad + references a non-existing pad, the which + field references a non-existing format, or cropping is not supported + on the given subdev pad. + + + + + -- cgit v1.2.3