ioctl VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION &manvol; VIDIOC_SUBDEV_G_SELECTION VIDIOC_SUBDEV_S_SELECTION Get or set selection rectangles on a subdev pad int ioctl int fd int request struct v4l2_subdev_selection *argp Arguments fd &fd; request VIDIOC_SUBDEV_G_SELECTION, VIDIOC_SUBDEV_S_SELECTION argp Description Experimental This is an experimental interface and may change in the future. The selections are used to configure various image processing functionality performed by the subdevs which affect the image size. This currently includes cropping, scaling and composition. The selection API replaces the old subdev crop API. All the function of the crop API, and more, are supported by the selections API. See for more information on how each selection target affects the image processing pipeline inside the subdevice.
Types of selection targets There are two types of selection targets: actual and bounds. The ACTUAL targets are the targets which configure the hardware. The BOUNDS target will return a rectangle that contain all possible ACTUAL rectangles.
Discovering supported features To discover which targets are supported, the user can perform VIDIOC_SUBDEV_G_SELECTION on them. Any unsupported target will return EINVAL.
V4L2 subdev selection targets &cs-def; V4L2_SUBDEV_SEL_TGT_CROP_ACTUAL 0x0000 Actual crop. Defines the cropping performed by the processing step. V4L2_SUBDEV_SEL_TGT_CROP_BOUNDS 0x0002 Bounds of the crop rectangle. V4L2_SUBDEV_SEL_TGT_COMPOSE_ACTUAL 0x0100 Actual compose rectangle. Used to configure scaling on sink pads and composition on source pads. V4L2_SUBDEV_SEL_TGT_COMPOSE_BOUNDS 0x0102 Bounds of the compose rectangle.
V4L2 subdev selection flags &cs-def; V4L2_SUBDEV_SEL_FLAG_SIZE_GE (1 << 0) Suggest the driver it should choose greater or equal rectangle (in size) than was requested. Albeit the driver may choose a lesser size, it will only do so due to hardware limitations. Without this flag (and V4L2_SUBDEV_SEL_FLAG_SIZE_LE) the behaviour is to choose the closest possible rectangle. V4L2_SUBDEV_SEL_FLAG_SIZE_LE (1 << 1) Suggest the driver it should choose lesser or equal rectangle (in size) than was requested. Albeit the driver may choose a greater size, it will only do so due to hardware limitations. V4L2_SUBDEV_SEL_FLAG_KEEP_CONFIG (1 << 2) The configuration should not be propagated to any further processing steps. If this flag is not given, the configuration is propagated inside the subdevice to all further processing steps.
struct <structname>v4l2_subdev_selection</structname> &cs-str; __u32 which Active or try selection, from &v4l2-subdev-format-whence;. __u32 pad Pad number as reported by the media framework. __u32 target Target selection rectangle. See .. __u32 flags Flags. See . &v4l2-rect; rect Selection rectangle, in pixels. __u32 reserved[8] Reserved for future extensions. Applications and drivers must set the array to zero.
&return-value; EBUSY The selection 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_SELECTION EINVAL The &v4l2-subdev-selection; pad references a non-existing pad, the which field references a non-existing format, or the selection target is not supported on the given subdev pad.