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 v4l2_subdev_crop

&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.