VIDIOC_SUBDEV_ENUM_FRAME_SIZE — Enumerate media bus frame sizes


int ioctl(int fd,
 int request,
 struct v4l2_subdev_frame_size_enum * argp);



File descriptor returned by open().





This ioctl allows applications to enumerate all frame sizes supported by a sub-device on the given pad for the given media bus format. Supported formats can be retrieved with the VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl.

To enumerate frame sizes applications initialize the pad, which , code and index fields of the struct v4l2_subdev_mbus_code_enum and call the VIDIOC_SUBDEV_ENUM_FRAME_SIZE ioctl with a pointer to the structure. Drivers fill the minimum and maximum frame sizes or return an EINVAL error code if one of the input parameters is invalid.

Sub-devices that only support discrete frame sizes (such as most sensors) will return one or more frame sizes with identical minimum and maximum values.

Not all possible sizes in given [minimum, maximum] ranges need to be supported. For instance, a scaler that uses a fixed-point scaling ratio might not be able to produce every frame size between the minimum and maximum values. Applications must use the VIDIOC_SUBDEV_S_FMT ioctl to try the sub-device for an exact supported frame size.

Available frame sizes may depend on the current 'try' formats at other pads of the sub-device, as well as on the current active links and the current values of V4L2 controls. See VIDIOC_SUBDEV_G_FMT for more information about try formats.

Table A.103. struct v4l2_subdev_frame_size_enum

__u32indexNumber of the format in the enumeration, set by the application.
__u32padPad number as reported by the media controller API.
__u32codeThe media bus format code, as defined in the section called “Media Bus Formats”.
__u32min_widthMinimum frame width, in pixels.
__u32max_widthMaximum frame width, in pixels.
__u32min_heightMinimum frame height, in pixels.
__u32max_heightMaximum frame height, in pixels.
__u32whichFrame sizes to be enumerated, from enum v4l2_subdev_format_whence.
__u32reserved[8]Reserved for future extensions. Applications and drivers must set the array to zero.

Return Value

On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.


The struct v4l2_subdev_frame_size_enum pad references a non-existing pad, the code is invalid for the given pad or the index field is out of bounds.