8.44. ioctl VIDIOC_OVERLAY

8.44.1. Name

VIDIOC_OVERLAY - Start or stop video overlay

8.44.2. Synopsis

int ioctl(int fd, VIDIOC_OVERLAY, const int *argp)

8.44.3. Arguments

fd

File descriptor returned by open().

argp

8.44.4. Description

This ioctl is part of the video overlay I/O method. Applications call ioctl VIDIOC_OVERLAY to start or stop the overlay. It takes a pointer to an integer which must be set to zero by the application to stop overlay, to one to start.

Drivers do not support ioctl VIDIOC_STREAMON, VIDIOC_STREAMOFF or VIDIOC_STREAMOFF with V4L2_BUF_TYPE_VIDEO_OVERLAY.

8.44.5. 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.

EINVAL

The overlay parameters have not been set up. See Video Overlay Interface for the necessary steps.