7.44. ioctl VIDIOC_OVERLAY¶

7.44.1. Name¶

VIDIOC_OVERLAY - Start or stop video overlay

7.44.2. Synopsis¶

VIDIOC_OVERLAY¶

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

7.44.3. Arguments¶

fd: File descriptor returned by open().
argp: Pointer to an integer.

7.44.4. 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.

7.44.5. 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.