7.44. ioctl VIDIOC_OVERLAY¶
7.44.1. Name¶
VIDIOC_OVERLAY - Start or stop video overlay
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.