VIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT — Subscribe or unsubscribe event
int ioctl( | int fd, |
| int request, | |
struct v4l2_event_subscription
*argp); |
fdFile descriptor returned by open().
requestVIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT
argpSubscribe or unsubscribe V4L2 event. Subscribed events are
dequeued by using the VIDIOC_DQEVENT ioctl.
Table A.90. struct v4l2_event_subscription
| __u32 | type | Type of the event. |
| __u32 | reserved[7] | Reserved for future extensions. Drivers and applications must set the array to zero. |
Table A.91. Event Types
V4L2_EVENT_ALL | 0 | All events. V4L2_EVENT_ALL is valid only for VIDIOC_UNSUBSCRIBE_EVENT for unsubscribing all events at once. |
V4L2_EVENT_VSYNC | 1 | This event is triggered on the vertical sync. This event has struct v4l2_event_vsync associated with it. |
V4L2_EVENT_EOS | 2 | This event is triggered when the end of a stream is reached. This is typically used with MPEG decoders to report to the application when the last of the MPEG stream has been decoded. |
V4L2_EVENT_PRIVATE_START | 0x08000000 | Base event number for driver-private events. |