ioctl VIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT
&manvol;
VIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT
Subscribe or unsubscribe event
int ioctl
int fd
int request
struct v4l2_event_subscription
*argp
Arguments
fd
&fd;
request
VIDIOC_SUBSCRIBE_EVENT, VIDIOC_UNSUBSCRIBE_EVENT
argp
Description
Subscribe or unsubscribe V4L2 event. Subscribed events are
dequeued by using the &VIDIOC-DQEVENT; ioctl.
struct v4l2_event_subscription
&cs-str;
__u32
type
Type of the event.
__u32
reserved[7]
Reserved for future extensions. Drivers and applications
must set the array to zero.
Event Types
&cs-def;
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 &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.
struct v4l2_event_vsync
&cs-str;
__u8
field
The upcoming field. See &v4l2-field;.