From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001 From: Yuval Adam <_@yuv.al> Date: Wed, 30 Aug 2017 08:25:59 +0000 Subject: Initial file dump from open source release --- Documentation/DocBook/media/v4l/vidioc-dqevent.xml | 277 +++++++++++++++++++++ 1 file changed, 277 insertions(+) create mode 100644 Documentation/DocBook/media/v4l/vidioc-dqevent.xml (limited to 'Documentation/DocBook/media/v4l/vidioc-dqevent.xml') diff --git a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml new file mode 100644 index 00000000..89891adb --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml @@ -0,0 +1,277 @@ + + + ioctl VIDIOC_DQEVENT + &manvol; + + + + VIDIOC_DQEVENT + Dequeue event + + + + + + int ioctl + int fd + int request + struct v4l2_event +*argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_DQEVENT + + + + argp + + + + + + + + + Description + + Dequeue an event from a video device. No input is required + for this ioctl. All the fields of the &v4l2-event; structure are + filled by the driver. The file handle will also receive exceptions + which the application may get by e.g. using the select system + call. + + + struct <structname>v4l2_event</structname> + + &cs-str; + + + __u32 + type + + Type of the event. + + + union + u + + + + + + &v4l2-event-vsync; + vsync + Event data for event V4L2_EVENT_VSYNC. + + + + + &v4l2-event-ctrl; + ctrl + Event data for event V4L2_EVENT_CTRL. + + + + + &v4l2-event-frame-sync; + frame_sync + Event data for event V4L2_EVENT_FRAME_SYNC. + + + + __u8 + data[64] + Event data. Defined by the event type. The union + should be used to define easily accessible type for + events. + + + __u32 + pending + + Number of pending events excluding this one. + + + __u32 + sequence + + Event sequence number. The sequence number is + incremented for every subscribed event that takes place. + If sequence numbers are not contiguous it means that + events have been lost. + + + + struct timespec + timestamp + + Event timestamp. + + + u32 + id + + The ID associated with the event source. If the event does not + have an associated ID (this depends on the event type), then this + is 0. + + + __u32 + reserved[8] + + Reserved for future extensions. Drivers must set + the array to zero. + + + +
+ + + struct <structname>v4l2_event_vsync</structname> + + &cs-str; + + + __u8 + field + The upcoming field. See &v4l2-field;. + + + +
+ + + struct <structname>v4l2_event_ctrl</structname> + + &cs-str; + + + __u32 + changes + + A bitmask that tells what has changed. See . + + + __u32 + type + + The type of the control. See &v4l2-ctrl-type;. + + + union (anonymous) + + + + + + + __s32 + value + The 32-bit value of the control for 32-bit control types. + This is 0 for string controls since the value of a string + cannot be passed using &VIDIOC-DQEVENT;. + + + + __s64 + value64 + The 64-bit value of the control for 64-bit control types. + + + __u32 + flags + + The control flags. See . + + + __s32 + minimum + + The minimum value of the control. See &v4l2-queryctrl;. + + + __s32 + maximum + + The maximum value of the control. See &v4l2-queryctrl;. + + + __s32 + step + + The step value of the control. See &v4l2-queryctrl;. + + + __s32 + default_value + + The default value value of the control. See &v4l2-queryctrl;. + + + +
+ + + struct <structname>v4l2_event_frame_sync</structname> + + &cs-str; + + + __u32 + frame_sequence + + The sequence number of the frame being received. + + + + +
+ + + Changes + + &cs-def; + + + V4L2_EVENT_CTRL_CH_VALUE + 0x0001 + This control event was triggered because the value of the control + changed. Special case: if a button control is pressed, then this + event is sent as well, even though there is not explicit value + associated with a button control. + + + V4L2_EVENT_CTRL_CH_FLAGS + 0x0002 + This control event was triggered because the control flags + changed. + + + V4L2_EVENT_CTRL_CH_RANGE + 0x0004 + This control event was triggered because the minimum, + maximum, step or the default value of the control changed. + + + +
+ + + &return-value; + + -- cgit v1.3.1