diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml | 142 |
1 files changed, 141 insertions, 1 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml index 8b501791aa68..975f603a42ee 100644 --- a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml +++ b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml @@ -64,7 +64,19 @@ </row> <row> <entry>__u32</entry> - <entry><structfield>reserved</structfield>[7]</entry> + <entry><structfield>id</structfield></entry> + <entry>ID of the event source. If there is no ID associated with + the event source, then set this to 0. Whether or not an event + needs an ID depends on the event type.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry>Event flags, see <xref linkend="event-flags" />.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[5]</entry> <entry>Reserved for future extensions. Drivers and applications must set the array to zero.</entry> </row> @@ -100,6 +112,23 @@ </entry> </row> <row> + <entry><constant>V4L2_EVENT_CTRL</constant></entry> + <entry>3</entry> + <entry>This event requires that the <structfield>id</structfield> + matches the control ID from which you want to receive events. + This event is triggered if the control's value changes, if a + button control is pressed or if the control's flags change. + This event has &v4l2-event-ctrl; associated with it. This struct + contains much of the same information as &v4l2-queryctrl; and + &v4l2-control;. + + If the event is generated due to a call to &VIDIOC-S-CTRL; or + &VIDIOC-S-EXT-CTRLS;, then the event will not be sent to + the file handle that called the ioctl function. This prevents + nasty feedback loops. + </entry> + </row> + <row> <entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry> <entry>0x08000000</entry> <entry>Base event number for driver-private events.</entry> @@ -108,6 +137,23 @@ </tgroup> </table> + <table pgwide="1" frame="none" id="event-flags"> + <title>Event Flags</title> + <tgroup cols="3"> + &cs-def; + <tbody valign="top"> + <row> + <entry><constant>V4L2_EVENT_SUB_FL_SEND_INITIAL</constant></entry> + <entry>0x0001</entry> + <entry>When this event is subscribed an initial event will be sent + containing the current status. This only makes sense for events + that are triggered by a status change. Other events will ignore + this flag.</entry> + </row> + </tbody> + </tgroup> + </table> + <table frame="none" pgwide="1" id="v4l2-event-vsync"> <title>struct <structname>v4l2_event_vsync</structname></title> <tgroup cols="3"> @@ -122,6 +168,100 @@ </tgroup> </table> + <table frame="none" pgwide="1" id="v4l2-event-ctrl"> + <title>struct <structname>v4l2_event_ctrl</structname></title> + <tgroup cols="4"> + &cs-str; + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>changes</structfield></entry> + <entry></entry> + <entry>A bitmask that tells what has changed. See <xref linkend="changes-flags" />.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>type</structfield></entry> + <entry></entry> + <entry>The type of the control. See &v4l2-ctrl-type;.</entry> + </row> + <row> + <entry>union (anonymous)</entry> + <entry></entry> + <entry></entry> + <entry></entry> + </row> + <row> + <entry></entry> + <entry>__s32</entry> + <entry><structfield>value</structfield></entry> + <entry>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;.</entry> + </row> + <row> + <entry></entry> + <entry>__s64</entry> + <entry><structfield>value64</structfield></entry> + <entry>The 64-bit value of the control for 64-bit control types.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry></entry> + <entry>The control flags. See <xref linkend="control-flags" />.</entry> + </row> + <row> + <entry>__s32</entry> + <entry><structfield>minimum</structfield></entry> + <entry></entry> + <entry>The minimum value of the control. See &v4l2-queryctrl;.</entry> + </row> + <row> + <entry>__s32</entry> + <entry><structfield>maximum</structfield></entry> + <entry></entry> + <entry>The maximum value of the control. See &v4l2-queryctrl;.</entry> + </row> + <row> + <entry>__s32</entry> + <entry><structfield>step</structfield></entry> + <entry></entry> + <entry>The step value of the control. See &v4l2-queryctrl;.</entry> + </row> + <row> + <entry>__s32</entry> + <entry><structfield>default_value</structfield></entry> + <entry></entry> + <entry>The default value value of the control. See &v4l2-queryctrl;.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="changes-flags"> + <title>Changes</title> + <tgroup cols="3"> + &cs-def; + <tbody valign="top"> + <row> + <entry><constant>V4L2_EVENT_CTRL_CH_VALUE</constant></entry> + <entry>0x0001</entry> + <entry>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.</entry> + </row> + <row> + <entry><constant>V4L2_EVENT_CTRL_CH_FLAGS</constant></entry> + <entry>0x0002</entry> + <entry>This control event was triggered because the control flags + changed.</entry> + </row> + </tbody> + </tgroup> + </table> + </refsect1> </refentry> <!-- |