[media] DocBook media: improve event documentation
authorHans Verkuil <hverkuil@xs4all.nl>
Wed, 18 Mar 2015 10:05:31 +0000 (07:05 -0300)
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>
Fri, 3 Apr 2015 01:04:07 +0000 (22:04 -0300)
It always annoyed me that the event type documentation was separate from the struct
v4l2_event documentation. This patch moves it all to one place, VIDIOC_DQEVENT.

This makes much more sense.

Also changed the 'changes-flags' ref to 'ctrl-changes-flags' since this referred to
control changes. There is a src-changes-flags as well, so 'changes-flags' was a bit
vague.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Documentation/DocBook/media/v4l/compat.xml
Documentation/DocBook/media/v4l/vidioc-dqevent.xml
Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml

index 350dfb3..a0aef85 100644 (file)
@@ -2491,7 +2491,7 @@ that used it. It was originally scheduled for removal in 2.6.35.
         </listitem>
         <listitem>
          <para>Added <constant>V4L2_EVENT_CTRL_CH_RANGE</constant> control event
-         changes flag. See <xref linkend="changes-flags"/>.</para>
+         changes flag. See <xref linkend="ctrl-changes-flags"/>.</para>
         </listitem>
       </orderedlist>
     </section>
index b036f89..a31eea0 100644 (file)
@@ -64,7 +64,7 @@
            <entry>__u32</entry>
            <entry><structfield>type</structfield></entry>
             <entry></entry>
-           <entry>Type of the event.</entry>
+           <entry>Type of the event, see <xref linkend="event-type" />.</entry>
          </row>
          <row>
            <entry>union</entry>
       </tgroup>
     </table>
 
+    <table frame="none" pgwide="1" id="event-type">
+      <title>Event Types</title>
+      <tgroup cols="3">
+       &cs-def;
+       <tbody valign="top">
+         <row>
+           <entry><constant>V4L2_EVENT_ALL</constant></entry>
+           <entry>0</entry>
+           <entry>All events. V4L2_EVENT_ALL is valid only for
+           VIDIOC_UNSUBSCRIBE_EVENT for unsubscribing all events at once.
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_VSYNC</constant></entry>
+           <entry>1</entry>
+           <entry>This event is triggered on the vertical sync.
+           This event has a &v4l2-event-vsync; associated with it.
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_EOS</constant></entry>
+           <entry>2</entry>
+           <entry>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.
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_CTRL</constant></entry>
+           <entry>3</entry>
+           <entry><para>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 a &v4l2-event-ctrl; associated with it. This struct
+               contains much of the same information as &v4l2-queryctrl; and
+               &v4l2-control;.</para>
+
+               <para>If the event is generated due to a call to &VIDIOC-S-CTRL; or
+               &VIDIOC-S-EXT-CTRLS;, then the event will <emphasis>not</emphasis> be sent to
+               the file handle that called the ioctl function. This prevents
+               nasty feedback loops. If you <emphasis>do</emphasis> want to get the
+               event, then set the <constant>V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK</constant>
+               flag.
+               </para>
+
+               <para>This event type will ensure that no information is lost when
+               more events are raised than there is room internally. In that
+               case the &v4l2-event-ctrl; of the second-oldest event is kept,
+               but the <structfield>changes</structfield> field of the
+               second-oldest event is ORed with the <structfield>changes</structfield>
+               field of the oldest event.</para>
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_FRAME_SYNC</constant></entry>
+           <entry>4</entry>
+           <entry>
+             <para>Triggered immediately when the reception of a
+             frame has begun. This event has a
+             &v4l2-event-frame-sync; associated with it.</para>
+
+             <para>If the hardware needs to be stopped in the case of a
+             buffer underrun it might not be able to generate this event.
+             In such cases the <structfield>frame_sequence</structfield>
+             field in &v4l2-event-frame-sync; will not be incremented. This
+             causes two consecutive frame sequence numbers to have n times
+             frame interval in between them.</para>
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_SOURCE_CHANGE</constant></entry>
+           <entry>5</entry>
+           <entry>
+             <para>This event is triggered when a source parameter change is
+              detected during runtime by the video device. It can be a
+              runtime resolution change triggered by a video decoder or the
+              format change happening on an input connector.
+              This event requires that the <structfield>id</structfield>
+              matches the input index (when used with a video device node)
+              or the pad index (when used with a subdevice node) from which
+              you want to receive events.</para>
+
+              <para>This event has a &v4l2-event-src-change; associated
+             with it. The <structfield>changes</structfield> bitfield denotes
+             what has changed for the subscribed pad. If multiple events
+             occurred before application could dequeue them, then the changes
+             will have the ORed value of all the events generated.</para>
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_MOTION_DET</constant></entry>
+           <entry>6</entry>
+           <entry>
+             <para>Triggered whenever the motion detection state for one or more of the regions
+             changes. This event has a &v4l2-event-motion-det; associated with it.</para>
+           </entry>
+         </row>
+         <row>
+           <entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry>
+           <entry>0x08000000</entry>
+           <entry>Base event number for driver-private events.</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">
            <entry>__u32</entry>
            <entry><structfield>changes</structfield></entry>
            <entry></entry>
-           <entry>A bitmask that tells what has changed. See <xref linkend="changes-flags" />.</entry>
+           <entry>A bitmask that tells what has changed. See <xref linkend="ctrl-changes-flags" />.</entry>
          </row>
          <row>
            <entry>__u32</entry>
       </tgroup>
     </table>
 
-    <table pgwide="1" frame="none" id="changes-flags">
-      <title>Changes</title>
+    <table pgwide="1" frame="none" id="ctrl-changes-flags">
+      <title>Control Changes</title>
       <tgroup cols="3">
        &cs-def;
        <tbody valign="top">
index d7c9365..d0332f6 100644 (file)
@@ -60,7 +60,9 @@
          <row>
            <entry>__u32</entry>
            <entry><structfield>type</structfield></entry>
-           <entry>Type of the event.</entry>
+           <entry>Type of the event, see <xref linkend="event-type" />. Note that
+<constant>V4L2_EVENT_ALL</constant> can be used with VIDIOC_UNSUBSCRIBE_EVENT
+for unsubscribing all events at once.</entry>
          </row>
          <row>
            <entry>__u32</entry>
       </tgroup>
     </table>
 
-    <table frame="none" pgwide="1" id="event-type">
-      <title>Event Types</title>
-      <tgroup cols="3">
-       &cs-def;
-       <tbody valign="top">
-         <row>
-           <entry><constant>V4L2_EVENT_ALL</constant></entry>
-           <entry>0</entry>
-           <entry>All events. V4L2_EVENT_ALL is valid only for
-           VIDIOC_UNSUBSCRIBE_EVENT for unsubscribing all events at once.
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_VSYNC</constant></entry>
-           <entry>1</entry>
-           <entry>This event is triggered on the vertical sync.
-           This event has a &v4l2-event-vsync; associated with it.
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_EOS</constant></entry>
-           <entry>2</entry>
-           <entry>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.
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_CTRL</constant></entry>
-           <entry>3</entry>
-           <entry><para>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 a &v4l2-event-ctrl; associated with it. This struct
-               contains much of the same information as &v4l2-queryctrl; and
-               &v4l2-control;.</para>
-
-               <para>If the event is generated due to a call to &VIDIOC-S-CTRL; or
-               &VIDIOC-S-EXT-CTRLS;, then the event will <emphasis>not</emphasis> be sent to
-               the file handle that called the ioctl function. This prevents
-               nasty feedback loops. If you <emphasis>do</emphasis> want to get the
-               event, then set the <constant>V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK</constant>
-               flag.
-               </para>
-
-               <para>This event type will ensure that no information is lost when
-               more events are raised than there is room internally. In that
-               case the &v4l2-event-ctrl; of the second-oldest event is kept,
-               but the <structfield>changes</structfield> field of the
-               second-oldest event is ORed with the <structfield>changes</structfield>
-               field of the oldest event.</para>
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_FRAME_SYNC</constant></entry>
-           <entry>4</entry>
-           <entry>
-             <para>Triggered immediately when the reception of a
-             frame has begun. This event has a
-             &v4l2-event-frame-sync; associated with it.</para>
-
-             <para>If the hardware needs to be stopped in the case of a
-             buffer underrun it might not be able to generate this event.
-             In such cases the <structfield>frame_sequence</structfield>
-             field in &v4l2-event-frame-sync; will not be incremented. This
-             causes two consecutive frame sequence numbers to have n times
-             frame interval in between them.</para>
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_SOURCE_CHANGE</constant></entry>
-           <entry>5</entry>
-           <entry>
-             <para>This event is triggered when a source parameter change is
-              detected during runtime by the video device. It can be a
-              runtime resolution change triggered by a video decoder or the
-              format change happening on an input connector.
-              This event requires that the <structfield>id</structfield>
-              matches the input index (when used with a video device node)
-              or the pad index (when used with a subdevice node) from which
-              you want to receive events.</para>
-
-              <para>This event has a &v4l2-event-src-change; associated
-             with it. The <structfield>changes</structfield> bitfield denotes
-             what has changed for the subscribed pad. If multiple events
-             occurred before application could dequeue them, then the changes
-             will have the ORed value of all the events generated.</para>
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_MOTION_DET</constant></entry>
-           <entry>6</entry>
-           <entry>
-             <para>Triggered whenever the motion detection state for one or more of the regions
-             changes. This event has a &v4l2-event-motion-det; associated with it.</para>
-           </entry>
-         </row>
-         <row>
-           <entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry>
-           <entry>0x08000000</entry>
-           <entry>Base event number for driver-private events.</entry>
-         </row>
-       </tbody>
-      </tgroup>
-    </table>
-
     <table pgwide="1" frame="none" id="event-flags">
       <title>Event Flags</title>
       <tgroup cols="3">