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Commit eab00a0d authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab
Browse files

[media] v4l: events: Define V4L2_EVENT_FRAME_SYNC 



Define a frame sync event to tell user space when the reception of a frame
starts.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@iki.fi>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent c9f88aa9

Documentation/DocBook/media/v4l/vidioc-dqevent.xml

+22 −0
Original line number Diff line number Diff line
@@ -86,6 +86,12 @@ 
	    <entry>Event data for event V4L2_EVENT_CTRL.

            </entry>

	  </row>

	  <row>

	    <entry></entry>

	    <entry>&v4l2-event-frame-sync;</entry>

            <entry><structfield>frame</structfield></entry>

	    <entry>Event data for event V4L2_EVENT_FRAME_SYNC.</entry>

	  </row>

	  <row>

	    <entry></entry>

	    <entry>__u8</entry>
@@ -220,6 +226,22 @@ 
      </tgroup>

    </table>



    <table frame="none" pgwide="1" id="v4l2-event-frame-sync">

      <title>struct <structname>v4l2_event_frame_sync</structname></title>

      <tgroup cols="3">

	&cs-str;

	<tbody valign="top">

	  <row>

	    <entry>__u32</entry>

	    <entry><structfield>frame_sequence</structfield></entry>

	    <entry>

	      The sequence number of the frame being received.

	    </entry>

	  </row>

	</tbody>

      </tgroup>

    </table>



    <table pgwide="1" frame="none" id="changes-flags">

      <title>Changes</title>

      <tgroup cols="3">

Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml

+16 −0
Original line number Diff line number Diff line
@@ -138,6 +138,22 @@ 
		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_PRIVATE_START</constant></entry>

	    <entry>0x08000000</entry>

include/linux/videodev2.h

+9 −3
Original line number Diff line number Diff line
@@ -2006,6 +2006,7 @@ struct v4l2_streamparm { 
#define V4L2_EVENT_VSYNC			1

#define V4L2_EVENT_EOS				2

#define V4L2_EVENT_CTRL				3

#define V4L2_EVENT_FRAME_SYNC			4

#define V4L2_EVENT_PRIVATE_START		0x08000000



/* Payload for V4L2_EVENT_VSYNC */
@@ -2032,11 +2033,16 @@ struct v4l2_event_ctrl { 
	__s32 default_value;

};



struct v4l2_event_frame_sync {

	__u32 frame_sequence;

};



struct v4l2_event {

	__u32				type;

	union {

		struct v4l2_event_vsync		vsync;

		struct v4l2_event_ctrl		ctrl;

		struct v4l2_event_frame_sync	frame_sync;

		__u8				data[64];

	} u;

	__u32				pending;