| Message ID | 1351102583-682-1-git-send-email-sakari.ailus@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sakari, Thanks for the patch. On Wednesday 24 October 2012 21:16:20 Sakari Ailus wrote: > Define video buffer flags for different timestamp types. Everything up to > now have used either realtime clock or monotonic clock, without a way to > tell which clock the timestamp was taken from. > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > Documentation/DocBook/media/v4l/io.xml | 25 +++++++++++++++++++++++++ > include/uapi/linux/videodev2.h | 4 ++++ > 2 files changed, 29 insertions(+), 0 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/io.xml > b/Documentation/DocBook/media/v4l/io.xml index 7e2f3d7..d598f2c 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -938,6 +938,31 @@ Typically applications shall use this flag for output > buffers if the data in this buffer has not been created by the CPU but by > some DMA-capable unit, in which case caches have not been used.</entry> > </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MASK</constant></entry> > + <entry>0xe000</entry> > + <entry>Mask for timestamp types below. To test the > + timestamp type, mask out bits not belonging to timestamp > + type by performing a logical and operation with buffer > + flags and timestamp mask.</tt> </entry> > + </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN</constant></entry> > + <entry>0x0000</entry> > + <entry>Unknown timestamp type. This type is used by > + drivers before Linux 3.8 and may be either monotonic (see > + below) or realtime. Monotonic clock has been favoured in > + embedded systems whereas most of the drivers use the > + realtime clock.</entry> > + </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC</constant></entry> > + <entry>0x2000</entry> > + <entry>The buffer timestamp has been taken from the > + <constant>CLOCK_MONOTONIC</constant> clock. To access the > + same clock outside V4L2, use <tt>clock_gettime(2)</tt> > + .</entry> > + </row> > </tbody> > </tgroup> > </table> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 57bfa59..5cd8823 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -686,6 +686,10 @@ struct v4l2_buffer { > /* Cache handling flags */ > #define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0800 > #define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x1000 > +/* Timestamp type */ > +#define V4L2_BUF_FLAG_TIMESTAMP_MASK 0xe000 > +#define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x0000 > +#define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x2000 > > /* > * O V E R L A Y P R E V I E W
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 7e2f3d7..d598f2c 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -938,6 +938,31 @@ Typically applications shall use this flag for output buffers if the data in this buffer has not been created by the CPU but by some DMA-capable unit, in which case caches have not been used.</entry> </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MASK</constant></entry> + <entry>0xe000</entry> + <entry>Mask for timestamp types below. To test the + timestamp type, mask out bits not belonging to timestamp + type by performing a logical and operation with buffer + flags and timestamp mask.</tt> </entry> + </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN</constant></entry> + <entry>0x0000</entry> + <entry>Unknown timestamp type. This type is used by + drivers before Linux 3.8 and may be either monotonic (see + below) or realtime. Monotonic clock has been favoured in + embedded systems whereas most of the drivers use the + realtime clock.</entry> + </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC</constant></entry> + <entry>0x2000</entry> + <entry>The buffer timestamp has been taken from the + <constant>CLOCK_MONOTONIC</constant> clock. To access the + same clock outside V4L2, use <tt>clock_gettime(2)</tt> + .</entry> + </row> </tbody> </tgroup> </table> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 57bfa59..5cd8823 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -686,6 +686,10 @@ struct v4l2_buffer { /* Cache handling flags */ #define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0800 #define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x1000 +/* Timestamp type */ +#define V4L2_BUF_FLAG_TIMESTAMP_MASK 0xe000 +#define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x0000 +#define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x2000 /* * O V E R L A Y P R E V I E W
Define video buffer flags for different timestamp types. Everything up to now have used either realtime clock or monotonic clock, without a way to tell which clock the timestamp was taken from. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> --- Documentation/DocBook/media/v4l/io.xml | 25 +++++++++++++++++++++++++ include/uapi/linux/videodev2.h | 4 ++++ 2 files changed, 29 insertions(+), 0 deletions(-)