Hi Hans, Thanks for your prompt comments. On Wed, Aug 28, 2013 at 05:30:01PM +0200, Hans Verkuil wrote: > On 08/28/2013 05:24 PM, Sakari Ailus wrote: > > Some devices such as the uvc produce timestamps at the beginning of the > > frame rather than at the end of it. Add a buffer flag > > (V4L2_BUF_FLAG_TIMESTAMP_SOF) to tell about this. > > > > Also document timestamp_type in struct vb2_queue, and make the uvc set the > > buffer flag. > > > > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx> > > --- > > since v4: > > - Fixes according to Hans's comments. > > > > - Note in comment the uvc driver will set the SOF flag from now on. > > > > - Change comment of vb2_queue timestamp_type field: this is timestamp flags > > rather than just type. I stopped short of renaming the field. > > > > Documentation/DocBook/media/v4l/io.xml | 19 ++++++++++++++----- > > drivers/media/usb/uvc/uvc_queue.c | 3 ++- > > include/media/videobuf2-core.h | 1 + > > include/uapi/linux/videodev2.h | 10 ++++++++++ > > 4 files changed, 27 insertions(+), 6 deletions(-) > > > > diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > > index 2c155cc..3aee210 100644 > > --- a/Documentation/DocBook/media/v4l/io.xml > > +++ b/Documentation/DocBook/media/v4l/io.xml > > @@ -654,11 +654,12 @@ plane, are stored in struct <structname>v4l2_plane</structname> instead. > > In that case, struct <structname>v4l2_buffer</structname> contains an array of > > plane structures.</para> > > > > - <para>For timestamp types that are sampled from the system clock > > -(V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC) it is guaranteed that the timestamp is > > -taken after the complete frame has been received (or transmitted in > > -case of video output devices). For other kinds of > > -timestamps this may vary depending on the driver.</para> > > + <para>The timestamp is taken once the complete frame has been > > +received (or transmitted for output devices) unless > > unless -> unless the > > > +<constant>V4L2_BUF_FLAG_TIMESTAMP_SOF</constant> buffer flag is set. > > +If <constant>V4L2_BUF_FLAG_TIMESTAMP_SOF</constant> is set, the > > the -> then the Fixed both. > > +timestamp is taken when the first pixel of the frame is received > > +(or transmitted).</para> > > > > <table frame="none" pgwide="1" id="v4l2-buffer"> > > <title>struct <structname>v4l2_buffer</structname></title> > > @@ -1120,6 +1121,14 @@ in which case caches have not been used.</entry> > > <entry>The CAPTURE buffer timestamp has been taken from the > > corresponding OUTPUT buffer. This flag applies only to mem2mem devices.</entry> > > </row> > > + <row> > > + <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_SOF</constant></entry> > > + <entry>0x00010000</entry> > > + <entry>The buffer timestamp has been taken when the first > > I think 'has been' should be 'was' in this context. Then I wonder if I should change all the other flags, too. :-) "Has been" is consistent with the documentation of other flags. -- Cheers, Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
