From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr12.xs4all.nl ([194.109.24.32]:1793 "EHLO smtp-vbr12.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752041AbaCANnI (ORCPT ); Sat, 1 Mar 2014 08:43:08 -0500 Message-ID: <5311E3D2.6000108@xs4all.nl> Date: Sat, 01 Mar 2014 14:42:42 +0100 From: Hans Verkuil MIME-Version: 1.0 To: Sakari Ailus , linux-media@vger.kernel.org CC: k.debski@samsung.com, laurent.pinchart@ideasonboard.com Subject: Re: [PATH v6 10/10] v4l: Document timestamp buffer flag behaviour References: <1393679828-25878-1-git-send-email-sakari.ailus@iki.fi> <1393679828-25878-11-git-send-email-sakari.ailus@iki.fi> In-Reply-To: <1393679828-25878-11-git-send-email-sakari.ailus@iki.fi> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Acked-by: Hans Verkuil Regards, Hans On 03/01/2014 02:17 PM, Sakari Ailus wrote: > Timestamp buffer flags are constant at the moment. Document them so that 1) > they're always valid and 2) not changed by the drivers. This leaves room to > extend the functionality later on if needed. > > Signed-off-by: Sakari Ailus > --- > Documentation/DocBook/media/v4l/io.xml | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > index d44401c..1bffb1c 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -653,6 +653,20 @@ plane, are stored in struct v4l2_plane instead. > In that case, struct v4l2_buffer contains an array of > plane structures. > > + Dequeued video buffers come with timestamps. The driver > + decides at which part of the frame and with which clock the > + timestamp is taken. Please see flags in the masks > + V4L2_BUF_FLAG_TIMESTAMP_MASK and > + V4L2_BUF_FLAG_TSTAMP_SRC_MASK in + linkend="buffer-flags">. These flags are always valid and constant > + across all buffers during the whole video stream. Changes in these > + flags may take place as a side effect of &VIDIOC-S-INPUT; or > + &VIDIOC-S-OUTPUT; however. The > + V4L2_BUF_FLAG_TIMESTAMP_COPY timestamp type > + which is used by e.g. on mem-to-mem devices is an exception to the > + rule: the timestamp source flags are copied from the OUTPUT video > + buffer to the CAPTURE video buffer. > + > > struct <structname>v4l2_buffer</structname> > >