From: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-media@vger.kernel.org, Sakari Ailus <sakari.ailus@iki.fi>,
Hans Verkuil <hverkuil@xs4all.nl>,
remi@remlab.net, Kamil Debski <k.debski@samsung.com>
Subject: Re: [RFC] Timestamps and V4L2
Date: Thu, 27 Sep 2012 00:30:49 +0200 [thread overview]
Message-ID: <50638219.7020105@gmail.com> (raw)
In-Reply-To: <32114057.tIVjSTYujk@avalon>
Hi Laurent,
On 09/25/2012 02:35 AM, Laurent Pinchart wrote:
> Does the clock type need to be selectable for mem-to-mem devices ? Do device-
> specific timestamps make sense there ?
I'd like to clarify one thing here, i.e. if we select device-specific
timestamps how should the v4l2_buffer::timestamp field behave ?
Are these two things exclusive ? Or should v4l2_buffer::timestamp be
valid even if device-specific timestamps are enabled ?
With regards to your question, I think device-specific timestamps make
sense for mem-to-mem devices. Maybe not for the very simple ones, that
process buffers 1-to-1, but codecs may need it. I was told the Exynos/
S5P Multi Format Codec device has some register the timestamps could
be read from, but it's currently not used by the s5p-mfc driver. Kamil
might provide more details on that.
I guess if capture and output devices can have their timestamping clocks
selectable it should be also possible for mem-to-mem devices.
--
Regards,
Sylwester
next prev parent reply other threads:[~2012-09-26 22:30 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 20:21 [RFC] Timestamps and V4L2 Sakari Ailus
2012-09-20 21:08 ` Rémi Denis-Courmont
2012-09-21 8:47 ` Christian Gmeiner
2012-09-21 9:33 ` Hans Verkuil
2012-09-22 12:38 ` Sakari Ailus
2012-09-22 17:12 ` Sylwester Nawrocki
2012-09-22 20:28 ` Daniel Glöckner
2012-09-23 18:40 ` Sylwester Nawrocki
2012-09-25 0:35 ` Laurent Pinchart
[not found] ` <5061DAE3.2080808@samsung.com>
2012-09-25 17:17 ` Kamil Debski
2012-09-26 22:30 ` Sylwester Nawrocki [this message]
2012-09-27 10:41 ` Laurent Pinchart
2012-09-23 11:43 ` Sakari Ailus
2012-09-24 20:11 ` Rémi Denis-Courmont
2012-09-25 6:50 ` Hans Verkuil
2012-09-25 0:34 ` Laurent Pinchart
2012-09-25 22:48 ` Sylwester Nawrocki
2012-09-23 9:18 ` Hans Verkuil
2012-09-23 13:07 ` Sakari Ailus
2012-09-24 8:30 ` Hans Verkuil
2012-09-25 0:21 ` Laurent Pinchart
2012-09-24 23:42 ` Laurent Pinchart
2012-09-25 0:00 ` Laurent Pinchart
2012-09-25 6:47 ` Hans Verkuil
2012-09-25 10:48 ` Laurent Pinchart
2012-09-25 10:54 ` Hans Verkuil
2012-09-25 11:09 ` Laurent Pinchart
2012-09-25 20:12 ` Sakari Ailus
2012-09-26 9:13 ` Laurent Pinchart
2012-09-26 19:17 ` Sakari Ailus
2012-09-27 10:55 ` Laurent Pinchart
2012-09-25 20:05 ` Sakari Ailus
2012-10-15 16:05 ` Sakari Ailus
2012-10-15 18:45 ` Laurent Pinchart
2012-10-15 18:53 ` Chris MacGregor
2012-10-15 19:59 ` Sakari Ailus
2012-10-15 20:10 ` Rémi Denis-Courmont
2012-10-16 1:25 ` Chris MacGregor
2012-10-25 0:47 ` Laurent Pinchart
2012-10-16 6:13 ` Hans Verkuil
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