From: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
To: "Ivan T. Ivanov" <iivanov@mm-sol.com>
Cc: "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Hans Verkuil <hverkuil@xs4all.nl>,
"Zutshi Vimarsh (Nokia-D-MSW/Helsinki)"
<vimarsh.zutshi@nokia.com>,
Cohen David Abraham <david.cohen@nokia.com>,
Guru Raj <gururaj.nagendra@intel.com>,
Mike Krufky <mkrufky@linuxtv.org>,
Devin Heitmueller <dheitmueller@kernellabs.com>,
Mauro Carvalho Chehab <mchehab@infradead.org>
Subject: Re: [RFC] Video events, version 2.2
Date: Sun, 25 Oct 2009 00:56:24 +0300 [thread overview]
Message-ID: <4AE37808.6090107@maxwell.research.nokia.com> (raw)
In-Reply-To: <1256302779.10472.45.camel@iivanov.int.mm-sol.com>
Ivan T. Ivanov wrote:
> Hi Sakari,
Hi,
> On Fri, 2009-10-23 at 13:18 +0300, Sakari Ailus wrote:
[clip]
>> struct v4l2_event {
>> __u32 count;
>> __u32 type;
>> __u32 sequence;
>> struct timeval timestamp;
>
> Can we use 'struct timespec' here. This will force actual
> implementation to use high-resolution source if possible,
> and remove hundreds gettimeofday() in user space, which
> should be used for event synchronization, with more
> power friendly clock_getres(CLOCK_MONOTONIC).
Good point. I originally picked timeval since it was used in
v4l2_buffer. The spec tells to use gettimeofday() for system time but
clock skewing is causes problems in video encoding.
clock_getres(CLOCK_MONOTONIC) is free of clock skewing and thus should
be more suitable for this kind of use.
I also propose to use timespec instead of timeval.
--
Sakari Ailus
sakari.ailus@maxwell.research.nokia.com
next prev parent reply other threads:[~2009-10-24 21:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-23 10:18 [RFC] Video events, version 2.2 Sakari Ailus
2009-10-23 12:59 ` Ivan T. Ivanov
2009-10-24 21:56 ` Sakari Ailus [this message]
2009-11-11 7:19 ` Hans Verkuil
2009-11-11 17:29 ` Sakari Ailus
2009-11-11 17:59 ` Hans Verkuil
2009-11-13 15:29 ` Mauro Carvalho Chehab
2009-11-13 16:00 ` Hans Verkuil
2009-11-13 17:30 ` Eino-Ville Talvala
2009-11-13 19:05 ` Sakari Ailus
2009-11-14 20:11 ` Eino-Ville Talvala
2009-11-13 17:44 ` Sakari Ailus
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