From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: Sakari Ailus <sakari.ailus@iki.fi>
Cc: linux-media@vger.kernel.org, a.hajda@samsung.com,
laurent.pinchart@ideasonboard.com, hverkuil@xs4all.nl,
kyungmin.park@samsung.com, sw0312.kim@samsung.com
Subject: Re: [PATCH RFC] V4L: Add s_rx_buffer subdev video operation
Date: Mon, 24 Sep 2012 18:51:41 +0200 [thread overview]
Message-ID: <50608F9D.40304@samsung.com> (raw)
In-Reply-To: <20120924134453.GH12025@valkosipuli.retiisi.org.uk>
Hi Sakari,
On 09/24/2012 03:44 PM, Sakari Ailus wrote:
> How about useing a separate video buffer queue for the purpose? That would
> provide a nice way to pass it to the user space where it's needed. It'd also
> play nicely together with the frame layout descriptors.
It's tempting, but doing frame synchronisation in user space in this case
would have been painful, if at all possible in reliable manner. It would
have significantly complicate applications and the drivers.
VIDIOC_STREAMON, VIDIOC_QBUF/DQBUF calls would have been at least roughly
synchronized, and applications would have to know somehow which video nodes
needs to be opened together. I guess things like that could be abstracted
in a library, but what do we really gain for such effort ?
And now I can just ask kernel for 2-planar buffers where everything is in
place..
Regards,
Sylwester
next prev parent reply other threads:[~2012-09-24 16:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 13:26 [PATCH RFC] V4L: Add s_rx_buffer subdev video operation Sylwester Nawrocki
2012-09-24 13:44 ` Sakari Ailus
2012-09-24 13:58 ` Laurent Pinchart
2012-09-24 17:05 ` Sylwester Nawrocki
2012-09-24 16:51 ` Sylwester Nawrocki [this message]
2012-09-24 18:26 ` Sakari Ailus
2012-09-25 9:48 ` Sylwester Nawrocki
2012-09-26 20:49 ` Sakari Ailus
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