From: Mauro Carvalho Chehab <mchehab@redhat.com>
To: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Devin Heitmueller <dheitmueller@kernellabs.com>,
linux-media@vger.kernel.org, srinivasa.deevi@conexant.com,
Maxime Ripard <maxime.ripard@free-electrons.com>
Subject: Re: cx231xx: DMA problem on ARM
Date: Mon, 26 Sep 2011 17:03:39 -0300 [thread overview]
Message-ID: <4E80DA9B.5000604@redhat.com> (raw)
In-Reply-To: <20110926215954.5ab059e4@skate>
Em 26-09-2011 16:59, Thomas Petazzoni escreveu:
> Hello Laurent,
>
> Le Mon, 26 Sep 2011 21:02:48 +0200,
> Laurent Pinchart <laurent.pinchart@ideasonboard.com> a écrit :
>
>> Are you using the MMAP or USERPTR capture method ? If using MMAP, can
>> you try (as a test only) to unmap the buffer before queueing it and
>> to remap it after dequeuing it ?
>
> So far, we have used VLC, Cheese, or a simple OpenCV based application
> to test the V4L2 device on our ARM platform, and I have no idea which
> capture method those are using. Is there a very simple V4L test
> application that we could use to hack the buffer unmap/remap trick
> you're suggesting as a test ?
The simplest application is the v4l2grab util:
http://git.linuxtv.org/v4l-utils.git/blob/HEAD:/contrib/test/v4l2grab.c
it uses libv4l to convert to RGB and outputs a series of ppm images. By
generating one image per frame, it is easy to check artifacts on each
image.
>
> Regards,
>
> Thomas
prev parent reply other threads:[~2011-09-26 20:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-21 11:56 cx231xx: DMA problem on ARM Thomas Petazzoni
2011-09-21 12:04 ` Devin Heitmueller
2011-09-21 19:17 ` Thomas Petazzoni
2011-09-22 14:45 ` Thomas Petazzoni
2011-09-22 15:09 ` Devin Heitmueller
2011-09-22 15:29 ` Thomas Petazzoni
2011-09-23 12:04 ` Thomas Petazzoni
2011-09-23 12:26 ` Sri Deevi
2011-09-24 18:04 ` Thomas Petazzoni
2011-09-24 2:15 ` Mauro Carvalho Chehab
2011-09-26 8:13 ` Thomas Petazzoni
2011-09-26 17:32 ` Mauro Carvalho Chehab
2011-09-26 19:02 ` Laurent Pinchart
2011-09-26 19:59 ` Thomas Petazzoni
2011-09-26 20:03 ` Mauro Carvalho Chehab [this message]
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