From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755064Ab1DZMne (ORCPT ); Tue, 26 Apr 2011 08:43:34 -0400 Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]:2804 "EHLO smtp-vbr8.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754996Ab1DZMnd (ORCPT ); Tue, 26 Apr 2011 08:43:33 -0400 X-Greylist: delayed 603 seconds by postgrey-1.27 at vger.kernel.org; Tue, 26 Apr 2011 08:43:32 EDT Message-ID: In-Reply-To: <4DB6B28D.5090607@redhat.com> References: <201104252323.20420.linux@rainbow-software.org> <201104260832.11150.hverkuil@xs4all.nl> <201104261030.21681.linux@rainbow-software.org> <4DB6B28D.5090607@redhat.com> Date: Tue, 26 Apr 2011 14:33:20 +0200 Subject: Re: [PATCH] usbvision: remove (broken) image format conversion From: "Hans Verkuil" To: "Hans de Goede" Cc: "Ondrej Zary" , "Joerg Heckenbach" , "Dwaine Garden" , linux-media@vger.kernel.org, "Kernel development list" User-Agent: SquirrelMail/1.4.18 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Hi, > > On 04/26/2011 10:30 AM, Ondrej Zary wrote: >> On Tuesday 26 April 2011, you wrote: >>> On Monday, April 25, 2011 23:23:17 Ondrej Zary wrote: >>>> The YVU420 and YUV422P formats are broken and cause kernel panic on >>>> use. >>>> (YVU420 does not work and sometimes causes "unable to handle paging >>>> request" panic, YUV422P always causes "NULL pointer dereference"). >>>> >>>> As V4L2 spec says that drivers shouldn't do any in-kernel image format >>>> conversion, remove it completely (except YUYV). >>> >>> What really should happen is that the conversion is moved to >>> libv4lconvert. >>> I've never had the time to tackle that, but it would improve this >>> driver a >>> lot. >> >> Depending on isoc_mode module parameter, the device uses different image >> formats: YUV 4:2:2 interleaved, YUV 4:2:0 planar or compressed format. >> >> Maybe the parameter should go away and these three formats exposed to >> userspace? > > That sounds right, > >> Hopefully the non-compressed formats could be used directly >> without any conversion. But the compressed format (with new >> V4L2_PIX_FMT_ >> assigned?) should be preferred (as it provides much higher frame rates). >> The >> code moved into libv4lconvert would decompress the format and convert >> into >> something standard (YUV420?). > > Correct. > >> >>> Would you perhaps be interested in doing that work? >> >> I can try it. But the hardware isn't mine so my time is limited. >> > > If you could give it a shot that would be great. I've some hardware to > test this with (although I've never actually tested that hardware), so > I can hopefully pick things up if you cannot finish things before you > need to return the hardware. I can also test this. Regards, Hans > > Thanks & Regards, > > Hans >