From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:59157 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751612Ab2BDLby (ORCPT ); Sat, 4 Feb 2012 06:31:54 -0500 From: Laurent Pinchart To: Sakari Ailus Cc: Sylwester Nawrocki , "linux-media@vger.kernel.org" , Guennadi Liakhovetski , "HeungJun Kim/Mobile S/W Platform Lab(DMC)/E3" , "Seung-Woo Kim/Mobile S/W Platform Lab(DMC)/E4" , Hans Verkuil Subject: Re: [Q] Interleaved formats on the media bus Date: Sat, 04 Feb 2012 12:30:08 +0100 Message-ID: <3142039.4Ht9bV5jFQ@avalon> In-Reply-To: <4F2D14ED.8080105@iki.fi> References: <4F27CF29.5090905@samsung.com> <4F2924F8.3040408@samsung.com> <4F2D14ED.8080105@iki.fi> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Sakari, On Saturday 04 February 2012 13:22:21 Sakari Ailus wrote: > Sylwester Nawrocki wrote: > > On 02/01/2012 11:00 AM, Sakari Ailus wrote: > >> I'd guess that all the ISP would do to such formats is to write them to > >> memory since I don't see much use for either in ISPs --- both typically > >> are > >> output of the ISP. > > > > Yep, correct. In fact in those cases the sensor has complicated ISP built > > in, so everything a bridge have to do is to pass data over to user space. > > > > Also non-image data might need to be passed to user space as well. > > How does one know in the user space which part of the video buffer > contains jpeg data and which part is yuv? Does the data contain some > kind of header, or how is this done currently? > > I'd be much in favour or using a separate channel ID as Guennadi asked; > that way you could quite probably save one memory copy as well. But if > the hardware already exists and behaves badly there's usually not much > you can do about it. If I'm not mistaken, the sensor doesn't send data in separate channels but interleaves them in a single channel (possibly with headers or fixed-size packets - Sylwester, could you comment on that ?). That makes it pretty difficult to do anything else than pass-through capture. -- Regards, Laurent Pinchart