From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ew0-f17.google.com ([209.85.219.17]:55721 "EHLO mail-ew0-f17.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753921AbZAPBUy (ORCPT ); Thu, 15 Jan 2009 20:20:54 -0500 Received: by ewy10 with SMTP id 10so1661428ewy.13 for ; Thu, 15 Jan 2009 17:20:52 -0800 (PST) From: Kyle Guinn To: Jean-Francois Moine Subject: Re: [PATCH 1/2] Add Mars-Semi MR97310A format Date: Thu, 15 Jan 2009 19:20:48 -0600 Cc: linux-media@vger.kernel.org References: <200901142059.34943.elyk03@gmail.com> <20090115124946.52779651@free.fr> In-Reply-To: <20090115124946.52779651@free.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200901151920.48666.elyk03@gmail.com> Sender: linux-media-owner@vger.kernel.org List-ID: On Thursday 15 January 2009 05:49:46 Jean-Francois Moine wrote: > On Wed, 14 Jan 2009 20:59:34 -0600 > Kyle Guinn wrote: > > Add a pixel format for the Mars-Semi MR97310A webcam controller. > > > > The MR97310A is a dual-mode webcam controller that provides > > compressed BGGR Bayer frames. The decompression algorithm for still > > images is the same as for video, and is currently implemented in > > libgphoto2. > > Hi Kyle, > > What is the difference of this pixel format from the other Bayer ones? > This is a standard BGGR Bayer format which is compressed using a vendor-specific compression algorithm, much like V4L2_PIX_FMT_PAC207. I don't believe the compression algorithm matches any of the other pixel formats. The first two pixels in the first two rows are stored as raw 8-bit values (the top-left BGGR square), but the rest is Huffman compressed. Take a look at precalc_table() and mars_decompress() in libgphoto2/camlibs/mars/mars.c for all of the details. If you recognize this as an existing pixel format, please let me know. > Also, did you ask Hans de Goede to add the decoding to the v4l library? > That is next on my TODO list. I have a patch ready to send, but I first want to make sure there are no problems with adding this pixel format. Regards, -Kyle