From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: YUV Framebuffer Date: Wed, 17 Oct 2007 21:45:05 +0200 (CEST) Message-ID: References: <27AAC353AE72C840926448157F375E72012B59B1@NAEX17.na.qualcomm.com> <27AAC353AE72C840926448157F375E72012B5A8F@NAEX17.na.qualcomm.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1IiEpL-00030z-Qy for linux-fbdev-devel@lists.sourceforge.net; Wed, 17 Oct 2007 12:45:11 -0700 Received: from ananke.telenet-ops.be ([195.130.137.78]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1IiEpJ-00028Q-FH for linux-fbdev-devel@lists.sourceforge.net; Wed, 17 Oct 2007 12:45:11 -0700 In-Reply-To: <27AAC353AE72C840926448157F375E72012B5A8F@NAEX17.na.qualcomm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: "Rhee, C. Joon" Cc: Linux Frame Buffer Device Development On Wed, 17 Oct 2007, Rhee, C. Joon wrote: > Interleaved means YCBCR is on the same plane in this order. > Y CB Y CR Y CB Y CR.... (TV-Out) So it's still FB_TYPE_PACKED_PIXELS. > The problem of matching Y=G, CB=B and CR=R for RGB offset is that the > pixel cannot be represented directly since CB/CR gets shared between Ys. > > So, bitsperpixel would be 16 bit and both B and R offset will be 8. Doesn't sound that bad to me, if you introduce a FB_VISUAL_YCBYCR visual. Even pixels have a Cb, odd have a Cr component. The alternative is to sets bits_per_pixel = 32, but then you get more illogical component offsets. Anyone with a better suggestion? > -----Original Message----- > From: geert@linux-m68k.org [mailto:geert@linux-m68k.org] > Sent: Tuesday, October 16, 2007 11:58 PM > To: Rhee, C. Joon > Cc: Linux Frame Buffer Device Development > Subject: Re: [Linux-fbdev-devel] YUV Framebuffer > > On Tue, 16 Oct 2007, Rhee, C. Joon wrote: > > Is it possible to create framebuffer color format in YUV (eg. YUV422 > > interleaved) and expose it through /dev/fb? > > > > What would be fb_info type? > > What do you mean with `interleaved'? > Even and odd frames are separate (interlace)? > > For YUV422, you have to add a new visual type. > > A long time ago, I used this for a non-public test project: > > #define FB_TYPE_PACKED_PIXELS_LACED 5 /* Interlaced Packed > Pixels */ > #define FB_TYPE_PACKED_PIXELS_4AREAS 6 /* 4 areas of Packed > Pixels */ > > #define FB_VISUAL_YCBCR422 6 /* YCbCr 4:2:2 */ > #define FB_VISUAL_YCBCR420 7 /* YCbCr 4:2:0 */ > > > And how about about fb_var_screeninfo.green/blue/red offset? > > Just assume red, green, and blue mean Y, U, and V? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/