Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755489AbYLWKJc (ORCPT ); Tue, 23 Dec 2008 05:09:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752916AbYLWKJY (ORCPT ); Tue, 23 Dec 2008 05:09:24 -0500 Received: from ey-out-2122.google.com ([74.125.78.26]:5362 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752683AbYLWKJW (ORCPT ); Tue, 23 Dec 2008 05:09:22 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=THGnxaHc4/SSiJKq2LS5faRwPnqzaG8PCjRsaUwMTUUBs6mdaB6f0u6ItmdZxLdu9O 6GFtGALUsZAa6E1kGHpkoBG/tWPDtIpviFHhjlpbpHH/FI2yfIG6+Qtwetb2LuDWZ+As 5rgLMQdrbgno9445LD/Ei9dWVSvvHBhFroN+w= Message-ID: <4950B8C6.30309@gmail.com> Date: Tue, 23 Dec 2008 13:09:10 +0300 From: Dmitry Krivoschekov User-Agent: Thunderbird 2.0.0.9 (X11/20071114) MIME-Version: 1.0 To: Robert Schwebel CC: Guennadi Liakhovetski , linux-kernel@vger.kernel.org, linux-fbdev-devel@lists.sourceforge.net, adaplas@gmail.com, linux-arm-kernel@lists.arm.linux.org.uk, Dan Williams Subject: Re: [PATCH 2/4 v4] i.MX31: Image Processing Unit DMA and IRQ drivers References: <20081218225834.GJ20756@pengutronix.de> <20081222183753.GD1614@pengutronix.de> <20081222200337.GD9472@pengutronix.de> In-Reply-To: <20081222200337.GD9472@pengutronix.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1511 Lines: 32 Robert Schwebel wrote: > On Mon, Dec 22, 2008 at 07:37:53PM +0100, Sascha Hauer wrote: >> Another thing is the overlay framebuffer. I think it's mainly useful >> to display video streams. > > Right. The idea is that you can push a video stream into /dev/fb1 (for > example by using the gstreamer fbdev sink) while displaying widgets from > a GUI toolkit on /dev/fb0. > >> Maybe it's better to implement this as a v4l device as unlike the >> framebuffer API the v4l API is designed to handle different image >> buffers. > > Huh? v4l is image-frames-to-userspace, not vice versa. > ...and vice versa too, v4l2 is not about input devices only but it is also related to output devices, v4l2 spec even has a special chapter dedicated to overlays [1]. Moreover, you can find such a driver within Freescale's BSP [2]. Another example is Omap's videoout driver [3]. Dmitry [1]http://v4l2spec.bytesex.org/spec-single/v4l2.html#OVERLAY [2]http://opensource.freescale.com/git?p=linux-2.6-mx.git;a=blob;f=drivers/media/video/mxc/output/mxc_v4l2_output.c;h=309700bb9d1f3b3f9dcac8a48a16d0775b8ed93a;hb=refs/heads/bsp-imx31ads-rel5 [3]http://git.omapzoom.org/?p=omapkernel.git;a=blob;f=drivers/media/video/omap/omap24xxvout.c;h=25ac1319bae58751cd1a543aa0f320159e10a475;hb=HEAD -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/