From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750732AbWFPLn4 (ORCPT ); Fri, 16 Jun 2006 07:43:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751251AbWFPLn4 (ORCPT ); Fri, 16 Jun 2006 07:43:56 -0400 Received: from ip57.73.1311O-CUD12K-02.ish.de ([62.143.73.57]:48306 "EHLO mocm.de") by vger.kernel.org with ESMTP id S1750732AbWFPLny (ORCPT ); Fri, 16 Jun 2006 07:43:54 -0400 From: Marcus Metzler MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17554.39454.563004.916138@mocm.de> Date: Fri, 16 Jun 2006 13:46:38 +0200 To: "Salvatore Sanfilippo" Cc: linux-kernel@vger.kernel.org Subject: v4l device in userspace In-Reply-To: References: X-Mailer: VM 7.17 under 21.4 (patch 19) "Constant Variable" XEmacs Lucid Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Salvatore" == Salvatore Sanfilippo writes: Salvatore> Hello, I'm trying to implement a v4l device driver for Salvatore> symbian based smart phones. In theory it is very Salvatore> simple: Salvatore> I've a little program running in the phone, capturing Salvatore> images from the camera and sending it to the linux box Salvatore> via bluetooth. Salvatore> In the linux box side, I've a deamon capturing this Salvatore> images (via a bluetooth SP channel), and.... I've to Salvatore> pass the images to a fake v4l device driver that Salvatore> actually gets the images form userspace. Salvatore> Basically I've to pass by the kernel just for the Salvatore> interface, and not to do real kernel-side work (like to Salvatore> access to the some kind of hardware). Salvatore> So I've some questions ( thanks in advance for any Salvatore> reply). Salvatore> 1) What's the best way to pass relatively high-band Salvatore> data between the v4l fake driver and userspace? A char Salvatore> device will do the work? ioctl? Salvatore> 2) What about some way to handle ioctl directly from Salvatore> userspace? Given this support I may implement the whole Salvatore> code in userspace. And I guess there are a lot of Salvatore> other real world problems that can be handled in Salvatore> userspace given the ability to handle ioctl from there. Salvatore> If you think 2) is reasonable I may actually implement Salvatore> some simple form of generic char driver that just Salvatore> allows userspace programs to handle read/write/ioctl Salvatore> opreations, and then use this to fix my real issue. Salvatore> Thank you very much for the help, and sorry if there is Salvatore> something conceptually wrong in my questions. Sounds like you should take a look at the v4l loopback device (http://www.lavrsen.dk/twiki/bin/view/Motion/VideoFourLinuxLoopbackDevice). Otherwise it may be better to ask the question on the v4l mailing list (https://listman.redhat.com/mailman/listinfo/video4linux-list). Anyway, since you already capture the video, why do you have to pipe it through a v4l device? Marcus -- /--------------------------------------------------------------------\ | Dr. Marcus O.C. Metzler | | | mocm@metzlerbros.de | http://www.metzlerbros.de/ | \--------------------------------------------------------------------/ |>>> Quis custodiet ipsos custodes <<<|