From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 Aug 2001 05:05:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 Aug 2001 05:05:00 -0400 Received: from gnu.in-berlin.de ([192.109.42.4]:2318 "EHLO gnu.in-berlin.de") by vger.kernel.org with ESMTP id ; Tue, 28 Aug 2001 05:04:49 -0400 X-Envelope-From: news@bytesex.org To: linux-kernel@vger.kernel.org Path: kraxel From: Gerd Knorr Newsgroups: lists.linux.kernel Subject: Re: v4l interface questions Date: 28 Aug 2001 07:14:12 GMT Organization: SuSE Labs, =?ISO-8859-1?Q?Au=DFenstelle?= Berlin Message-ID: In-Reply-To: <20010827231126.A21664@bug.ucw.cz> NNTP-Posting-Host: localhost X-Trace: bytesex.org 998982852 4820 127.0.0.1 (28 Aug 2001 07:14:12 GMT) User-Agent: slrn/0.9.7.0 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Pavel Machek wrote: > Hi! > > I have few questions about v4l api. > > I have device (vicam == usb 3com homeconnect camera), which would like to > fit into v4l framework. But... mmap is not really native operation for > usb. Should I emulate it, or just return unsupported and expect > applications to use read()? IHMO applications should be able to fallback to read() if mmap() doesn't work. > Similar problem is there with formats. vicam has some really strange > formats. Should I do conversion in kernel? Probably. The driver should support at least one of the standard VIDEO_PALETTE_* formats. It is fine to pick one which comes close to the native format of the camera, there is no need to support _all_ formats. > Is there some usermode program that can handle camera without mmap > ability and can support arbitrary screen sizes + 16bpp grayscale? 8bpp grayscale should be no problem with xawtv. I'd suspect you will not find any app which can deal with 16bpp, there isn't even a VIDEO_PALETTE_* #define for this ... Gerd -- Damn lot people confuse usability and eye-candy.