From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756329Ab1LGOBZ (ORCPT ); Wed, 7 Dec 2011 09:01:25 -0500 Received: from ffm.saftware.de ([83.141.3.46]:35735 "EHLO ffm.saftware.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755908Ab1LGOBX (ORCPT ); Wed, 7 Dec 2011 09:01:23 -0500 Message-ID: <4EDF71AE.5070509@linuxtv.org> Date: Wed, 07 Dec 2011 15:01:18 +0100 From: Andreas Oberritter User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111124 Thunderbird/8.0 MIME-Version: 1.0 To: Mark Brown CC: Mauro Carvalho Chehab , HoP , Florian Fainelli , Alan Cox , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] vtunerc: virtual DVB device - is it ok to NACK driver because of worrying about possible misusage? References: <20111202231909.1ca311e2@lxorguk.ukuu.org.uk> <4EDC9B17.2080701@gmail.com> <4EDD01BA.40208@redhat.com> <4EDD2C82.7040804@linuxtv.org> <20111206112153.GC17194@sirena.org.uk> <4EDE0427.2050307@linuxtv.org> <20111206141929.GE17731@opensource.wolfsonmicro.com> <4EDE2B3B.2080905@linuxtv.org> <20111207134848.GB18837@opensource.wolfsonmicro.com> In-Reply-To: <20111207134848.GB18837@opensource.wolfsonmicro.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07.12.2011 14:49, Mark Brown wrote: > On Tue, Dec 06, 2011 at 03:48:27PM +0100, Andreas Oberritter wrote: >> On 06.12.2011 15:19, Mark Brown wrote: > >>> Your assertatation that applications should ignore the underlying >>> transport (which seems to be a big part of what you're saying) isn't >>> entirely in line with reality. > >> Did you notice that we're talking about a very particular application? > > *sigh* > >> VoIP really is totally off-topic. The B in DVB stands for broadcast. >> There's only one direction in which MPEG payload is to be sent (using >> RTP for example). You can't just re-encode the data on the fly without >> loss of information. > > This is pretty much exactly the case for VoIP some of the time (though > obviously bidirectional use cases are rather common there's things like > conferencing). I would really expect similar considerations to apply > for video content as they certainly do in videoconferencing VoIP > applications - if the application knows about the network it can tailor > what it's doing to that network. > > For example, if it is using a network with a guaranteed bandwidth it can > assume that bandwidth. If it knows something about the structure of the > network it may be able to arrange to work around choke points. > Depending on the situation even something lossy may be the answer - if > it's the difference between working at all and not working then the cost > may be worth it. Once and for all: We have *not* discussed a generic video streaming application. It's only, I repeat, only about accessing a remote DVB API tuner *as if it was local*. No data received from a satellite, cable or terrestrial DVB network shall be modified by this application! Virtually *every* user of it will use it in a LAN. It can't be so hard to understand.