[rtcweb] Trellis IPR status? (Re: H261/MPEG-1 video quality)

Harald Alvestrand <harald@alvestrand.no> Tue, 19 November 2013 08:00 UTC

Return-Path: <harald@alvestrand.no>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com []) by ietfa.amsl.com (Postfix) with ESMTP id EB5A61AC8F5 for <rtcweb@ietfa.amsl.com>; Tue, 19 Nov 2013 00:00:41 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -7.425
X-Spam-Status: No, score=-7.425 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.525] autolearn=ham
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id 8ZO7UHLi96PK for <rtcweb@ietfa.amsl.com>; Tue, 19 Nov 2013 00:00:39 -0800 (PST)
Received: from eikenes.alvestrand.no (eikenes.alvestrand.no []) by ietfa.amsl.com (Postfix) with ESMTP id 8F00C1AC862 for <rtcweb@ietf.org>; Tue, 19 Nov 2013 00:00:39 -0800 (PST)
Received: from localhost (localhost []) by eikenes.alvestrand.no (Postfix) with ESMTP id 8D9CF39E2CB for <rtcweb@ietf.org>; Tue, 19 Nov 2013 09:00:33 +0100 (CET)
X-Virus-Scanned: Debian amavisd-new at eikenes.alvestrand.no
Received: from eikenes.alvestrand.no ([]) by localhost (eikenes.alvestrand.no []) (amavisd-new, port 10024) with ESMTP id 1yqLggbtsBcf for <rtcweb@ietf.org>; Tue, 19 Nov 2013 09:00:32 +0100 (CET)
Received: from [] (c-58f0e555.03-217-73746f1.cust.bredbandsbolaget.se []) by eikenes.alvestrand.no (Postfix) with ESMTPSA id D9D8F39E09E for <rtcweb@ietf.org>; Tue, 19 Nov 2013 09:00:32 +0100 (CET)
Message-ID: <528B1A9F.8050601@alvestrand.no>
Date: Tue, 19 Nov 2013 09:00:31 +0100
From: Harald Alvestrand <harald@alvestrand.no>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0
MIME-Version: 1.0
To: rtcweb@ietf.org
References: <5284AB73.5030505@googlemail.com> <5285209D.7020407@googlemail.com> <CAGgHUiSROwRznKZWD4kjn8Vu7SrUVwOnHN1EJ-PTgR=WQmcxAQ@mail.gmail.com> <CAOJ7v-2najyMhcVNC8r0Sg+8xgkgDwasBSz476zA0BEpi2X5Pg@mail.gmail.com> <528559E4.3020903@nostrum.com> <5286272B.5000005@bbs.darktech.org> <CAOJ7v-3AT-5BHZAp2hvqm3Th20dk8Ec3orrj-voFMBwZroPdLA@mail.gmail.com> <DUB127-W49A2377699D81E3A1EA912E0FB0@phx.gbl> <CAOJ7v-27XiBGFT8=i=8ZyWYPP4UE64Jo41Pe_i1GAAUWfhDBuA@mail.gmail.com> <52877178.6040002@googlemail.com>
In-Reply-To: <52877178.6040002@googlemail.com>
X-Enigmail-Version: 1.6
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: [rtcweb] Trellis IPR status? (Re: H261/MPEG-1 video quality)
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb/>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 19 Nov 2013 08:00:42 -0000

On 11/16/2013 02:22 PM, Maik Merten wrote:
> I filed the ffmpeg bug regarding H.261. In a nutshell: ffmpeg
> currently crashes when enabling a certain encoder feature which turns
> out to be very useful for other codecs ("trellis quantization" - which
> basically means that coefficients to be coded are selected with the
> encoding costs in mind) for the H.261 encoder. This is a rather new
> encoder feature which pays of very nicely for other formats and should
> be applicable for H.261 as well.

Just checking: Do you know the patent status of trellis quantization?

One issue this particular WG has with codecs is that in order to have a
non-IPR-encumbered spec, we need a non-IPR-encumbered encoder too -
unlike the situation for playback-only contexts, where a
non-IPR-encumbered decoder may be enough.

Thus, people who describe a particular quality level achievable with a
non-IPR-encumbered codec would seem to have to describe a
non-IPR-encumbered encoder that can achieve that quality level, too.