Re: [codec] [Matroska-devel] Opus in Matroksa Cont.

"Timothy B. Terriberry" <tterribe@xiph.org> Fri, 05 July 2013 19:34 UTC

Return-Path: <tterribe@xiph.org>
X-Original-To: codec@ietfa.amsl.com
Delivered-To: codec@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8C90721F99F4 for <codec@ietfa.amsl.com>; Fri, 5 Jul 2013 12:34:45 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.188
X-Spam-Level:
X-Spam-Status: No, score=-1.188 tagged_above=-999 required=5 tests=[BAYES_05=-1.11, HELO_MISMATCH_ORG=0.611, HOST_MISMATCH_COM=0.311, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Z09v5QlWLis0 for <codec@ietfa.amsl.com>; Fri, 5 Jul 2013 12:34:40 -0700 (PDT)
Received: from smtp.mozilla.org (mx2.corp.phx1.mozilla.com [63.245.216.70]) by ietfa.amsl.com (Postfix) with ESMTP id E985521F9A3D for <codec@ietf.org>; Fri, 5 Jul 2013 12:34:40 -0700 (PDT)
Received: from [172.17.0.5] (50-78-100-113-static.hfc.comcastbusiness.net [50.78.100.113]) (Authenticated sender: tterriberry@mozilla.com) by mx2.mail.corp.phx1.mozilla.com (Postfix) with ESMTPSA id 3AD21F213B; Fri, 5 Jul 2013 12:34:39 -0700 (PDT)
Message-ID: <51D71FCE.5040207@xiph.org>
Date: Fri, 05 Jul 2013 12:34:38 -0700
From: "Timothy B. Terriberry" <tterribe@xiph.org>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:19.0) Gecko/20100101 SeaMonkey/2.16
MIME-Version: 1.0
To: Discussion about the current and future development of Matroska <matroska-devel@lists.matroska.org>
References: <CAJGH+UvoBiFzjuPtJq1078OsZQTzmic1UT+02HV4jQ=eN=ydRw@mail.gmail.com> <CAJGH+UvnPN1vZ7Z1kHBTC8pKFLsi-ZnV8kCJWWycL9gbTOxpaA@mail.gmail.com> <CAOXsMFK41S_qdwyRxSM4jmg4yq+0-gt-m34ay4sXhQ4D=Zntcg@mail.gmail.com> <CANPayMR89p+=QjL0o3tkEEMVsScA2-H=ruD=tbaPUb8LUhjuRA@mail.gmail.com> <CAOXsMF+Awr5A7HYLLVrG1NSa1jy-Lbay_b69wfepYu9SqmPXhg@mail.gmail.com> <CANPayMQRCC86UAKNd1CuMe5orvjX5ioAXAS9Hbr4jqduqjQZug@mail.gmail.com> <CAJGH+UvbP=7wHhHL=Av0rKO6NWhSZ6KcLn4EZLsD=XqkpAV9yQ@mail.gmail.com> <CAOXsMFKCMuYaps7QmOUy5fQ-7eFut0k2cuc1QhKStboAPLqeZA@mail.gmail.com> <CAJGH+Us284VdUKP-FXZ_K+ozVvJjs9Z=FuwuZ4Hsif3pYW_8gg@mail.gmail.com> <CAOXsMFLXZVbaknO395WEM92xm+=U0ARjWrt9FR6ftq0Ef2yrig@mail.gmail.com> <CAJGH+Uv8R1BGOzxyPzN=riuHmX28eS9aJiuy+NDe7BgKfCKgCA@mail.gmail.com> <51AD158F.7040302@mozilla.com> <CAOXsMFL9rgPUtHbiXYXiKM7KpTyy3iTO8Kv-kW21twAr_qv_bw@mail.gmail.com> <CANPayMR9P3vSWoDXP5HdDvxWztTEFQ-W_HNomc_Ueiswj_J6Tw@mail.gmail.com>
In-Reply-To: <CANPayMR9P3vSWoDXP5HdDvxWztTEFQ-W_HNomc_Ueiswj_J6Tw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: codec@ietf.org
Subject: Re: [codec] [Matroska-devel] Opus in Matroksa Cont.
X-BeenThere: codec@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Codec WG <codec.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/codec>, <mailto:codec-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/codec>
List-Post: <mailto:codec@ietf.org>
List-Help: <mailto:codec-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/codec>, <mailto:codec-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 05 Jul 2013 19:34:45 -0000

Cross-posting to codec: N.B. that 
<http://www.ietf.org/about/note-well.html> applies to replies there.

Moritz Bunkus wrote:
> an audio packet corresponds to a video packet with timestamp 0. It also
> seems not so say what Opus needs it to say: that a number of samples
> have to be dropped because they're simply invalid.

Quoting from the first paragraph of Section 4.1: "Therefore, the first 
few samples produced by the decoder do not correspond to real input 
audio, but are instead composed of padding inserted by the encoder to 
compensate for this latency."

What do you think the text should say to make it clearer that "a number 
of samples have to be dropped because they're simply invalid"?