From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 2679F4705B for ; Wed, 25 Oct 2023 20:56:04 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 74CAC68CAD7; Wed, 25 Oct 2023 23:56:01 +0300 (EEST) Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 1EAEA68C1DF for ; Wed, 25 Oct 2023 23:55:55 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 01C801C0005 for ; Wed, 25 Oct 2023 20:55:53 +0000 (UTC) Date: Wed, 25 Oct 2023 22:55:53 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20231025205553.GG3543730@pb2> References: <259cfc93-3e34-4081-8640-82890edbf76a@jkqxz.net> MIME-Version: 1.0 In-Reply-To: <259cfc93-3e34-4081-8640-82890edbf76a@jkqxz.net> X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] [PATCH] cbs_av1: Reject thirty-two zero bits in uvlc code X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: multipart/mixed; boundary="===============5418751926690265523==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============5418751926690265523== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dtg9VSBlHkyY0HCX" Content-Disposition: inline --dtg9VSBlHkyY0HCX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Oct 22, 2023 at 07:35:52PM +0100, Mark Thompson wrote: > The spec allows at least thirty-two zero bits followed by a one to mean > 2^32-1, with no constraint on the number of zeroes. The libaom > reference decoder does not match this, instead reading thirty-two zeroes > but not the following one to mean 2^32-1. These two interpretations are > incompatible and other implementations may follow one or the other. > Therefore reject thirty-two zeroes because the intended behaviour is not > clear. > --- > libaom, dav1d and SVT-AV1 all have the same nonstandard behaviour of stop= ping at thirty-two zeroes and not reading the one. gav1 just rejects thirt= y-two zeroes. I would suggest to contact the authors of the spec to bring this discrepancy to their attention, unless this is already known and unless this sequence is declared invalid by some other part of the spec (which would make the discrepancy only occur in invalid sequences) thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Those who are best at talking, realize last or never when they are wrong. --dtg9VSBlHkyY0HCX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZTmA1QAKCRBhHseHBAsP q4SFAKCOKRH1tcWkAqn5QQ5mJinUmCeTtgCfSHUS7LDK8MgV1NGX/UjIGPfarFg= =siJ/ -----END PGP SIGNATURE----- --dtg9VSBlHkyY0HCX-- --===============5418751926690265523== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe". --===============5418751926690265523==--