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 0B4D244ABB for ; Wed, 2 Nov 2022 21:42:34 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C99DB68BECE; Wed, 2 Nov 2022 23:42:31 +0200 (EET) Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 3ECAE68BC55 for ; Wed, 2 Nov 2022 23:42:26 +0200 (EET) Received: (Authenticated sender: michael@niedermayer.cc) by mail.gandi.net (Postfix) with ESMTPSA id 5F42020002 for ; Wed, 2 Nov 2022 21:42:25 +0000 (UTC) Date: Wed, 2 Nov 2022 22:42:24 +0100 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20221102214224.GK1814017@pb2> References: <20221102210239.1689-1-michael@niedermayer.cc> <20221102210239.1689-2-michael@niedermayer.cc> <20221102210714.GI1814017@pb2> <20221102213127.GJ1814017@pb2> MIME-Version: 1.0 In-Reply-To: <20221102213127.GJ1814017@pb2> Subject: Re: [FFmpeg-devel] [PATCH 2/2] swscale/output: Bias 16bps output calculations to improve non overflowing range for GBRP16/GBRPF32 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="===============2959346967840036037==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============2959346967840036037== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SCOJXUq1iwCn05li" Content-Disposition: inline --SCOJXUq1iwCn05li Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 02, 2022 at 10:31:27PM +0100, Michael Niedermayer wrote: > On Wed, Nov 02, 2022 at 10:16:57PM +0100, Andreas Rheinhardt wrote: > > Michael Niedermayer: > > > On Wed, Nov 02, 2022 at 10:02:39PM +0100, Michael Niedermayer wrote: > > >> Fixes: integer overflow > > >> Signed-off-by: Michael Niedermayer > > >> --- > > >> libswscale/output.c | 25 +++++++++++-------------- > > >> libswscale/x86/output.asm | 16 +++++++++++++++- > > >> 2 files changed, 26 insertions(+), 15 deletions(-) > > >=20 > > > Note, these corner case overflows could affect some of the similary > > > implemented cases that are not depth 16 too > > >=20 > > > ill fix them if issues are replicated > > >=20 > >=20 > > The checkasm-sw_gbrp runs into many overflows (when run under UBSan); > > e.g. fate.ffmpeg.org tells me of an issue in line 2289. Said line is not > > touched in your commits. >=20 > checkasm-sw_gbrp feeds random data widely outside sane ranges in. > the test certainly makes no sense for testing asm. There is no point > in matching C for widely invalid cases. Of cousre we shouldnt overflow > if any of this can be triggered with valid and real input (which probably > can be done in some cases) also to elaborate further, checkasm-sw_gbrp sets everything randomly that includes yuv2rgb matrix values and bits outside the valid input sample range and the resample filter coeffs. [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB If a bugfix only changes things apparently unrelated to the bug with no further explanation, that is a good sign that the bugfix is wrong. --SCOJXUq1iwCn05li Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCY2LkOQAKCRBhHseHBAsP q2b9AJ95ZJmsHgK/3PA0mZrpvDzutA9tHACfaRMcMKuqiFOwltALouy2Tx7ptk8= =4v9r -----END PGP SIGNATURE----- --SCOJXUq1iwCn05li-- --===============2959346967840036037== 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". --===============2959346967840036037==--