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 3A4B94C26F for ; Tue, 23 Jul 2024 18:30:41 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 1D30668D54C; Tue, 23 Jul 2024 21:30:38 +0300 (EEST) Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 2BC4868D211 for ; Tue, 23 Jul 2024 21:30:31 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 7E70D40004 for ; Tue, 23 Jul 2024 18:30:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1721759430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=X21jTb9alMiIjHDzZj3ZvUGEIV9IIjJ5cYk1uJa8P3A=; b=OiZUbH5mjEuWdwWlWwI4UDILXITo1fDW4GUZGjgwFVvPlgfsMAHisJWe5Dz/241HjQhKPn RX59V/tT5JWrf4hfA8f2SYhh5HduAnvCBl7lk407IRQxFy6Yw9KfALg1bzRhthrecCedmT jo4D1go+1+XFegy1UIeFXM7VGbqy8xkndMRCEXJWIesk2QO8qsgBauN+j/W/Tq2hFMi0B5 iskioy9C57Czq72vHeMm8a8gutlw2cnsJzE5eAhVWFuyrkZBBJbFiNMBw/ZfTX3wFfkws6 WYrhorpfpJUFjTbS6phu0103cg9vZeYKZSqLtEQZTVk0LIn66U9wE9yNEsMnJQ== Date: Tue, 23 Jul 2024 20:30:29 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20240723183029.GB4991@pb2> References: <20240715144825.3652038-1-michael@niedermayer.cc> <172119856184.21847.8183623909028998274@lain.khirnov.net> <20240720000828.GK4991@pb2> <172145586236.21847.12842344042206656670@lain.khirnov.net> MIME-Version: 1.0 In-Reply-To: <172145586236.21847.12842344042206656670@lain.khirnov.net> X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] [PATCH v2] avcodec/hevc/hevcdec: Do not allow slices to depend on failed slices 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="===============9091687315562912957==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============9091687315562912957== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="x+ia+h3A4XZzeh4n" Content-Disposition: inline --x+ia+h3A4XZzeh4n Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jul 20, 2024 at 08:11:02AM +0200, Anton Khirnov wrote: > Quoting Michael Niedermayer (2024-07-20 02:08:28) > > On Wed, Jul 17, 2024 at 08:42:41AM +0200, Anton Khirnov wrote: > > > Quoting Michael Niedermayer (2024-07-15 16:48:25) > > [...] > > > > @@ -3155,8 +3156,11 @@ static int decode_slice(HEVCContext *s, cons= t H2645NAL *nal, GetBitContext *gb) > > > > int ret; > > > > =20 > > > > ret =3D hls_slice_header(&s->sh, s, gb); > > > > - if (ret < 0) > > > > + if (ret < 0) { > > > > + //The code is not capable to rewind from an error, the sta= te now is inconsistant so we cannot use it on depandant slices > > > = ^ ^ > > > = e e > > > Also I'd drop everything before the comma, why mention rewinding that= is > > > not implemented and may not be a good idea anyway. > >=20 > > It seems we disagree on some things. > > A failing function should not corrupt the state. We also dont do that > > in other cases like SPS/PPS. > > This is also unexpected, so it should be documented. >=20 > In my view, the root problem is not that the state is corrupted, but > that the independent slice segment is missing. No rewinding you can do > will conjure it out of nowhere, and it's not at all clear to me that > using some random previous slice segment's data is the right thing to > do. I think it is bad practice to leave inconsistant state and "Just not use it" because if something either now or in the future does end up using it, that could result in undeffined or unexpected behavior thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Avoid a single point of failure, be that a person or equipment. --x+ia+h3A4XZzeh4n Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEKAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZp/2xQAKCRBhHseHBAsP qylNAKCNEhTBlWo1NfGhAJ99baxsP7nR8ACfTo874nE8lzIgYxwJzxzjXiV3wJI= =8hNc -----END PGP SIGNATURE----- --x+ia+h3A4XZzeh4n-- --===============9091687315562912957== 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". --===============9091687315562912957==--