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 EABFE4A69C for ; Sun, 5 May 2024 01:45:13 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id D887F68D56D; Sun, 5 May 2024 04:45:10 +0300 (EEST) Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 3C14A68D48A for ; Sun, 5 May 2024 04:45:05 +0300 (EEST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 74047C0004 for ; Sun, 5 May 2024 01:45:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=niedermayer.cc; s=gm1; t=1714873504; 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=zr9rFspKvECHcQwg/B9N9kUtvwUVCS0XFpK9SFfLUtM=; b=GEjeb0LFJTXvuoZGgBDrK9sK0FKPxwbYZyvwZpYquDSyyXeCksSXqr9Vrfy/RWHCi8TD68 ajboQfkYYkVUliXdWK6MTrL4LYZu3OxK/anXGfuFDvrDvgveU3gc3zplb82FmR6H8tq01T uX0I3Yx1K3Nrzau6G3HgeuknK51lllIV/IRYoIQnF2KnyP8rusT2bFjcQOFJCtxS29JGFv f6zZDsBYvZkRmvXF3H/hwBBsLi5VY7uqddTuRmVWUKpboS/jk9wBJlxMDUx3T4BPfV9nru F33BtjdwlKH39cnZViEOtdFnb9EulhT0ODIBxio1dmkqLOe2v5na/58Gc7EjEw== Date: Sun, 5 May 2024 03:45:03 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20240505014503.GA6420@pb2> References: <20240430231926.2506728-1-michael@niedermayer.cc> <8aa7804e-ce52-48ff-8909-dc4ca98763da@gmail.com> <51cfa301-0a67-484b-a68b-0c2d5e5ea9e8@gmail.com> <20240504205857.GW6420@pb2> <83b46d22-7d4a-4b3b-a9eb-daa99a7599eb@gmail.com> MIME-Version: 1.0 In-Reply-To: <83b46d22-7d4a-4b3b-a9eb-daa99a7599eb@gmail.com> X-GND-Sasl: michael@niedermayer.cc Subject: Re: [FFmpeg-devel] [PATCH v3] avformat/framecrcenc: compute the checksum for side data 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="===============6223317026085973383==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============6223317026085973383== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="zCyRuJYnqcTOUc9i" Content-Disposition: inline --zCyRuJYnqcTOUc9i Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, May 04, 2024 at 06:02:25PM -0300, James Almer wrote: >=20 >=20 > On 5/4/2024 5:58 PM, Michael Niedermayer wrote: > > On Sat, May 04, 2024 at 12:16:00PM -0300, James Almer wrote: > > > On 5/4/2024 5:34 AM, Marton Balint wrote: > > > >=20 > > > >=20 > > > > On Thu, 2 May 2024, James Almer wrote: > > > >=20 > > > > > On 5/2/2024 6:23 PM, Marton Balint wrote: > > > > > >=20 > > > > > >=20 > > > > > > =A0On Wed, 1 May 2024, Michael Niedermayer wrote: > > > > > >=20 > > > > > > > =A0This allows detecting issues in side data related code, s= ame as what > > > > > > > =A0framecrc does for before already for packet data itself. > > > > > > >=20 > > > > > > > =A0This basically reverts c6ae560a18d67b9ddaa25a0338b7fb55e3= 312e57. > > > > > >=20 > > > > > > =A0Can you at least add an option which allows disabling dumpi= ng the side > > > > > > =A0data? Changing the format of framecrc output again and agai= n is > > > > > > not very > > > > >=20 > > > > > The framehash/framemd5 muxer is versioned, which is what you shou= ld > > > > > use if you want parseable output. > > > >=20 > > > > Okay, but then the question is that why framecrc is using different= code > > > > and options? > > >=20 > > > Originally it was framecrc (using AVAdler) and framemd5 (using AVMD5)= =2E The > > > latter was renamed/aliased to framehash and made to use the AVHash AP= I, > > > which supports all lavu hashing algorithms, and is versioned. > > > If anyone cared, framecrc could be also made into an alias of frameha= sh that > > > defaults to adler32 output, but it would result in a massive change to > > > reference files, if anything because AVHash initializes adler32 with = a 1 > > > whereas framecrc does it with a 0. > >=20 > > normally starting adler32 at 0 is bad as one could prefix by a 0 byte w= ith > > no checksum change, but given we also show the size that spcific case i= snt > > an issue > >=20 > > can we make the initial value for adler32 configureable so as to improv= e long > > term stability of checksums ? (or add a adler32_1 to AVHash) >=20 > av_hash_init() already initializes adler32 with a 1. No need to do anythi= ng > there. It's the framecrc muxer that uses adler32 with 0 as init value. i was thinking about av_hash_init() supporting a 0 init to avoid changing e= very checksum. Which would increase git repository size and make long term comparissions harder because framecrc would not be compa= rable at all. not just some extra fields that occasionally appear thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB it is not once nor twice but times without number that the same ideas make their appearance in the world. -- Aristotle --zCyRuJYnqcTOUc9i Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEKAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZjbknwAKCRBhHseHBAsP q4V+AJ9VZJPerts/l2QYXLxQFuWyZhD0pgCgkk4/XilqKErtOJVZRAh+o+S1rLw= =/FRW -----END PGP SIGNATURE----- --zCyRuJYnqcTOUc9i-- --===============6223317026085973383== 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". --===============6223317026085973383==--