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 DB03642F71 for ; Sat, 16 Jul 2022 12:30:34 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id E44B768B863; Sat, 16 Jul 2022 15:30:31 +0300 (EEST) Received: from mail8.parnet.fi (mail8.parnet.fi [77.234.108.134]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 3CCA768B761 for ; Sat, 16 Jul 2022 15:30:25 +0300 (EEST) Received: from mail9.parnet.fi (mail9.parnet.fi [77.234.108.21]) by mail8.parnet.fi with ESMTP id 26GCUOCb026903-26GCUOCc026903 for ; Sat, 16 Jul 2022 15:30:24 +0300 Received: from foo.martin.st (host-97-187.parnet.fi [77.234.97.187]) by mail9.parnet.fi (Postfix) with ESMTPS id 577DCA150B for ; Sat, 16 Jul 2022 15:30:24 +0300 (EEST) Date: Sat, 16 Jul 2022 15:30:23 +0300 (EEST) From: =?ISO-8859-15?Q?Martin_Storsj=F6?= To: FFmpeg development discussions and patches In-Reply-To: <20220716112336.GH2088045@pb2> Message-ID: References: <20220713204854.3114817-1-martin@martin.st> <20220713204854.3114817-5-martin@martin.st> <8E07A574-9F34-48B1-98BC-95A5B676A458@amazon.com> <3a7cff5-7691-e8cd-55c6-28f7f63cda27@martin.st> <20220715211948.GF2088045@pb2> <37f78b5-e37b-b71d-f8b6-236e47b3b9c@martin.st> <20220716112336.GH2088045@pb2> MIME-Version: 1.0 X-FE-Policy-ID: 3:14:2:SYSTEM X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: Re: [FFmpeg-devel] [PATCH 5/5] aarch64: me_cmp: Don't do uaddlv once per iteration 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-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Sat, 16 Jul 2022, Michael Niedermayer wrote: > On Sat, Jul 16, 2022 at 12:25:37AM +0300, Martin Storsj=F6 wrote: >> On Fri, 15 Jul 2022, Michael Niedermayer wrote: >> >>> On Fri, Jul 15, 2022 at 10:56:03PM +0300, Martin Storsj=F6 wrote: >>>> On Fri, 15 Jul 2022, Swinney, Jonathan wrote: >>>> >>>>> If the max height is just 16, then this should be fine. I assumed tha= t h >>>>> could have a much higher value (>1024), but if that is not the case, >>>>> then this is a useful optimization. >>>> >>>> At least according to the me_cmp.h header, which says: >>>> >>>> /* Motion estimation: >>>> * h is limited to { width / 2, width, 2 * width }, >>>> * but never larger than 16 and never smaller than 2. >>>> * Although currently h < 4 is not used as functions with >>>> * width < 8 are neither used nor implemented. */ >>> >>> These rules where written with support for encoding of all >>> standard formats in mind at the time that was written. >>> today it may make sense to extend these rules to cover the >>> things which where created since then >> >> Right, but if that suddenly changes, such a change also must expect that= it >> might need updates to all assembly implementations that implement that >> interface currently. Right now, both the defacto case (any callers in the >> codebase) and the explicit documentation says that it can't be called wi= th >> parameters outside of that range. > > What i meant was that newly added functions should be more flexible than > these old rules. That is 2 sets of rules > 1. What a caller ATM can do and expect to work (thats whats written there) > 2. What an implementor of new functions should make sure is supported With 2., do you mean if adding a new function into the same struct, or if = implementing the existing pix_abs[0][..] functions? If you mean new implementations of the existing function interface, you = say they "should be more flexible". How flexible must they be? Is it ok to = assume h<=3D256 for the w=3D16 functions? Gradually increasing the requirements for existing function interfaces = like you suggest is really problematic. If we want to require more of the functions, we should document it, and = extend the checkasm test to test that new requirement - which also extends = the requirement to the existing functions. If we don't have a checkasm = test for the required behaviour, we can pretty much assume it's broken, = even in new implementations. // Martin _______________________________________________ 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".