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 9A5F3440D4 for ; Sun, 25 Sep 2022 07:54:46 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 3ABED68BA91; Sun, 25 Sep 2022 10:54:44 +0300 (EEST) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id EB03368B389 for ; Sun, 25 Sep 2022 10:54:37 +0300 (EEST) Received: from w3.tutanota.de (unknown [192.168.1.164]) by w4.tutanota.de (Postfix) with ESMTP id 21ED61060155 for ; Sun, 25 Sep 2022 07:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1664092476; s=s1; d=lynne.ee; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding:Content-Transfer-Encoding:Cc:Date:Date:In-Reply-To:In-Reply-To:MIME-Version:MIME-Version:Message-ID:Message-ID:Reply-To:References:References:Sender; bh=kzBlt4gcHOgs1uG4SuQHI0HWYuNOPebinO2FwSR7t9A=; b=jmySv8KDb7er8VIlHEA+nRUCRpYQ5o6BGPTfnj2YJ+pcEXy6BGUuK6J7gNyLVMO9 bYWk/W443M4Be+0+yWQVGGQNmTdUUzmpyeefdaMbFoTV5ONm4KU+A9SAuoDePALLvtf PK/KNVvMoQOI14moTuLdDoqidS4pECZ3zdFn6J3AfucinfkHXwndmbdpQwWL+2WhhoV z17c9rDwa1C+8eoXlkaTzFZ6qu9lv9JYvB15+knefPshC6AH1w96dZYBj8M5h5fukzo DHe5bdDZEzoI1lQfqSi+0jXr4OTlMcQv0wkJ/uY8/W6WqFClHsypOse1SbJOa9JcVz6 bFaMEhqANA== Date: Sun, 25 Sep 2022 09:54:36 +0200 (CEST) From: Lynne To: FFmpeg development discussions and patches Message-ID: In-Reply-To: References: <37cff64-511b-518d-769-f02c1fc7e49f@martin.st> <38345618-1535-1c53-6c28-52d0796e217@martin.st> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH 1/6] opus: convert encoder and decoder to lavu/tx 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: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Sep 24, 2022, 23:57 by dev@lynne.ee: > Sep 24, 2022, 21:40 by martin@martin.st: > >> What about ac3dsp then - that one seems like it's fairly optimized for arm? >> > Haven't touched them, they're still being used. Unfortunately, for AC3, > the full MDCT optimizations in lavc do make a difference and the overall > decoder becomes 15% slower with this patch on for aarch64 with lavu/tx's > asm disabled and 7% slower with lavu/tx's asm enabled. I do plan to write > an aarch64 MDCT NEON SIMD code in a month or so, unless someone is faster, > which should make the decoder at least 10% faster with lavu/tx. > I'd just like to add this was for the float version of the ac3 decoder. The fixed-point version is a few percent faster with the patch on an A53, and quite a bit more accurate. The lavc fixed-point FFT code also has some weird large spikes in #cycles for some transform sizes, so the figure above is an average, but the dips went from 117x realtime to 78x realtime, which on a slower CPU may be the difference between stuttering and realtime playback. On this CPU, the fixed-point version is 23% slower than the float version, but on a CPU with slower float ops, it would make more sense to pick that decoder up than the float version. The 2 decoders produce nearly identical results, minus a few rounding errors, since AC3 is inherently a fixed-point codec. The only difference are the transforms themselves, and the extra ops needed to convert the 25bit ints to floats in the float decoder. _______________________________________________ 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".