From patchwork Mon May 22 23:36:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 41787 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a05:6a20:c51c:b0:10c:5e6f:955f with SMTP id gm28csp175334pzb; Mon, 22 May 2023 16:36:52 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ7sjrlkhhFGMAz9ODqGOpnAn6t7wR8qZE1w2kkZDg5kOyAcqmhULW+pERVjT57TPOoAHxdB X-Received: by 2002:aa7:c0d5:0:b0:50b:c9d4:8804 with SMTP id j21-20020aa7c0d5000000b0050bc9d48804mr10687754edp.4.1684798612177; Mon, 22 May 2023 16:36:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1684798612; cv=none; d=google.com; s=arc-20160816; b=qaSigRjB2aq3HULfxJbcUqOdjgeY5WOqgmvGeLc0eniZ2I9vld+vRPEzELMkjGaU2H L1krKs/4PNkE+EnjSCMZp1NJnzE6H4KcMTk2LN3SRPkiQs4UqU7XTsXMCaZ6WIUZ+OGF /vVYVJ0Juq+kJagycxFC/NEFXdg4zBjM7DQT94rgV9w1j4LXj0TMXtpbfwtJ7DKk+6F1 Widm3H2pGB+K7E5yLZzPs601b+0NRUF+GbLk+iQXX4wE5n1KPnsaMCyP0+M+b+lQQOw2 XkTi6uxAe7r1yd7R1FjiyB+0qmEvoL3d5J4f6d0EHx/5vCHDYCcUtEVh6OJXi03aG6zr 0F9Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:reply-to :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:subject:references:in-reply-to:message-id:date :to:from:delivered-to; bh=I0PxEEyRtFuAoVmKlEpRr2xSKMBWAlwqGYvJmSMzKt0=; b=U63IYXbCaEhbFtj9Kv0QRUNunp4l8ru+i3SQB4CyqjwNR4iaSbHOfZ4PPr3okwOAt6 y4xc0UxLL++9BbU8NxRqtUppQ5TYajcqgRcJSncRQrRcvowg9rALTxom4A2oZofPBO5C 0Hr6qVdwg0clOLWA7WfbyFS2O9+TdXHtgaSnF+tcIHZwAu9EFjQ+BELggNMEmNc/RV3S 8SP70zRWuP6er7DAgnE6njof0kllr8x4spGwJiUqpMz97gfyd5mAjEM8+1O/wrqnpW9c qQTkIRRFNlUmv5+ZWKhKTF3/uYfQdSLPf0az5czifSAbXhV2OCJ7Q2V9fJN8OGUJ3TYQ hgmw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org. [79.124.17.100]) by mx.google.com with ESMTP id v13-20020aa7cd4d000000b0050bc9115cacsi4432599edw.293.2023.05.22.16.36.51; Mon, 22 May 2023 16:36:52 -0700 (PDT) Received-SPF: pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) client-ip=79.124.17.100; Authentication-Results: mx.google.com; spf=pass (google.com: domain of ffmpeg-devel-bounces@ffmpeg.org designates 79.124.17.100 as permitted sender) smtp.mailfrom=ffmpeg-devel-bounces@ffmpeg.org Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 588AB68C126; Tue, 23 May 2023 02:36:15 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 59F0A68C095 for ; Tue, 23 May 2023 02:36:06 +0300 (EEST) Received: (Authenticated sender: michael@niedermayer.cc) by mail.gandi.net (Postfix) with ESMTPSA id BE2D91BF205 for ; Mon, 22 May 2023 23:36:05 +0000 (UTC) From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Tue, 23 May 2023 01:36:00 +0200 Message-Id: <20230522233601.20552-5-michael@niedermayer.cc> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230522233601.20552-1-michael@niedermayer.cc> References: <20230522233601.20552-1-michael@niedermayer.cc> Subject: [FFmpeg-devel] [PATCH 5/6] avcodec/kbdwin: Avoid computing bessel values twice 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 MIME-Version: 1.0 Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" X-TUID: GU6Fmw26tkGJ Also reduce neeeded temporary storage by half Signed-off-by: Michael Niedermayer --- libavcodec/kbdwin.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/libavcodec/kbdwin.c b/libavcodec/kbdwin.c index 5dff334250..e2f6491124 100644 --- a/libavcodec/kbdwin.c +++ b/libavcodec/kbdwin.c @@ -23,23 +23,29 @@ av_cold void ff_kbd_window_init(float *window, float alpha, int n) { - int i, j; - double sum = 0.0, bessel, tmp; - double local_window[FF_KBD_WINDOW_MAX]; - double alpha2 = (alpha * M_PI / n) * (alpha * M_PI / n); + int i; + double sum = 0.0, tmp; + double scale = 0.0; + double temp[FF_KBD_WINDOW_MAX / 2 + 1]; + double alpha2 = 4 * (alpha * M_PI / n) * (alpha * M_PI / n); av_assert0(n <= FF_KBD_WINDOW_MAX); - for (i = 0; i < n; i++) { + for (i = 0; i <= n / 2; i++) { tmp = i * (n - i) * alpha2; - bessel = av_bessel_i0(sqrt(tmp) * 2); - sum += bessel; - local_window[i] = sum; + temp[i] = av_bessel_i0(sqrt(tmp)); + scale += temp[i] * (1 + (i && i