From patchwork Mon May 22 23:35:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 41785 Delivered-To: ffmpegpatchwork2@gmail.com Received: by 2002:a05:6a20:c51c:b0:10c:5e6f:955f with SMTP id gm28csp175218pzb; Mon, 22 May 2023 16:36:33 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6+kVoPbFKmrSGXew8kp+qmD3yE2ZHvC88kS1QjI9/j+fXDbBAyzz5i+oXGpeyz4SYnvS+k X-Received: by 2002:a17:907:7288:b0:957:28b2:560a with SMTP id dt8-20020a170907728800b0095728b2560amr11551763ejc.46.1684798593754; Mon, 22 May 2023 16:36:33 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1684798593; cv=none; d=google.com; s=arc-20160816; b=wVBQFdv5hEPrIkfhGRe3biC8qOMrQNcIurPd3RBNu/g6DeofTDrxnjsnKE+I3En1nX 0PemwSUI32Etl0PMgpqIpsLvjMqJAA+NfbZP+XHiBZm2NKXVNuSBCV1oI2zaX1btJVDH 0hFnkTvONL20yx6sPhjWBATXa1yso1UcmlDyZ7M3yM53gxiZsBFtnIJSE9GtUB/ZSqCf p+K4GCUpolS5K2hmuenXcuauzkj+v++4a54FweWQPDkD8ob04LZy5GfpBrS21PZUqcSc EHd2heTQcdfPg8vKxUq/IpQrUmuzCYsy59KSIkI/eOuuhuUQeuv6ps7gPLn0TuIleXgN ovvg== 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=dK7XfbePb7o461ctFqJ2xGxAwvUTCRtYItdslEibZ1g=; b=BhC1Z7RzgWYh0FrjtLXMDODMQu+fxfjt8/eivn+fchWLRZVIzs6KolyFeokG4j+71m q1wh4pcFppIRH9SYvdAlUJXQ5wc1lBeqrHt89j9ICbzaFyHamupRiDe7rl2Kd6Y8EtZn Q/wK+UKpuZscOprjLMv3pBiUqOJn6qWqQPJwXY+rpER7Oy75O6doQI2qCi1/HtNCCQwZ Gj5kBUBOXhO34pxiSvBXyw4Kx8oz26x+CAJc5zIDQpX35lsGCyBSmSTuxKKq/2s/OSbP XtNtI39qSbgxsGKSCRregqVHb8XY+ENWMbfXW4+TQmxDQHi5ag+9wvQxoqgYjqzA+AbV 3OZw== 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 n8-20020aa7c448000000b00506bd4fba2asi5363908edr.319.2023.05.22.16.36.33; Mon, 22 May 2023 16:36:33 -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 5FA3868C11D; Tue, 23 May 2023 02:36:13 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id CE40868C0B9 for ; Tue, 23 May 2023 02:36:04 +0300 (EEST) Received: (Authenticated sender: michael@niedermayer.cc) by mail.gandi.net (Postfix) with ESMTPSA id 185A1FF804 for ; Mon, 22 May 2023 23:36:03 +0000 (UTC) From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Tue, 23 May 2023 01:35:58 +0200 Message-Id: <20230522233601.20552-3-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 3/6] avfilter/window_func: Use av_bessel_i0() 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: ZUAPTxqGSQck Old code needed about 6 times as long as new with defaults in afftfilt Signed-off-by: Michael Niedermayer --- libavfilter/window_func.h | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/libavfilter/window_func.h b/libavfilter/window_func.h index 02b5def9dd..13236d8593 100644 --- a/libavfilter/window_func.h +++ b/libavfilter/window_func.h @@ -25,6 +25,7 @@ #include #include "libavutil/avassert.h" #include "libavutil/common.h" +#include "libavutil/timer.h" enum WindowFunc { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN, WFUNC_BARTLETT, WFUNC_WELCH, WFUNC_FLATTOP, @@ -59,19 +60,6 @@ enum WindowFunc { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN, { "bohman", "Bohman", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BOHMAN}, 0, 0, flag, "win_func" }, \ { "kaiser", "Kaiser", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_KAISER}, 0, 0, flag, "win_func" } -static inline double get_i0(double x) -{ - double y = 1.0, prev = 1.0, i = 1.0; - - while (fabs(prev) > 1e-20) { - double summand = prev * x * x / (4 * i * i); - y += summand; - prev = summand; - i++; - } - - return y; -} static inline void generate_window_func(float *lut, int N, int win_func, float *overlap) @@ -232,13 +220,15 @@ static inline void generate_window_func(float *lut, int N, int win_func, *overlap = 0.75; break; case WFUNC_KAISER: + { + double scale = 1.0 / av_bessel_i0(12.); for (n = 0; n < N; n++) { double x = 2.0 / (double)(N - 1); - - lut[n] = get_i0(12. * sqrt(1. - SQR(n * x - 1.))) / get_i0(12.); + lut[n] = av_bessel_i0(12. * sqrt(1. - SQR(n * x - 1.))) * scale; } *overlap = 0.75; break; + } default: av_assert0(0); }