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 BFA9F4520D for ; Thu, 12 Jan 2023 14:20:18 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id A0549689D6F; Thu, 12 Jan 2023 16:20:15 +0200 (EET) Received: from mail-vs1-f49.google.com (mail-vs1-f49.google.com [209.85.217.49]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 908C0689B11 for ; Thu, 12 Jan 2023 16:20:09 +0200 (EET) Received: by mail-vs1-f49.google.com with SMTP id 186so13873558vsz.13 for ; Thu, 12 Jan 2023 06:20:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=to:subject:message-id:date:from:references:in-reply-to:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=YxUrIyukxMyFJULVNkxVWlIV/S7HghGYvJNfXj7Wu9E=; b=qI86g35edXSn35XDR+/TVymd4RCa8rB5WpA+QlFU2E6dMlRVodXXeZ1X79dorPXSrr i0xYZXyJLjgI452wXkOjr4RnCE4jee21zQqXqzctEsh8NGQt9uILuQX75ITCpDnBb8T9 xMjSp0Raxb9yLlmpv3vi68KI1jw/k/fYrRMCPTSJEux4iTV4FuFLEdcunlFYi9esWhBx 1prz8allUfY7Rm3itIFOX3Ca6oidIQvgnnUBer5FUMIPlnKHT9u/0YFJXLGMjDGNrNCk 8Vx2ic6jmgJUibQbYeRO2IBkMqDiprFuQlMFGduXfVOfGO5/fMco08P+iPe1wCrnQ8YB Vr7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:references:in-reply-to:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YxUrIyukxMyFJULVNkxVWlIV/S7HghGYvJNfXj7Wu9E=; b=GWlNw55LbJX5yS18000smvq+TRHs+390/odsNPZuGJdlZS5y6E5TI/xE7zmzYZNqvc S0DTyzBJ4thHEdGRbL5WWIXMSw5ZS5WF9Q7T+Cxh2joZObQ4zalgOEMRRQ+9HfT6zqGu 3RhMfRooG1WEzqIQiLNRnv06TPhTpOb7SCpie4eqSMr+l03gs8OnP2gA5PPKbL9UjPwN gGJtLhl6c25CGMsqayAJIRjZxeGKNvfBbegYlIYCKBA85F9tQYSSVfFpUp1PgbKKmgtV mAYItk+6o691Yj8YZrgGoeqsO60HKURllIAs6be0iDifMxZcOR5+GtzMx8p52j03wMbd ifFw== X-Gm-Message-State: AFqh2ko3uhrfk+dFl3m2hDZ2FQVPb9h166e5HdrLKxKVo756JC4aIlHm 26rM5DH/laP+idnz8uegR3uDKrBOCKAAY8rO/xYvukIe X-Google-Smtp-Source: AMrXdXvxeFkrL8zHJKWwh7RKQG7k+GIfwIBDRruXKfh8hr5+M4s/W4n+hNWic9PfkL0XyxkYPtDyNgoCYIMYlh6FeT8= X-Received: by 2002:a05:6102:14a9:b0:3cb:b9c:4a24 with SMTP id d41-20020a05610214a900b003cb0b9c4a24mr6822774vsv.57.1673533207776; Thu, 12 Jan 2023 06:20:07 -0800 (PST) MIME-Version: 1.0 Received: by 2002:a05:612c:2428:b0:32a:5eaa:92e4 with HTTP; Thu, 12 Jan 2023 06:20:06 -0800 (PST) In-Reply-To: <20230108145210.GD35806@pb2> References: <20230105205342.GE4028235@pb2> <20230106172506.GG4028235@pb2> <20230108145210.GD35806@pb2> From: Paul B Mahol Date: Thu, 12 Jan 2023 15:20:06 +0100 Message-ID: To: FFmpeg development discussions and patches Subject: Re: [FFmpeg-devel] [PATCH] libswresample: avoid s16p internal processing format 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: On 1/8/23, Michael Niedermayer wrote: > On Fri, Jan 06, 2023 at 07:04:59PM +0100, Paul B Mahol wrote: >> On Fri, Jan 6, 2023 at 7:01 PM Paul B Mahol wrote: >> >> > >> > >> > On Fri, Jan 6, 2023 at 6:25 PM Michael Niedermayer >> > >> > wrote: >> > >> >> On Thu, Jan 05, 2023 at 11:08:25PM +0100, Paul B Mahol wrote: >> >> > On Thu, Jan 5, 2023 at 9:53 PM Michael Niedermayer < >> >> michael@niedermayer.cc> >> >> > wrote: >> >> > >> >> > > On Thu, Jan 05, 2023 at 01:44:10PM +0100, Paul B Mahol wrote: >> >> > > > Patch attached. >> >> > > >> >> > > > swresample.c | 3 ++- >> >> > > > 1 file changed, 2 insertions(+), 1 deletion(-) >> >> > > > eee7a0685b44aa867562138a2e2437ecb8844612 >> >> > > 0001-libswresample-swresample-avoid-s16p-internal-transfe.patch >> >> > > > From 9c4cd60e2dd41cf98d693c8251f4cfade0807073 Mon Sep 17 >> >> > > > 00:00:00 >> >> 2001 >> >> > > > From: Paul B Mahol >> >> > > > Date: Thu, 5 Jan 2023 13:40:12 +0100 >> >> > > > Subject: [PATCH] libswresample/swresample: avoid s16p internal >> >> transfer >> >> > > format >> >> > > > >> >> > > > Instead use float one by default for sample rate conversions. >> >> > > > The s16p internal transfer format produces visible and hearable >> >> > > > quantization artifacts. >> >> > > >> >> > > When does this occur and why? >> >> > > >> >> > >> >> > It occurs always. Just compare output with 16bit and >> >> > int32/float/double. >> >> > Look at other people report on internet. >> >> > Look at src.infinitewave.ca >> >> >> >> src.infinitewave.ca uses 32bit none of what it shows should touch the >> >> codepath >> >> you change. >> >> >> >> if we look at src.infinitewave.ca for swr we see 2 types of artifacts >> >> 1. Aliassing which is at maybe -120db with the actual signal at 0db >> >> i would like to see some evidence that a human can hear this >> >> >> > >> > For s16p<->s16p it is much lower, around -78dB thus this patch. >> > >> > Also for others and reports for swr its is lower than exact -120dB >> > >> > >> > 2. Reflection and attenuation at the transition frequency >> >> With linear filters there is a tradeof between attenuation of the >> >> passband, reflection of frequencies beyond, latency and so on >> >> You can have a perfect sharp cutoff with no attenuation and no >> >> refelection >> >> that requires a infinitly long filter. And while this looks best in >> >> this >> >> frequency plot, does it actually sound best ? If you can hear -120db >> >> signals you surely would then also hear the ringing long before a >> >> gunshot >> >> from such long filter. >> >> >> > >> One can always change linear FIR to be min phase FIR kernel. > > I certainly would welcome a wider range of filters in swr, if you want to > add > any low delay sinc approximation or in fact i would welcome any filter > you want to add. There is that afdelaysrc filter patch on ML to add FIR coefficient generation for fractional delay audio filter that can be also used as a interpolation FIR filter. And to me it seems better at same number of taps than already used/available ones in soxr and swr. Also I have done prototype of resampling filter using afir filter via custom filters in filtergraph and it operates at similar speeds like soxr (in these very non optimized approach) and providing better/wider frequency output at highest band. > > thx > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > The real ebay dictionary, page 1 > "Used only once" - "Some unspecified defect prevented a second use" > "In good condition" - "Can be repaird by experienced expert" > "As is" - "You wouldnt want it even if you were payed for it, if you knew > ..." > _______________________________________________ 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".