From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1RZQ6k-0005fT-Oe for garchives@archives.gentoo.org; Sat, 10 Dec 2011 16:49:07 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 9F22C21C176; Sat, 10 Dec 2011 16:48:48 +0000 (UTC) Received: from mailout-de.gmx.net (mailout-de.gmx.net [213.165.64.22]) by pigeon.gentoo.org (Postfix) with SMTP id 52D6221C0A7 for ; Sat, 10 Dec 2011 16:47:16 +0000 (UTC) Received: (qmail invoked by alias); 10 Dec 2011 16:47:15 -0000 Received: from p54850B9A.dip0.t-ipconnect.de (EHLO gmx.net) [84.133.11.154] by mail.gmx.net (mp066) with SMTP; 10 Dec 2011 17:47:15 +0100 X-Authenticated: #20088476 X-Provags-ID: V01U2FsdGVkX1/HUxg5TtrH6xiNKCtViCLO3Pu9AaOqCFNV39toZE LiY4Rfwjlub/6t Received: by gmx.net (nbSMTP-1.00) for uid 1001 Meino.Cramer@gmx.de; Sat, 10 Dec 2011 17:47:15 +0100 (CET) Date: Sat, 10 Dec 2011 17:47:14 +0100 From: meino.cramer@gmx.de To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] [OT]: Denoising software ? Message-ID: <20111210164714.GB2924@solfire> References: <20111209184623.GB3257@solfire> <20111210102304.37da1bef@acme7.acmenet> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <20111210102304.37da1bef@acme7.acmenet> User-Agent: mutt-ng/devel-r804 (Linux) X-Y-GMX-Trusted: 0 X-Archives-Salt: f06debd7-47bd-404d-ac5d-50b5cf562743 X-Archives-Hash: 7b81b861a187519ea71e51a82cf53dc4 luis jure [11-12-10 13:28]: > on 2011-12-09 at 13:55 Michael Mol wrote: >=20 > >I couldn't tell you if it's necessarily "good", but Audacity has a > >noise filter. >=20 > that's exactly what i was about to reply. >=20 > and if you want to try a CLI tool, sox provides a similar utility. >=20 > noiseprof [profile-file] > Calculate a profile of the audio for use in noise reduction. > See the description of the noisered effect for details. >=20 > noisered [profile-file [amount]] > Reduce noise in the audio signal by profiling and filtering. This > effect is moderately effective at removing consistent background > noise such as hiss or hum. To use it, first run SoX with the > noise=E2=80=90 prof effect on a section of audio that ideally woul= d contain > silence but in fact contains noise - such sections are typically > found at the beginning or the end of a recording. noiseprof will > write out a noise profile to profile-file, or to stdout if no > profile-file or if `-' is given. E.g. sox speech.wav -n trim 0 1.5 > noiseprof speech.noise-profile To actually remove the noise, run > SoX again, this time with the noisered effect; noisered will > reduce noise according to a noise profile (which was generated by > noiseprof), from profile-file, or from stdin if no profile-file or > if `-' is given. E.g. sox speech.wav cleaned.wav noisered > speech.noise-profile 0.3 How much noise should be removed is > specified by amount-a number between 0 and 1 with a default of > 0.5. Higher numbers will remove more noise but present a greater > likelihood of removing wanted components of the audio signal. > Before replacing an original recording with a noise-reduced > version, experiment with different amount values to find the > optimal one for your audio; use headphones to check that you are > happy with the results, paying particular attention to quieter > sections of the audio. >=20 > On most systems, the two stages - profiling and reduction > - can be combined using a pipe, e.g. sox noisy.wav -n > trim 0 1 noiseprof | play noisy.wav noisered >=20 > never compared the results, if you do, i for one would be very interested > in your experience.=20 >=20 > IMO, it's much better to remove noise by small amounts in successive > passes (taking a new profile each time, of course), than trying to remove > too much noise in one pass. >=20 > let us know how it went! >=20 > lj >=20 Thanks for all your replies ! :) In the net I read about audacities denoise and that it is not /that/ good. I didnt checked it myself though. At the same place "Gnome Wave Cleaner" (gwc) was recommended instead of audacities denoiser. On its homepage there is also linked a downloadable book about digital signal processing (34 chapters) which looks quite proefessional. Gwc is ... not the youngest software and development seems to have stopped. Now I trying to get this beast working under Gentoo. The alsa-problem with "snd_pcm_write" can be workarounded ;) with installing pulseaudio and playing the sound with gwc via pulseaudio instead of with alsa directly. While compiling gwc you need to enable alsa and pulseaudio with =2E/configure. When gwc is running I wll report more. See my other posting sent just before this one. Gwc is the first denoise I will try. Have a nice, denoised weekend! :) Best regards, mcc