From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Jan Stary Newsgroups: gmane.comp.audio.sox Subject: Re: volume extremely low when combining many files Date: Sat, 24 Sep 2016 17:41:56 +0200 Message-ID: <20160924154154.psuxcpxgis6lbs6w@www.stare.cz> References: <99482240-79ac-4767-c935-d63238eb374a@eckner.net> <1d05af1827f0efc7968990aea4b54e3e@wingsandbeaks.org.uk> <6C04A1EE-C25C-48BB-AFD9-9D8EEF08E0D1@gmail.com> <52F5EE64-C87E-4A1A-A611-565F42DC1922@gmail.com> <7a8da1cc-5e0c-9fa3-a2cf-ab3b0c588fcf@eckner.net> Reply-To: sox-users@lists.sourceforge.net NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1474731755 16039 195.159.176.226 (24 Sep 2016 15:42:35 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 24 Sep 2016 15:42:35 +0000 (UTC) User-Agent: NeoMutt/20160827 () To: sox-users@lists.sourceforge.net Original-X-From: sox-users-bounces@lists.sourceforge.net Sat Sep 24 17:42:31 2016 Return-path: Envelope-to: gcas-sox-users@gmane.org X-ACL-Warn: Mail-Followup-To: sox-users@lists.sourceforge.net Content-Disposition: inline In-Reply-To: <7a8da1cc-5e0c-9fa3-a2cf-ab3b0c588fcf@eckner.net> X-Headers-End: 1bnp5X-0007Lq-UU X-BeenThere: sox-users@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: sox-users-bounces@lists.sourceforge.net Xref: news.gmane.org gmane.comp.audio.sox:6298 Archived-At: Received: from lists.sourceforge.net ([216.34.181.88]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1bnp5m-0001ud-BV for gcas-sox-users@gmane.org; Sat, 24 Sep 2016 17:42:19 +0200 Received: from localhost ([127.0.0.1] helo=sfs-ml-4.v29.ch3.sourceforge.com) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bnp5a-00076G-Va; Sat, 24 Sep 2016 15:42:06 +0000 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bnp5Z-00076B-UU for sox-users@lists.sourceforge.net; Sat, 24 Sep 2016 15:42:05 +0000 Received: from ns.stare.cz ([79.98.77.229] helo=mx.stare.cz) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1bnp5X-0007Lq-UU for sox-users@lists.sourceforge.net; Sat, 24 Sep 2016 15:42:05 +0000 Received: from www.stare.cz (localhost [127.0.0.1]) by www.stare.cz (OpenSMTPD) with ESMTP id 85201249 for ; Sat, 24 Sep 2016 17:41:56 +0200 (CEST) On Sep 24 07:06:23, erich@eckner.net wrote: > Hi Bob, > > can you post the command you used to generate that file? > It is indeed not "silent" at the beginning: > > >sox sound77.wav -n trim 0 9 stats > > DC offset -0.000002 > Min level -0.007812 > Max level 0.007812 > Pk lev dB -42.14 > RMS lev dB -48.17 > RMS Pk dB -47.83 > RMS Tr dB -48.64 > Crest factor 2.00 > Flat factor 2.17 > Pk count 99.0k > Bit-depth 1/8 > Num samples 397k > Length s 9.000 > Scale max 1.000000 > Window s 0.050 > > However, if I do a pad: > > >sox sound77.wav test.wav pad 10 The manpage says pad { length[@position(=)] } [...] position is optional for the first and last lengths specified and if omitted correspond to the beginning and the end of the audio respectively. So if I am reading this right, you are padding with 10 seconds of silence at the beginning. Then in particular the first 9 seconds is silence: > and analyze the result, it's silent: > > > sox test.wav -n trim 0 9 stats > DC offset 0.000000 > Min level 0.000000 > Max level 0.000000 > Pk lev dB -inf > RMS lev dB -inf > RMS Pk dB -inf > RMS Tr dB -inf > Crest factor 1.00 > Flat factor 111.97 > Pk count 794k > Bit-depth 0/0 > Num samples 397k > Length s 9.000 > Scale max 1.000000 > Window s 0.050 Jan ------------------------------------------------------------------------------