Re: Problem with stereo to mono conversion
Steve Fiddle <[email protected]> Tue, 1 Jun 2021 00:54:50 +0100
| Newsgroups | gmane.comp.audio.audacity.devel |
|---|---|
| Message-ID | <CABp83eDtU9owsZ2em_b5LQJ7owSuKmPt32pzbPbJFHkV-5Szuw@mail.gmail.com> |
--===============9126974667476296278== Content-Type: multipart/alternative; boundary="0000000000009cd65005c3a8f58a" --0000000000009cd65005c3a8f58a Content-Type: text/plain; charset="UTF-8" Hi Federico, You're describing a bug in Audacity 2.4.2 (a regression against Audacity 2.3.3) which is fixed in the current version of Audacity. Steve On Tue, 1 Jun 2021 at 00:46, Federico Miyara <[email protected]> wrote: > > Dear All, > > I start with a speech stereo file recorded with an external digital > recorder at 44100 Hz, which I import into Audacity. I change the project > rate to 22050 at the left bottom corner and since I don't need the stereo > version I go to Tracks / Mix / Mix Stereo Down to Mono. When finished, the > track still declares 44100 Hz, which would be correct since I didn't change > the track sample rate, but the duration has halved and the pitch doubled. > This is weird and in my opinion shouldn't happen. > > What happens is that during the mixdown the track's sample rate is > actually reduced to the one declared as the project rate, but this is not > credited as the track sample rate shown in the track control panel. > > The only way to fix this is to change manually the track rate from the > track control panel. > > The desired behaviour is one oth these: either (1) the mixdown really > preserves the sample rate, limiting to mix two channels into one, or (2) > the mixdown includes adapting to the project rate, but clearly stating so > in the track control panel. > > I personally would prefer (1) since I'm just asking to mix two channels, > not to also change the sample rate, which is clearly an unnecessary and > time-consuming operation. I'm invoking here the principle of doing as > little harm as possible to the signal. When people request mixing down to > mono they know they will lose one channel, but they don't expect they also > will lose spectral content. If (2) is anyway preferred, then it would be > nice to issue a warning. > > Regards, > > Federico > > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Libre > de virus. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > <#m_-8861410147708111587_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > _______________________________________________ > audacity-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/audacity-devel > --0000000000009cd65005c3a8f58a Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div>Hi Federico,</div><div><br></div><div>You're desc= ribing a bug in Audacity 2.4.2 (a regression against Audacity 2.3.3) which = is fixed in the current version of Audacity.</div><div><br></div><div>Steve= <br></div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gm= ail_attr">On Tue, 1 Jun 2021 at 00:46, Federico Miyara <<a href=3D"mailt= o:[email protected]">[email protected]</a>> wrote:<br></di= v><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;borde= r-left:1px solid rgb(204,204,204);padding-left:1ex"> =20 =20 =20 <div bgcolor=3D"#FFFFFF"> <br> <font face=3D"Courier New">Dear All,<br> <br> I start with a speech stereo file recorded with an external digital recorder at 44100 Hz, which I import into Audacity. I change the project rate to 22050 at the left bottom corner and since I don't need the stereo version I go to Tracks / Mix / Mix Stereo Down to Mono. When finished, the track still declares 44100 Hz, which would be correct since I didn't change the track sample rate, but the duration has halved and the pitch doubled. This is weird and in my opinion shouldn't happen. <br> <br> What happens is that during the mixdown the track's sample rate i= s actually reduced to the one declared as the project rate, but this is not credited as the track sample rate shown in the track control panel.<br> <br> The only way to fix this is to change manually the track rate from the track control panel.<br> <br> The desired behaviour is one oth these: either (1) the mixdown really preserves the sample rate, limiting to mix two channels into one, or (2) the mixdown includes adapting to the project rate, but clearly stating so in the track control panel. <br> <br> I personally would prefer (1) since I'm just asking to mix two channels, not to also change the sample rate, which is clearly an unnecessary and time-consuming operation. I'm invoking here the principle of doing as little harm as possible to the signal. When people request mixing down to mono they know they will lose one channel, but they don't expect they also will lose spectral content. If (2) is anyway preferred, then it would be nice to issue a warning.<br> <br> Regards, <br> <br> Federico=C2=A0 <br> <br> <br> </font> <div id=3D"gmail-m_-8861410147708111587DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FD= F2"><br> <table style=3D"border-top:1px solid rgb(211,212,222)"> <tbody><tr> <td style=3D"width:55px;padding-top:18px"><a href=3D"https://www.avas= t.com/sig-email?utm_medium=3Demail&utm_source=3Dlink&utm_campaign= =3Dsig-email&utm_content=3Demailclient" target=3D"_blank"><img alt=3D""= style=3D"width: 46px; height: 29px;" width=3D"46" height=3D"29"></a></td> <td style=3D"width:470px;padding-top:17px;color:rgb(65,66,78);font-size:1= 3px;font-family:Arial,Helvetica,sans-serif;line-height:18px">Libre de virus= . <a href=3D"https://www.avast.com/sig-email?utm_medium=3Demail&utm_sou= rce=3Dlink&utm_campaign=3Dsig-email&utm_content=3Demailclient" styl= e=3D"color:rgb(68,83,234)" target=3D"_blank">www.avast.com</a> </td> </tr> </tbody></table> <a href=3D"#m_-8861410147708111587_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" wi= dth=3D"1" height=3D"1"> </a></div></div> _______________________________________________<br> audacity-devel mailing list<br> <a href=3D"mailto:[email protected]" target=3D"_blank">a= [email protected]</a><br> <a href=3D"https://lists.sourceforge.net/lists/listinfo/audacity-devel" rel= =3D"noreferrer" target=3D"_blank">https://lists.sourceforge.net/lists/listi= nfo/audacity-devel</a><br> </blockquote></div> --0000000000009cd65005c3a8f58a-- --===============9126974667476296278== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============9126974667476296278== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ audacity-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/audacity-devel --===============9126974667476296278==--