Re: perceptual audio codecs (James Johnston )


Subject: Re: perceptual audio codecs
From:    James Johnston  <audioskeptic@xxxxxxxx>
Date:    Sat, 12 Apr 2014 08:25:19 -0700
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

--047d7b342d30db878204f6da0e9a Content-Type: text/plain; charset=ISO-8859-1 I have to ask: Is this OFFICIAL source code the best known encoder? You can also get reference models for later MPEG systems, but the question remains there, as well. On Sat, Apr 12, 2014 at 12:09 AM, Joachim Thiemann < joachim.thiemann@xxxxxxxx> wrote: > Hello again Alberto, > > I just want to point out that you can get _official_ source code for > two low-bitrate audio codecs: AMR-WB+ and EnAAC+, from the 3GPP > standards body. They are very descriptively titled TS26.304 and > TS26.410 (for AMR-WB+ and Enhanced aacPlus respectively), and can be > downloaded from http://www.3gpp.org/DynaReport/26-series.htm. There > are fixed-point versions as well, but the float versions are far more > understandable. > > Enhanced aacPlus - if my memory still somewhat right from 10 years ago > - is basically AAC tuned for low bitrate, with bandwidth extension and > parametric stereo. > > AMR-WB+ is a dual-mode LP-based codec, switching between CELP and a > transform to code the residual, also with bandwidth extension and > parametric stereo. > > If you look around on the 3GPP website you can also find the source > for the ancestors of AMR-WB+ (named, well, AMR and AMR-WB). Since > they are designed as purely speech codecs, they are probably not of > much interest to you, though I heard that someone did write a MATLAB > implementation of one of those at some point. I may be wrong, and I > heard about that after I left UdeS anyways... > > Cheers, > Joachim > > On 9 April 2014 11:57, JesterN Alberto Novello <jestern77@xxxxxxxx> wrote: > > Dear List, > > I'm reviewing the state of the art of Perceptual Audio Codecs. For this > > reason I tried collecting some available MATLAB codecs for testing > quality > > (in perceptual experiments), compression ratio and speed. I realised > there > > is not so much code available out there and mostly quite old (probably > for > > commercial copyright reasons). So I thought of asking here if any of you > has > > some links to suggest about some available code (C, C++ also possible) > > possibly less than a decade old. > > Thanks a lot > > Alberto > > > > || | | ||| | || || | ||||| || | || | ||| | ||||| | | ||| | |||| | || > |||| > > > > ALBERTO NOVELLO / JesterN > > site: jestern.com > > shop: jestern.bandcamp.com > > audio: soundcloud.com/jestern > > video: vimeo.com/jestern > > > > || | | ||| | || || | ||||| || | || | ||| | ||||| | | ||| | |||| | || > |||| > > > > If for any reason you wish not to receive any more messages from this > email, > > please send an email with REMOVE as subject. I'm sorry for the > > inconvenience. > > Se per qualsiasi ragione non desideri ricevere piu' messaggi da questo > > indirizzo, mandami un messaggio con REMOVE nel soggetto. Mi scuso per il > > disturbo. > > > > -- > Joachim Thiemann :: http://jthiem.bitbucket.org :: > http://signalsprocessed.blogspot.com > -- James D. (jj) Johnston Independent Audio and Electroacoustics Consultant --047d7b342d30db878204f6da0e9a Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div>I have to ask: Is this OFFICIAL source code the best = known encoder?</div><div><br></div><div>You can also get reference models f= or later MPEG systems, but the question remains there, as well.</div></div> <div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">On Sat, Apr 1= 2, 2014 at 12:09 AM, Joachim Thiemann <span dir=3D"ltr">&lt;<a href=3D"mail= to:joachim.thiemann@xxxxxxxx" target=3D"_blank">joachim.thiemann@xxxxxxxx= </a>&gt;</span> wrote:<br> <blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p= x #ccc solid;padding-left:1ex">Hello again Alberto,<br> <br> I just want to point out that you can get _official_ source code for<br> two low-bitrate audio codecs: AMR-WB+ and EnAAC+, from the 3GPP<br> standards body. =A0They are very descriptively titled TS26.304 and<br> TS26.410 (for AMR-WB+ and Enhanced aacPlus respectively), and can be<br> downloaded from <a href=3D"http://www.3gpp.org/DynaReport/26-series.htm" ta= rget=3D"_blank">http://www.3gpp.org/DynaReport/26-series.htm</a>. =A0There<= br> are fixed-point versions as well, but the float versions are far more<br> understandable.<br> <br> Enhanced aacPlus - if my memory still somewhat right from 10 years ago<br> - is basically AAC tuned for low bitrate, with bandwidth extension and<br> parametric stereo.<br> <br> AMR-WB+ is a dual-mode LP-based codec, switching between CELP and a<br> transform to code the residual, also with bandwidth extension and<br> parametric stereo.<br> <br> If you look around on the 3GPP website you can also find the source<br> for the ancestors of AMR-WB+ (named, well, AMR and AMR-WB). =A0Since<br> they are designed as purely speech codecs, they are probably not of<br> much interest to you, though I heard that someone did write a MATLAB<br> implementation of one of those at some point. =A0I may be wrong, and I<br> heard about that after I left UdeS anyways...<br> <br> Cheers,<br> Joachim<br> <div><br> On 9 April 2014 11:57, JesterN Alberto Novello &lt;<a href=3D"mailto:jester= n77@xxxxxxxx">jestern77@xxxxxxxx</a>&gt; wrote:<br> &gt; Dear List,<br> &gt; I&#39;m reviewing the state of the art of Perceptual Audio Codecs. For= this<br> &gt; reason I tried collecting some available MATLAB codecs for testing qua= lity<br> &gt; (in perceptual experiments), compression ratio and speed. I realised t= here<br> &gt; is not so much code available out there and mostly quite old (probably= for<br> &gt; commercial copyright reasons). So I thought of asking here if any of y= ou has<br> &gt; some links to suggest about some available code (C, C++ also possible)= <br> &gt; possibly less than a decade old.<br> &gt; Thanks a lot<br> &gt; Alberto<br> &gt;<br> &gt; || | | ||| | =A0|| =A0|| | ||||| || | || | ||| | ||||| | | ||| | |||| = | =A0|| ||||<br> &gt;<br> &gt; ALBERTO NOVELLO / JesterN<br> &gt; site: <a href=3D"http://jestern.com" target=3D"_blank">jestern.com</a>= <br> &gt; shop: <a href=3D"http://jestern.bandcamp.com" target=3D"_blank">jester= n.bandcamp.com</a><br> &gt; audio: <a href=3D"http://soundcloud.com/jestern" target=3D"_blank">sou= ndcloud.com/jestern</a><br> &gt; video: <a href=3D"http://vimeo.com/jestern" target=3D"_blank">vimeo.co= m/jestern</a><br> &gt;<br> &gt; || | | ||| | =A0|| =A0|| | ||||| || | || | ||| | ||||| | | ||| | |||| = | =A0|| ||||<br> &gt;<br> &gt; If for any reason you wish not to receive any more messages from this = email,<br> &gt; please send an email with REMOVE as subject. I&#39;m sorry for the<br> &gt; inconvenience.<br> &gt; Se per qualsiasi ragione non desideri ricevere piu&#39; messaggi da qu= esto<br> &gt; indirizzo, mandami un messaggio con REMOVE nel soggetto. Mi scuso per = il<br> &gt; disturbo.<br> <br> <br> <br> --<br> </div>Joachim Thiemann :: <a href=3D"http://jthiem.bitbucket.org" target=3D= "_blank">http://jthiem.bitbucket.org</a> ::<br> <a href=3D"http://signalsprocessed.blogspot.com" target=3D"_blank">http://s= ignalsprocessed.blogspot.com</a><br> </blockquote></div><br><br clear=3D"all"><br>-- <br><div>James D. (jj) John= ston</div><div>Independent Audio and Electroacoustics Consultant</div> </div> --047d7b342d30db878204f6da0e9a--


This message came from the mail archive
/var/www/postings/2014/
maintained by:
DAn Ellis <dpwe@ee.columbia.edu>
Electrical Engineering Dept., Columbia University