[M4IF Technotes] What does AMR stand for? / Where's CELP

[Alain Tritschler]

Don't think it's in GSM.
I still think it's useful even for voice application as soon as it enables
to optimize the bandwidth and reduce the call rejection rates by reducing
the bandwidth/bitrate per user when there are peaks. You'd have a low
bandwidth and reduced voice quality instead of nothing.
Alain
> -----Message d'origine-----
> De : Bruce Schulman [mailto:bruce   vici.us]
> Envoyé : vendredi 14 mars 2003 15:52
> À : 'Alain Tritschler'; 'Ralph Neff'; Technotes   lists.m4if.org
> Cc : 'Ben Waggoner'
> Objet : RE: [M4IF Technotes] What does AMR stand for? / Where's CELP
>
>
> Alain,
> Is AMR used in GSM?  I don't think it was useful until 2.5G or 3G.  So,
> would it be the case that "adaptive" bit rate is only useful in certain
> types of mobile communications - like packet based networks or
> CDMA and not
> TDMA networks.
>
> Bruce Schulman
> ============
> VICI
> "VIrtual Components: Silicon IP Licensing, Development, Optimization"
> web    www.vici.us
> tel/fax  408-404-7120
> e-mail  bruce   vici.us
>
> -----Original Message-----
> From: technotes-admin   lists.m4if.org
> [mailto:technotes-admin   lists.m4if.org]On Behalf Of Alain Tritschler
> Sent: Friday, March 14, 2024 3:19 AM
> To: Ralph Neff; Technotes   lists.m4if.org
> Cc: 'Ben Waggoner'
> Subject: RE: [M4IF Technotes] What does AMR stand for? / Where's CELP
>
>
> > Regarding CELP, my interpretation is that low
> > bitrate speech codecs are most useful in the mobile
> > space, due to the low bandwidth and the fact that
> > 2-way speech communication is a core application.
> > But MPEG-4 CELP isn't specified by any of the mobile
> > standards (e.g. 3GPP, 3GPP2).
>
> My understanding is that AMR has a great advantage over CELP for mobile
> communications, which is that it is _adaptive_ : CELP allows a constant
> bitrate while it is possible to adapt the audio bitrate of AMR to network
> conditions.
> Also, the AMR codec implementation (normalized in both the encoder and
> decoder) is very efficient, while CELP (in the VM) is
> significantly slower.
>
> > Sure it's in ISMA, but the target application for
> > ISMA (one-way multimedia delivery, wide range of content,
> > transport via internet) makes generic audio coding
> > (AAC) much more interesting/useful than speech coding.
> >
> > -Ralph
> >
> >
> > -----Original Message-----
> > From: Ben Waggoner [mailto:ben   interframemedia.com]
> > Sent: Thursday, March 13, 2024 2:36 PM
> > To: Technotes   lists.m4if.org
> > Subject: [M4IF Technotes] What does AMR stand for? / Where's CELP
> >
> >
> > Folks,
> >
> >     I know I should know this, but don't seem to.  What does the
> > AMR acronym
> > actually stand for?
> >
> >     Also, anyone have a good story for why CELP audio
> > implementations are so
> > rare, even though the codec is part of ISMA?
> >
> >
> > Ben Waggoner <http://www.benwaggoner.com>
> > Compressed Video Consulting, Training, and Encoding
> >
> > My Book:            <http://www.benwaggoner.com/books.htm>
> > Cleaner e-book:     <http://www.cmpbooks.com/cleaner>
> >
> > Compression Classes at Stanford  June 30-July 4 and Aug 11-15
> > <http://www.digitalmediaacademy.org/compression.html>
> >
> >
> >
> > _______________________________________________
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>
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