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vocoder transcoding question

Started by radiohead September 24, 2003
hello, 
i am endeavoring to transcode G.729 r8 to G.711 as my first serious
DSP project for a production environment.
I am seeking any relevant resources including how-tos, reference docs,
tutorials, working code, ..annnything

I am fairly new to DSP and don't really have much of an idea of how to
get started.
Any advice is GREATLY appreciated
regards
chris
In article b9fce656.0309241506.442f853c@posting.google.com, radiohead at
lappin_h@yahoo.com wrote on 09/24/2003 19:06:

> hello, > i am endeavoring to transcode G.729 r8 to G.711 as my first serious > DSP project for a production environment. > I am seeking any relevant resources including how-tos, reference docs, > tutorials, working code, ..annnything > > I am fairly new to DSP and don't really have much of an idea of how to > get started.
maybe by telling us whatever the hell G.729 r8 and G.711 are. are they some kinda spec or standard? i have some experience with vocoder but not with G.729 r8 or G.711. r b-j
I can't really see why you chose G.729 and G.711. G729 is a CELP codec
and G.711 is just companded PCM. So effectively your only job would to
decode G.729 (which is quite some work if you write the decoder) and
encode it again to G.711 (which is trivial).

To me transcoding makes real sense only where the two set of codecs
are alike in many respects and you can convert one format to another
without having to go through entire decoding-encoding cycle and
thereby save processing. It it also here that your ideas and
originality come into picture.

Regards
Piyush


lappin_h@yahoo.com (radiohead) wrote in message news:<b9fce656.0309241506.442f853c@posting.google.com>...
> hello, > i am endeavoring to transcode G.729 r8 to G.711 as my first serious > DSP project for a production environment. > I am seeking any relevant resources including how-tos, reference docs, > tutorials, working code, ..annnything > > I am fairly new to DSP and don't really have much of an idea of how to > get started. > Any advice is GREATLY appreciated > regards > chris
robert bristow-johnson <rbj@surfglobal.net> wrote in message news:<BB97F46B.3D50%rbj@surfglobal.net>...
> In article b9fce656.0309241506.442f853c@posting.google.com, radiohead at > lappin_h@yahoo.com wrote on 09/24/2003 19:06: > > > hello, > > i am endeavoring to transcode G.729 r8 to G.711 as my first serious > > DSP project for a production environment. > > I am seeking any relevant resources including how-tos, reference docs, > > tutorials, working code, ..annnything > > > > I am fairly new to DSP and don't really have much of an idea of how to > > get started. >
in general,you should get the spec,test vector,and something you can get. then trancode the source code to you favarate language(here in general is c and assembly),pass the test vector,and if necessary,optimize your code,but if you arrive the performance,congraduation! you have finished your task.
robert bristow-johnson <rbj@surfglobal.net> wrote in message news:<BB97F46B.3D50%rbj@surfglobal.net>...
> In article b9fce656.0309241506.442f853c@posting.google.com, radiohead at > lappin_h@yahoo.com wrote on 09/24/2003 19:06: > > > hello, > > i am endeavoring to transcode G.729 r8 to G.711 as my first serious > > DSP project for a production environment. > > I am seeking any relevant resources including how-tos, reference docs, > > tutorials, working code, ..annnything > > > > I am fairly new to DSP and don't really have much of an idea of how to > > get started. > > maybe by telling us whatever the hell G.729 r8 and G.711 are. are they some > kinda spec or standard? > > i have some experience with vocoder but not with G.729 r8 or G.711. > > r b-j
--hi, they are vocoders used in telecom
piyushkaul@yahoo.com (Piyush Kaul) wrote in message news:<2e20232a.0309250259.463fed34@posting.google.com>...
> I can't really see why you chose G.729 and G.711. G729 is a CELP codec > and G.711 is just companded PCM. So effectively your only job would to > decode G.729 (which is quite some work if you write the decoder) and > encode it again to G.711 (which is trivial). > > To me transcoding makes real sense only where the two set of codecs > are alike in many respects and you can convert one format to another > without having to go through entire decoding-encoding cycle and > thereby save processing. It it also here that your ideas and > originality come into picture. > > Regards > Piyush > > > lappin_h@yahoo.com (radiohead) wrote in message news:<b9fce656.0309241506.442f853c@posting.google.com>... > > hello, > > i am endeavoring to transcode G.729 r8 to G.711 as my first serious > > DSP project for a production environment. > > I am seeking any relevant resources including how-tos, reference docs, > > tutorials, working code, ..annnything > > > > I am fairly new to DSP and don't really have much of an idea of how to > > get started. > > Any advice is GREATLY appreciated > > regards > > chris
hi-- i didn't choose them, they are what i have to work with. G.729 is de facto voip codec and i've got calls coming into my soft switch that have to be transcoded for use on the pstn...therefore, G.711 chris