[Asterisk-Users] music on hold without mpg123

[Matt Roth]

Lenz wrote:

> Hello list,
> after the last time that mpg123 wen ballistic on our production 
> system, we  decided to skip mp3 playback altogether and to go for raw 
> files. After  half an hour playing with mpg123 and sox parameters in 
> order to translate  a mp3 file to a wav file that can be streamed back 
> through * with no need  for an mp3 decoder, I thought I'd post the 
> result to the list to avoid  wasting time in the future:
>
> The correct paramater set seems to be:
>
> mpg123 -s --rate 44100 --mono /src/mp3/fpm-sunshine.mp3 > 
> fpm-sunshine.raw
> sox -r 44100 -w -s -c 1 fpm-sunshine.raw -r 8000 -c 1 fpm-sunshine.wav
>
> I have also prepared a small tutorial explaining how to setup the 
> whole  thing (you can find it at 
> http://www.oinko.net/astrecipes/index.php?n=152  - feel free to add or 
> modify it if you think it's necessary).
>
> Thanks
> l.

Lenz,

This method is referred to as file-based or native MOH, and I have some 
additional information regarding it.  First, a short post on why we 
moved from the rawplayer method to native MOH on our production box, 
with a quote from Kevin Fleming regarding the impact the change would 
have on scalability.

 - 
http://lists.digium.com/pipermail/asterisk-users/2006-February/141180.html

Second, I *believe* (please correct me if I'm wrong) that in order to 
get the full benefits of native MOH, the music files should be converted 
to the codec that the calls will be in.  This allows Asterisk to play 
MOH without performing any transcoding, which lowers the resource 
utilization on the box.  Here is a guide for converting WAV files to the 
desired codec, which addresses the four characteristics that describe 
audio data.

- http://lists.digium.com/pipermail/asterisk-users/2006-March/142108.html

Please feel free to add any of this information to your site and don't 
hesitate to contact me if you spot any mistakes.

Thank you,

Matthew Roth
InterMedia Marketing Solutions
Software Engineer and Systems Developer