Hello,
when I make menuselect I see that the default formats selected for core sounds is gsm and for music on hold wav.
Why arn’t the same?
Thanks in advance
I m not a codec specialist but what i think is:
gsm is a better codec for voice (not too much bandwith and too much cpu needed) and the core sounds are mostly voice.
wav is a better codec for music (better quality but more bandwith). Playing music converted to gsm sounds not that great.
So, they set default the best codec for what it is needed?
GSM minimises disk space for voice. GSM is totally unsuitable for anything but voice, so a less aggressive codec has to be used for music.
Ideally, you should have the formats for all codecs that you actually use installed.
The purpose for downloading all those sound packs it to avoid doing unnecessary transcoding.
If you have a SIP/IAX client using GSM listening to voice prompt, the sounds from the GSM pack will be used, same thing for example for G729.
If for example you have G729 clients going through a G729 outbound trunk, they can make calls even if you don’t have the G729 codec installed, but if you want to use voice prompts for them and you don’t have the .G729 pack, they will not be able to hear anything (because asterisk will try to transcode .sln or .wav or whatever you have availble to G729 and will not be able to do it without a G729 codec).
Best advice, if you’re going to experience with a lot of codecs (and CPU intensive codecs like G729, iLBC, GSM) and planning on playing voice prompts (they are used for example in the Voicemail application), you should get at least those sound packs.
Hope this helps.