I’m trying to convert some MP3s to something that my 1.4 Asterisk can play.
I’ve started by converting the MP3s to wav and normalising using MediaMonkey.
Then using SOX, I can create the basic 8khz, mono .sln/.gsm files, but, most of my internal devices are HD audio capable (eg Yealink T22). So I’d prefer to create formats/qualities appropriate to them as well. I’ve tried using sox for creating-t ul and -t al (ulaw/alaw) formats, but I think its the bitrate I’m messing up.
If I do a show channel command on a call, it tells me that the MBR for most of my calls is 384kbps.
If I try using something like -r 64k instead of -r 8k it just gets put to 50% speed.
So I’m scratching my head on how to create files that internally would sound quite good, but externally would be 8khz.
Any ideas ?