Can someone tell if is posible to play mp3 files with the Background() or Playback() applications, the goal is use an mp3 file as an IVR announcement, as i have done in elastix.
The easiest and most efficient way is to pre-convert them to signed linear or the target codec. You will not lose any quality by doing this as the codec used to the phone is what limits the quality.
Note that complex sounds with Background risk jamming the incoming DTMF.
Thanks David55, can u suggest me any software for do this?
file conversion was the most reliable resolution for this (SOX, Audacity)