How to playback ilbc files?

hallo,
i use asterisk 11.5.1 on my raspberry pi for an outdoor project, cpu power is an issue. i record phone calls (with ilbc codec) with “MixMonitor” in files with the extention xxx.ilbc

this files, i want to play back with “ControlPlayback” but it wont work with ilbc codec, with gsm its working.

does anybody know an application that could handle ilbc files for playback?
best,
hubert