After merging this change, there is support for the AMR codec (by means
of libopencore-amr, which is already used for EFR).
In terms of gapk formats, we introdude
* the "amr-opencore" format, which serves both as the canonical format,
and as the input format to opencore-amrnb itself.
* the "rtp-amr" format, which is the payload of RFC4867 octet-aligned mode
You can use the following command for a real-time RTP playback for AMR
frames:
./gapk -I 0.0.0.0/30000 -f rtp-amr -A default -g rawpcm-s16le