# apt install lame # wget http://val.bmstu.ru/unix/Media/Knockin_on_Heavens_Door.mp3 # lame --decode Knockin_on_Heavens_Door.mp3 # sox -V Knockin_on_Heavens_Door.wav -r 8000 -c 1 Knockin_on_Heavens_Door.raw
# apt install ffmpeg $ cd /usr/share/asterisk/sounds/recordings/ $ sox -t al -r 8000 -c 1 speech.alaw speech.wav $ ffmpeg -nostats -loglevel 0 -i speech.wav -acodec libvorbis speech.ogg
# lame --preset voice -v -B 64 -a XYZ.wav XYZ.mp3