Are you using the alsa output plugin with routing to pulseaudio? I remember this from Ubuntu systems. Running mpg123 -o pulse works, -o alsa plays static noise. Maybe some byte offset not aligned to the data type ... I suspect the link from alsa to pulse is faulty, as mpg123's alsa output module has been working fine for a long time now using proper alsa.
You also can verify that the decoding works by storing output to a file using -w output.wav. Alrigthy then, Thomas (mpg123 upstream) unterwegs ohne Signatur
