Just us it like this:
mpg123 -s something.mpg >something.cdr
The file format is not .wav, but in the format that may be burned
directly by cdrecord if you do this:
cdrecord -v speed=S dev=X,Y,Z -swab -pad -audio *.cdr
assumes X86 architecture. Don't use -swab on SPARC
Substitute the speed for your burner/cdrs and your own X,Y,Z config
obtained by runnign cdrecord -scanbus. This will burn all the .cdr files
in the directory that you're sitting in.
This is the script I use, just put the mp3 files in the ~/burn/data
# This is a CD-R script for burning mp3 files directly to CD.
# The mpg123 program converts mp3s to cdr format, and cdrecord burns
# the tracks on the CD.
for I in /home/foo/burn/data/*.mp3
mpg123 --cdr - "$I" | cdrecord dev=0,0,0 -audio -pad -v -speed=2
cdrecord dev=0,0,0 -fix