Since my constant companion, the video ipod, cannot play Speex format, I needed to convert a bunch of files .spx files to mp3 format.
This shell script should do the work for you (it will work for files with spaces in them)
sudo find ./ -name '*.spx' | while read FILE; do ogg123 -d wav -f - "$FILE" | lame - "$FILE.mp3" ; done
The -d wav -f - argument to ogg123 make it(ogg123) use the WAV driver
and output the result to the stdout (given by -f -). The stdout from
ogg123 is passed to lame, which converts the wav to mp3. Caveat: The
id3 info in the spx file is lost and you have to add that to the mp3
files manually.
One interesting thing I came to know in this was how to loop over
files with spaces in them. This is done by piping the result of find
to the while read part. More details of this is here