Learned about dir2ogg over here and am using it to convert MP3 to OGG.
So… I installed dir2ogg:
# apt-get install dir2ogg
And then I ran it on some MP3s, and the generated OGG files sounded like chipmunks. I read the man page for dir2ogg and saw that it had an option for mp3-decoder. I tried specifying the lame decoder but it complained that it couldn’t find it, so:
# apt-get install lame
Then I ran dir2ogg with the following command and the ouput OGG files sounded proper!
$ dir2ogg --mp3-decoder=lame --quality=10 .