+ * first version by Francois Revol (revol@free.fr)
+ * fringe ADPCM codecs (e.g., DK3, DK4, Westwood)
+ * by Mike Melanson (melanson@pcisys.net)
+ * CD-ROM XA ADPCM codec by BERO
+ * EA ADPCM decoder by Robin Kay (komadori@myrealbox.com)
+ * EA ADPCM R1/R2/R3 decoder by Peter Ross (pross@xvid.org)
+ * EA IMA EACS decoder by Peter Ross (pross@xvid.org)
+ * EA IMA SEAD decoder by Peter Ross (pross@xvid.org)
+ * EA ADPCM XAS decoder by Peter Ross (pross@xvid.org)
+ * MAXIS EA ADPCM decoder by Robert Marston (rmarston@gmail.com)
+ * THP ADPCM decoder by Marco Gerards (mgerards@xs4all.nl)
+ *