a separate array.
For the OGG version at http://www.bigbuckbunny.org/index.php/download/
this results in about 50% speedup of unpack_vlcs, resulting in ca. 20% faster
overall speed.


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@13729 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b