IRIX and Software

Mplayer OpenGL acceleration?

Does anyone know why Mplayer's OpenGL and SGI acceleration never seems to work with any of the MGRAS boards? Is it only intended for the Vpro stuff? The typical AVI's play fine without it but I'm sure there could be some benefit if it was possible to get those working.
:O2: O2 - (Mantadoc) - R5K - 200MHZ - 128MB RAM - 6.5.30
:Octane: Octane - (Montrealais) - R12K - 2*360MHZ - 1024MB RAM - EMXI. - 6.5.30
Alphaserver DS10 - (Vandoc) - EV6 - 466MHZ - 256MB RAM
Sun Ultra 5 - (Quedoc) - UltraSparc II - 400MHZ - 512MB RAM
ASUS K55VD - (Mapleglen)- I5 - Dual Core 2.5GHZ - 8 GB RAM
Dell L502X - (Algorail) - I7 - Quad Core 2GHZ - 6 GB RAM
Well seems using the format=RGB24 and GL options sometimes actually makes it work.
:O2: O2 - (Mantadoc) - R5K - 200MHZ - 128MB RAM - 6.5.30
:Octane: Octane - (Montrealais) - R12K - 2*360MHZ - 1024MB RAM - EMXI. - 6.5.30
Alphaserver DS10 - (Vandoc) - EV6 - 466MHZ - 256MB RAM
Sun Ultra 5 - (Quedoc) - UltraSparc II - 400MHZ - 512MB RAM
ASUS K55VD - (Mapleglen)- I5 - Dual Core 2.5GHZ - 8 GB RAM
Dell L502X - (Algorail) - I7 - Quad Core 2GHZ - 6 GB RAM