I digged a little further and found for example that while the iphone 3GS/4 has almost the same GPU as the N9, it has a VXD core that takes all the video decoding (all profiles) (ie GPU + media core). Quite hard to find very precise specs for the N9 or for TI to know what the N9 hardware is capable of. Maybe someone else could tell.

Edit:
@cloud596: thanks for the precisions.