Triangles are usually not enough, you want textures too. If you're playing video you are faced with some though choices:
- stream the compressed video (the display has to be able to decode the format).
- transcode the video to a format supported by the display (expensive without dedicated hardware).
- stream uncompressed video (back to 60 frames of HD).
Clearly, the best option is hardware assisted transcoding. But then, why not use that hardware to compress on the fly the HD video, and keep the whole architecture a lot more simple in the first place? Food for thought.