First post, by Standard Def Steve
Just noticed this today as I was playing a 34 Mb/s 1080p MPEG-2 encoded MKV file ripped from a Blu-ray disc. MPC-HC indicated that DXVA was being used, and sure enough, CPU usage was at around 8%. I was using a dual core S939 Opteron overclocked to 3.0GHz. The video card tested was a 640MB 8800GTS running 341.44 on Win7 x64.
I always thought that the old G80 was incapable of full bitstream decoding even with MPEG-2, so this was kind of a pleasant surprise!
A 32 Mb/s h.264 stream ripped from a another BD was a different story. With this format, MPC-HC did not use DXVA and CPU usage was around 35-62%.
Interestingly, ATI cards of that era don't appear to support full bitstream decoding. Playing the same 34 Mb/s MPEG-2 stream with a Radeon X1950 XTX resulted in significantly higher CPU usage: around 15-30%. MPC-HC did not enable DXVA with the X1950 XTX.
I wonder if GeForce 7 can perform full MPEG-2 bitstream decoding as well? Apparently they use the same video engine as the G80-based cards. I'm gonna have to dig up my old 7950GT and find out!
94 MHz NEC VR4300 | SGI Reality CoPro | 8MB RDRAM | Each game gets its own SSD - nooice!