When it comes to outputting HD content from a PC to an HDTV, it can actually take a surprising amount of horsepower to decode and display such a large amount of data (1080p amounts to 124.416 megapixels per second of raw data). This can bring an aging media center to its knees rather quickly.
ATI and nVidia have both developed technologies (Avivo and PureVideo, respectively) that seek to offload this processing to the video card, which is a more logical place for it to occur for a couple reasons. First, today’s powerful video cards are completely underutilized most of the time. Second, these programmable GPUs are capable of taking some specific tasks and performing them at rates that would make your CPU whimper softly in the corner.
So that’s the good news. The bad news is that these technologies are completely unintuitive to make work, although progress is being made. You can’t just install the video driver (which includes the Avivo/PureVideo technology) and automatically have accelerated video, although that’s exactly how it SHOULD work. What they don’t tell you is that you also have to have a properly accelerated DirectShow codec, supporting application, and some magical settings in place for it to finally feel like offloading the processing to the right place.
PowerDVD 8 is a popular choice (I think it was the only choice for a long time), but it doesn’t support MKV files, which was something I required. Renaming them to MP4 seemed to sidestep that limitation, and PowerDVD would play them with a marked improvement in performance. However, I don’t like PowerDVD, nor do I have any desire to shell out the $80 to make this all work.
However I stumbled upon a better choice. I’ve used Media Player Classic and the K-Lite Codec Pack for a long time now, but hadn’t seen the latest version. I noticed that K-Lite now included a forked version of MPC called Media Player Classic – Home Cinema, modified to accelerate video just as I’m looking to. I used K-Lite 4.4.5.
In the components section, I used a default install. However, you need to enable a few extra things in the Additional Tasks area:
- Video Renderer set to EVR Custom Presenter
- Use Internal subtitle renderer (instead of DirectVobSub)
- Enable internal H.264/VC-1 DXVA decoders
The installer takes care of the rest, and I definitely want to thank the K-Lite guys for putting that together. They’ve done a good job at making this process actually possible to do for the average person, instead of the impossible situation I was running into before.
On my quad-core/GeForce 8800GT, this dropped CPU usage from 13-20% to a mere 0-1%. For my Opteron 2.2GHz/GeForce 7900GS Media Center, 1080p video that wasn’t playable before would now play correctly using about 85-90% CPU.
I hope this information helps someone. I wanted to write it out because it took many hours of researching, testing, and playing with settings in Media Player Classic to actually get this working situation. I’m glad it does now, but I wish the companies involved had made things easier on the consumers. Most people will never know the capabilities that their computer may have and it’s a shame to have a useful technology like this go to waste.
