Hi10P 1080p video... i can play it smoothly if i set mpc-hc affinity to 2 cpu, 3.7GHz, absolutely smooth,
or set to 3 cpu with only 1GHz, also smooth but cpu usage is 100% for all cores.
Decoder is Divx7 h264 < fastest free software h264 decoder imho.
Disabling Aero/desktop composition will improve performance, may be.

h264 software-based decoder is pretty fast nowadays, my thuban 3.7GHz can play 4 bluray videos simultaneously, original uncompressed 35Mbps without lag, or playback 7 instance of 1080p compressed(~2mbps) fansub, simultaneously.
decoder is ffdshow, Divx7 sure can do alot better.
While Dxva decoder cant do that, the gpu driver will crash lol.

tri-core or quad core's cpu user shouldn't worry about playing 1080p, it will smooth unless the decoder has prob, or mis-configured player.
As for Dxva with Hi10p support, it prolly just matter of time, at first, Nvidia was the only GPU that can decode the 1080p with More than 4 reference frame, while Ati/amd couldn't, but later max 4 reference frame restriction was "unlocked" on newer Catalyst.

Ati drive quite buggy, every new catalyst come out sure got something broke lol, even it's WHQL'ed, if aint broken, dont update gpu driver
For flawless Dxva playback you should read the first page, or here : http://imouto.my/watching-h264-videos-using-dxva/
If someone installed too many codecs, they will override the default h264 decoder, or user does not know how to configure.

Always try to play your h264 video with wmp12 first , cause it support Dxva by default, 'cept hi10p, and check for cpu usage, if its high prolly means dxva does not work.
Or try dxva checker: http://bluesky23.yu-nagi.com/en/#DXVAChecker

Btw who are they?

All use Lanczos processing, 4 taps, probably sharpest (was using the same setting on ffdshow).
But i think the scaling will not be used if your video dimension is same as your monitor dimension, eg 1080p, so it's prolly useful if watching 480p or 720p videos.

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Added on March 2, 2012, 1:01 amnvidia 3d stereoscopic?
never tried it before cause im using normal lcd

if its really so easily convert the normal video to 3d video,
some one would have added a video filter that can do that in realtime to ffmpeg or ffmpeg based video codec/filters,
or pixel shader codes added to mpc-hc


This post has been edited by 1024kbps: Mar 2 2012, 01:01 AM

well its the sharpest seting on ffdshow, i upscale any video to 1080p(except some super low res) to make the subtitle does not look like crap
i know madvr have more better scaler, but i only use madvr cause its faster than evr-cp.

Isnt that most of the Dxva decoder are the same? except Lavfilters
Do you mean madvr cant render video smoothly? whats your gpu?

Whats the difference? need proof
Madvr currently does not support Dxva, as the current Dxva need compatible video renderer to working correctly, eg EVR/CP, on Vista/7.
Currently only CUDA decoder can work independently (Lavfilter and CoreAVC).
I remember the mpc-hc dev said he want to make one MFT based decoder(does not rely on video renderer too.), but its long time ago already, not sure when he will finish it

MadVR need main stream GPU iirc, i dont own a mid end GPU so i cant test it for you.
Exclusive fullscreen/disable Aero, may solve your problem but its buggy on my side, you could try it though, if not just use normal video renderer is enough, and use it with ffdshow scaler if you have fast quadcore CPU.
since most of the time you cant notice the different between two renderer