CPU clock (power plan) limitation not followed when DXVAcb is active

Describe the issue you're having:
Setting through a power plan (power configuration) to run the CPU at a 
percentage of the default speed, e.g. 2.9GHz default speed @ 75% = 2.2GHz, 
forces the CPU to run at full speed.

How can the issue be reproduced? Sample File?
Set in a power plan (advance power settings) > processor power management > 
maximum power state : 75%
Set LAV Video Decoder > Hardware Acceleration > DXVA2 (copy-back)
Use a CPU clock measurement tool, e.g. AIDA64, or recheck the setting above to 
notice full cock speed or 100% value even if the setting was previously 
altered. Will revert to 75% once the player is closed.

What version of the product are you using? In which Player?
0.55.3, MPCHC 1.6.6.6957, Win 7 32bit.

Please provide any additional information below.

Without a hardware decoder, the speed is not altered, each power profile I've 
set keeps its processor limitation and forces the clock to remain low, thus 
temperature and noise generated by the cooling fan is kept to a minimum. I use 
these power profiles to get the best comfort out of a hot CPU while watching 
movies by limiting the CPU speed.

It might not be directly related to LAV, as I've just tested CoreAVC with DXVA 
and it behaves the same, but it also might be possible to implement/fix this 
issue since LAV is all about media and it would be useful in an HTPC 
environment.

The really strange part is that DXVA should be lowering the CPU usage and 
increase the GPU usage. As my GPU is on the mainboard, the CPU still gets hot 
(SpeedFan) even when the usage graph (Sysinternals Process Explorer) shows a 
dim line and no real fluctuations while playing.

Original issue reported on code.google.com by ema....@gmail.com on 30 Mar 2013 at 3:18

MikaTake / lavfilters

CPU clock (power plan) limitation not followed when DXVAcb is active #339