Video Enhancer Won't run CPU at 100%

[Manoman455]

I noticed after I upgraded my computer and reinstalled video enhancer that while running, my CPU utilization isn't 100%. It is only at ~25%. I was wondering what could be the problem since I know on my older build, video enhancer was very straining on the CPU and would shoot the utilization up to near 100%.
Here is some info.
Video Enhancer 1.9.6 - advanced mode.
Intel core i7-2600 @ 4.8 GHz
video was an AVS with input as a mkv with a mpeg2 video stream and an ac3 audio, filters were converttoyv12, uncomb, nnedi3_rpow2(rfactor=2), lanczos4resize(1280,720). there is also cropping but I doubt that is the problem.

I don't know if this is a problem or not but it just ticked me off a little, thinking that if it was at 100% utilization it would have processed my video faster, that instead of ~4 hours it could have been done in ~1 hour.

If this turns out to be not a problem but normal behavior then it would set me at ease a bit.

Thanks for listening.

[Dee Mon]

You've got 4 cores that can do 8 things at one time. To utilize 100% you need to have 8 parallel computations fully loading their CPU parts (units). However everything that happens inside AVS script is done sequentially, not parallel, it can only load 1/8 of your CPU. Each of the filters also works sequential and Video Enhancer tries to run each filter in its own thread, so they can work in parallel. However since they work in chain, one's input is another one's output, so the total speed is limited by the slowest link of the chain. It may be either AVS part with decoding or the nnedi3 part or writing to hard drive (especially with high bitrates or uncompressed video). This slowest part utilizes 100% of one of your 8 units, so it's 12.5%. Other parts (filters) can work faster but have to wait for the data from the slowest part, so they utilize less than 100% of their units. In this case together they load ~100% of another your CPU unit, so you have 2 fully loaded units and 6 unloaded, that's 25% of total CPU load.

To load multicore CPUs effectively we need parallel implementations of decoders, encoders and filters and also fast hard drives. SR in Video Enhancer is such a parallel filter, it scales to all available units and performs computations in parallel. But most VD filters are not parallelized, they can only load one of your 8 units.

[Manoman455]

Thanks for the info and quick reply. i didn't realize or even think about the filters, I was thinking it was AVISYNTH altogether was the problem.
well thanks again.

[CruNcher]

Avisynth has no Finalized Multithreading Framework though every Plugin can make use of it itself their are some solutions for overall multithreading but they are only experimental (Avisynth Mt and Threadrequest being the most used ones). The heaviest filter without doubt in your script here is nnedi3 though it's Multithreaded you should also check as Dimitry said your Decoder side it could be the bottleneck here. Mpeg-2 Multithreading based on Slices for example was just added to FFMPEG same for H.264 and others (they are still being optimized though).
Btw Dimitry what do you think of Fatall et all and Shane at all approaches though they are not Motion based but the results doesn't look bad for Single Frame based super resolution approaches same as needi, are they worth to compare vs Video Enhancer ?
Though looking @ fatalls demo it doesn't look that impressive http://ftp://ftp.cs.huji.ac.il/users/raananf/demo.mpg

[Manoman455]

hmm thanks for the info, never really looked at all that for avisynth since i just download the plugin and use them.

[SeeingMole]

There is a multithreaded version of Avisynth.

http://forum.doom9.org/showthread.php?t=148117

To install it, simply extract avisynth.dll from the archive, then copy to your "Windows\System32" (on 64bit systems, use "Windows\SysWOW64")

Files in the plugins folder goes to "Program Files (x86)\Avisynth" folder.

Please give some feedback if it works better or not.

[Manoman455]

sorry have already been using that for a while now after my last post, not using it anymore as a lot of the filters didn't seem to work correctly, but for ones that was provided (not that many) they worked well.