Scaling HD for mobile or lower res

[Lele-brz]

Hi,
I noticed that when scaling from HD using BicubicResize, the usage of x264 in not 100% of CPU.
Just removing the resize x264 can take advantage of all CPU power.
Is there some other scaling to use, from 1280x720 to 256x144?
Just to have maybe a sharper image and not be a bottleneck for ecoding.

Thanks in advance

[thetoof]

Dunno if that's really faster (can't test atm), but you can call reduceby2() a few times before the final resize. Or do a lossless rendering pass.... but it's not really worth it if you're only resizing.

[mikeytown2]

u can try SimpleResize() (http://www6.impacthosting.com/trbarry/downloads.htm) or BilinearResize() for more speed.

Also not sure but this might be faster then ReduceBy2()

AssumeFrameBased().SeparateFields().SelectEven().TurnLeft().AssumeFrameBased().SeparateFields().SelectEven().TurnRight()

Here's the equivalent to ReduceBy4()

AssumeFrameBased().SeparateFields().SelectEven().AssumeFrameBased().SeparateFields().SelectEven().TurnLeft().AssumeFrameBased().SeparateFields().SelectEven().AssumeFrameBased().SeparateFields().SelectEven().TurnRight()

[Alex_ander]

@ mikeytown2
I'm a bit skeptical about simply dropping lines and columns (especially doing it twice): this means you are sampling a function without previously limiting its bandwidth to the half sample frequency value. ReduceBy2() is not the same (it uses all pixels) and therefore is more safe. However I'd (only once) drop even or odd lines to remove interlacing (if any), then resize.

[Lele-brz]

Thanks for replying,
I guess there's no multi-threaded scaling in Avisynth?

[kemuri-_9]

afaik, nothing internal to avisynth supports multiple threads,
there have been some filters developed to be multithreaded
but natively it's single threaded within a single instance...
it's 'multithreaded' in the fact that you can have several instances of avs going at one time

[Blue_MiSfit]

SetMTMode in the multithreaded Avisynth build should improve things a bit.

~MiSfit