encoding with x264 and h264 codec only use 30-50% cpu

[Slind]

Hey,

do you have any idea what could slow down the encoding with x264 and h264 that it only uses 30-50% of the cpu power ?
It is the same on a hdd and 500mbit/s ssd, so it can´t be the drive which is slowing it down. I also made sure that it uses 12 threas on my 8 thread cpu. Is there anything else which I could try to improve it ?
I encode with the Adobe Media Encoder.

[Krispy Kritter]

I've seen similar results using VidCoder.

And reading is only half the process. The file gets encoded and then written to disk as well.

[Slind]

500mbit/s should still be more than enough. and it is the same cpu usage for the slow hdd and the fast ssd

[jagabo]

Obviously, disk I/O isn't the problem. With 12 threads on an 8 core CPU x264 will use nearly 100 percent of CPU time. So the problem must be in AME. It's not feeding frames to x264 fast enough.

[deadrats]

a lot depends on the settings you use, for instance if you set x264 to use full pel (i.e. no sub me refinement at all) then it's impossible to load a HT enabled quad core to 100%. the more aggressive settings you use the more calculations have to be performed and the more you will load up all the cores.

as a side note one has to ask themselves why one would use an $800 encoding software and then output using a free library that can be used from within other legally free encoding front ends.

even assuming that AME is a pirated copy (personally i don't care if it is or not) i still don't get why you would want to encode using x264 from within AME instead from within something like handjobbrake or similar open source crotch alternative.

people generally use AME for it's gpu accelerated encoding not for its x264 encoding, in all honesty i didn't even know you could output to x264 from within AME.

[Slind]

a lot depends on the settings you use, for instance if you set x264 to use full pel (i.e. no sub me refinement at all) then it's impossible to load a HT enabled quad core to 100%. the more aggressive settings you use the more calculations have to be performed and the more you will load up all the cores.

as a side note one has to ask themselves why one would use an $800 encoding software and then output using a free library that can be used from within other legally free encoding front ends.

even assuming that AME is a pirated copy (personally i don't care if it is or not) i still don't get why you would want to encode using x264 from within AME instead from within something like handjobbrake or similar open source crotch alternative.

people generally use AME for it's gpu accelerated encoding not for its x264 encoding, in all honesty i didn't even know you could output to x264 from within AME.

I use Premiere Pro for small cutting and adding an intro and outro and adobe audition for processing the audio and I use Adobe for work, too. So why should I use any other Software ? I tried MeGUI with the x264 codec, too. It is the same 30-50% cpu usage.
You are talking about why I use a free codec the x264, well do you know any better codec for a small filesize and best quality, h264 can´t keep up. (for online streaming)

[poisondeathray]

If it's 30-50% CPU usage from using x264 CLI , then it's likely the settings used . Some settings are poorly multithreaded (eg. --b-adapt 2) , other settings are just incredibly slow, causing a bottleneck for other things in the pipeline

[Slind]

The settings I use, do you see anything which could be improved ?

[poisondeathray]

There must be another problem. Are you sure you only get <50% in megui with equivalent settings? What are you feeding megui as input ? Maybe some other filters are bottleneck ?

Those look almost like the equivalent to default "medium" settings in your screenshot .

It will be slightly slower with x264vfw (it just is slightly slower, don't ask me why, maybe because of VFW, maybe some overhead)

Are you sure you want to change them ? faster settings implies larger filesizes at the same "quality" level , or worse quality at similar filesizes . ie. "faster " settings are less compressed

[Slind]

Hey,

quality is more important than speed for me, I´m not google chrome


I tried two things with megui, one via frameserver and one without it (directly from the source without any cutting and audio changes).

[poisondeathray]

Frameserver should be slower, but what format was the source when you used that directly ?

[Slind]

the sourcefile is YV12 within a .avi

[poisondeathray]

I don't know why . You should be seeing >90% avg. usage if it's just HD footage

Weren't these screencaps ? For some tutorial series ? If quality and low filesize were important, then you could optimize them by using more suitable but slower settings - usually more b-frames (often there gaps where there is no screen activity) , b-adapt 2 , longer keyframe intervals (if quick seekability / navigation is not a concern). Or even do VFR encodes (duplicates aren't even coded, cost less than b-frames) . But if it was for hosting on some re-encoding site like youtube, then it's not worth using VFR

[Slind]

yeah, some of them are on vimeo..

mhh, atm I let the encoding run during doing something other, because the pc isn´t slowed down for office use. but I would love to speed it up that I can encode 10-20 hours over night.

[_Al_]

put your avi and BATCH file into Megui's folder where x264.exe is and try to run that test.BAT, check CPU

create in notepat and name it test.BAT:
@echo off
@x264 --crf=18 --output.mp4 input.avi
@echo+
pause

[Slind]

what do you mean where the x264.exe is.

Should I put into MeGUI/tools/x264 or MeGUI/ ?

[Slind]

within the x264 folder I get

x264: unkown option -- output.mp4

[_Al_]

sorry for a typo:
--output out.mp4

[Slind]

x264 [error]: not compiled with MP4 output support

with out.264 the cpu goes to 100%

and it encodes lifetime (30fps)

[_Al_]

ok, just try raw h.264, this test is just to check if CPU goes close to 100%, BAT file:

@echo off
@x264 --crf=18 --output out.h264 input.avi
@echo+
pause

[Slind]

isn´t this the same like:

@echo off
@x264 --crf=18 --output out.264 input.avi
@echo+
pause



what I did ?

[_Al_]

out.h264 or out.h264 , the same thing, still error?

[Slind]

just out.264 works at 100%

and out.h264 at 100% too

[poisondeathray]

just out.264 works at 100%

and out.h264 at 100% too

But this is the same x264.exe that comes with megui ?

What where the FPS ? for megui , and x264 alone with the bat file ? (assuming you're not running other things as well)

Post the megui log file that you said was encoding at <50% CPU usage

[Slind]

yes, 26-30 fps

[poisondeathray]

What was the FPS with x264vfw, and megui when it was <50% CPU usage ?

If that's true, then the bottleneck is likely the other processes going on with megui (avs script, filtering etc...)

Post the megui log file




BTW - Megui's x264 is a stripped down binary (it doesn't include support for some other things, like MP4 container, other color spaces, filtering)

[Slind]

I have to do one again, I uninstalled megui, I do it as soon as I´m back on power.

But the video I tested to encode, took about 18 min. The time I tried it with megui via framserver and via AEM took about an hour. Without frameserver, well I don´t now, I only tested it for 20 seconds, to see the cpu usage.

[_Al_]

You try that signpost.avi coming from Premiere's DebugMode Frame server in that BAT.
It can give you an error frame serving RGB instead of YV12 but it will convert it to YUV anyway, so you better set YV12 serving from Premiere.

Just that it works, but sure, better habit is to load that signpost.avi into Avisynth. And x264 or any x264 frontend loads directly Avisynth script. Just for the sake of it try it and load that Avisynth script into MeGui so Megui would not do something behind your back, maybe that is what poisondeathray has on radar too.

Avisynth script is just this one line providing you set debugmode export to YV12:
Avisource("signpost.avi")

Write that line into notepad and save as any_name.avs (no gaps or foreign signs) to create avisynth script.

[jagabo]

the sourcefile is YV12 within a .avi

Uncompressed YV12? What frame size?

[Slind]

fullhd