HEVC encoding using FFMPEG using 30+% of cpu

General Support / Questions Hardware Encoding
1

Hey all,

I have notice that when I’m encoding from H264 to H265 that my GPU is doing 49-50% of usage and my CPU is around 30% usage for the FFMPEG process. Can someone please help me fix FFMPEG usage on cpu when wanting only GPU hardware encode for hevc_nvenc? Or at least let me know what is going on with the CPU usage here. :smiley:

Screenshot 2021-04-23 235844
Screenshot 2021-04-23 2358441180×328 64.6 KB

Here is my profile :

[MKV HVEC - No Time Removed]
Description=WARNING: Handbrake Constant Quality encoding (18) with Nvidia HVEC.
order=ffmpeg, handbrake
AllowH264CopyRemuxing=true
FixedResolution=true
AutoDeinterlace=true
ffmpeg-UsingHardwareEncoding=True
ffmpeg-general=-threads 0
ffmpeg-video=-ss 0 -map_metadata -1 -c:v hevc_nvenc -cq 18 -rc vbr -map 0:v
ffmpeg-audio=-acodec ac3 -ab 256k -map 0:a
ffmpeg-audioac3=-acodec ac3 -ab 384k -map 0:a
ffmpeg-ext=.mp4
ffmpeg-audiodelay=skip
handbrake-UsingHardwareEncoding=true
handbrake-general=–decomb --denoise=“weak” --loose-anamorphic --verbose=2 -T -O
handbrake-video=–start-at duration:0 -e x265 -q 18
handbrake-audio=-E ffac3 -R auto -B 256 -D 0 -a 1,2,3,4,5
handbrake-audioac3=-E ffac3 -R auto -B 384 -D 0 -a 1,2,3,4,5
handbrake-ext=.mp4
handbrake-audiodelay=skip
PreConversionCommercialRemover=false

Here are my system specs:

CPU: Intel i9-9900k @ 3.60 GHz (OC 4.9 GHZ all cores).
RAM: RAM: Corsair Vengeance LPX 16GB DDR4 3200MHZ.
MOBO: Gigabit Aorus Z390 Ultra.
GPU: EVGA GeForce GTX 1080 Ti FTW3 ( 11G-P4-6696-KR ).

2

You’re also converting the audio to AC3 which consumes CPU.

3

Silly question - are there any audio transcoding engines/algos/codecs or options that also utilize the GPU?
Or is that just not a thing that will happen any time soon?

4

I’m not aware of any audio codec that has hardware encoding or decoding support in a GPU. If you don’t compress your audio it won’t use any CPU though. Well none related to decode/encode of audio.

ffmpeg-audio=-acodec copy -map 0:a
ffmpeg-audioac3=-acodec copy -map 0:a
2 Likes
5

Ah totally overlooked the audio portion of the conversation. So with the line that you sent it would do a 1:1 copy of the original source audio?

6

Correct. If you replace the lines with the ones I sent then it will do a 1:1 copy of the source audio with no conversion.

1 Like
7

@SystemIdleProcess - I made the change yet ffmpeg.exe is still using above 30% of cpu. See attached

Screenshot 2021-04-26 090924
Screenshot 2021-04-26 0909241184×1177 243 KB

8

Can you attach the conversion log? I’m more of a Handbrake guy so not sure if this is normal or not but the log might help.

9

You might be able to figure out more about what is chewing up CPU within the MCEBuddy and FFMPEG processes using Microsoft/SysInternals Process Explorer and looking at the thread stack for the thread that’s eating CPU.