How to reduce CPU usage when it reaches 100% during video reencoding

Question

I'm using the following command to change a video:

ffmpeg -loop 1 -i max.png -i video.mp4 -i 1.flv -filter_complex "
[1:v]scale=1280x720,setpts=PTS/1.15[a];[2:v]scale=750:420,setpts=PTS/1.15,pad=iw+5:ih+5:2:2:color=black[b];[0:v][a]overlay=10:(main_h/2)-(overlay_h/2)[a]; [a][b]overlay=(main_w-overlay_w-0.1): (main_h-overlay_h-0.1):shortest=1,setdar=16/9[video],[1:a][2:a]amix=inputs=2:duration=shortest,atempo=1.15,volume=1.6,equalizer=f=1000:width_type=o:width=1:g=1,equalizer=f=1000:width_type=o:width=1:g=2,equalizer=f=1000:width_type=o:width=1:g=3,equalizer=f=1000:width_type=o:width=1:g=4,equalizer=f=1000:width_type=o:width=1:g=5,aecho=0.8:0.88:6:0.1,aecho=0.8:0.88:6:0.2,aecho=0.8:0.88:6:0.3,bass=g=3:f=110:w=1,bass=g=3:f=110:w=2,bass=g=3:f=110:w=3,pan=stereo|c0<c0+0*c1|c1<c0+0*c1,aeval=-val(0)|-val(1)[audio];[video][audio]concat=n=1:v=1:a=1
" -vcodec libx264 -pix_fmt yuv420p -r 30 -g 60 -b:v 1000k -minrate 1000k -maxrate 1000k -profile:v main -level 3.1 -acodec libmp3lame -b:a 228k -ar 44100 -preset fast output1.mp4

As you can see the CPU usage is pretty high and I would like to reduce it to about 30-40%. But I don't know how to achieve this?

Solution 1

1. task manager
2. then detail tab
3. right click on ffmpeg.
4. Select affinity
5. uncheck all the cores except 1.

What it to use more check at 2nd one. Keep checking boxes until you get the desired results.

Solution 2

Try -threads 2 parameter on your FFMPEG launch script, you can limit used threads by using that flag.

Comments

[cybernard]

If you reduce the CPU usage it will take that much longer to complete. It is designed to run at 100% so it completes in the minimum amount of time.

[Seth]

You might want to include some details about your hardware as it might be relevant (CPU and GPU). You might be able to offload some of the work to the GPU (not sure about that) or use what's detailed in How can I limit FFMpeg CPU usage?.

[Đỗ Mạnh Trí]

Thanks guy. One more. If I want to use GPU (I have 8Gb RAM) to render, How I can do that ?

[cybernard]

@ĐỗMạnhTrí trac.ffmpeg.org/wiki/HWAccelIntro That should get you started.