I'm using ffmpeg over 3 years now mainly I'm doing live broadcasting on my site , currently I'm preparing to do 5 livebroadcast on the same time using my VPS server CPU E3-1240 v5 OpenVZ Since I'm only allowed to use 1 vCore CPU usage jumps high very fast . What I ask , I know H264 algorithm based on calculation of previous frame (ref frame) and I frame So I tried -copyinkf and -break_non_keyframes 1 with no effect on the speed BTW here is my main broadcast command :-

ffmpeg -re -i "http://sorce.m3u " -s 720x406 -r 23.976 -vcodec libx264  -profile:v high444  \ 
-crf 35 -copyinkf - break_non_keyframes 1 -preset slow -acodec libfdk_aac \
-profile:a aac_he_v2 -b:a 8k -map_metadata -1 -f flv rtmp://localhost/hls/live 

Current I use -preset slow to improve image quality little bit CPU usage 60% even with preset fast CPU usage were 47% -preset veryfast CPU-usage 35%

  • What's wrong with the faster presets?
    – Gyan
    Jan 29 '19 at 19:15
  • it's peak the CPU usage sometime goes up 50% which will kill the tow process , and their is huge quality drop, this setting is the lowest I can get for ~265kbpsbroadcast ,,+ I test it without the extra -copyinkf flags with no different at all , BTW I'm using crf method with value of 35
    – Salem F
    Jan 29 '19 at 22:04
  • There is no way to use less CPU without reducing quality. If there was, that setting would be turned on by default.
    – SlimSCSI
    Jan 30 '19 at 17:06
  • I'm using low pic size 720x406 with low bitrate , on my laptop cpu its run it fast , but the server VPS limited to 1 vCore so my code above will uses more cpu resources .
    – Salem F
    Jan 30 '19 at 18:23
  • Alright I found out what's was peak CPU usage -profile:v high444 once I remove it the cpu usage drooped dramatically to less then 30%
    – Salem F
    Jan 30 '19 at 20:05

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