Screen Capture in Linux

Video Capture of Screen in Linux

• -video_size should be used according to your screen resolution.

  • Screen resolutioon can be found as follows:

  X=$(xrandr --current | grep '*' | uniq | awk '{print $1}' | cut -d 'x' -f1)
  Y=$(xrandr --current | grep '*' | uniq | awk '{print $1}' | cut -d 'x' -f2)
  echo "$X" x "$Y"
  

  • If you use more than one screen, the result will be like this X1 X2 ... Xn x Y1 Y2 ... Yn and you should use that as a pair of (X1 x Y1), (X2 x Y2), …, (Xn x Yn).
• -framerate specifies the frame rate, i. e. how many frames of video are recorded in a second. If you need another frame rate, use another number than 30. The lowest allowed framerate is 20.
• -f x11grab is what actually tells FFmpeg to record your screen. You shouldn’t change that.
• echo $DISPLAY command allows you to define what will be written after -i :. It can be 0 (zero) or something else.
• -f pulse tells FFmpeg to grab the input from PulseAudio, which is your sound server.
• -ac 2 specifies the number of audio channels. If you receive an error like: “cannot set channel count to 2 (Invalid argument)”, you should change that to 1.
• pacmd list-sources command allows you to define what will be written after -ac -2 -i. It can be 1 (one), 2 (two) or something else.
• -c:v libx264 is encoding options.
• -t 00:00:10 determines the record time (in that case it is 10 seconds).
• “date '+%Y-%m-%d_%H.%M.%S'.mp4” defines what will be the name (as a datetime format) and the type of the output file.

With System Sounds

ffmpeg -video_size 1920x1080 -framerate 30 -f x11grab -i :1.0+0,0 -f pulse -ac 2 -i 1 -c:v libx264 `date '+%Y.%m.%d-%H.%M.%S'`.mp4


ffmpeg -video_size 1920x1080 -framerate 30 -f x11grab -i :1.0+0,0 -f pulse -ac 2 -i 1 -c:v libx264 -t 00:00:10 `date '+%Y.%m.%d-%H.%M.%S'`.mp4

With Microphone

ffmpeg -video_size 1920x1080 -framerate 30 -f x11grab -i :1.0+0,0 -f pulse -ac 2 -i 2 `date '+%Y.%m.%d-%H.%M.%S'`.mp4

Audio Capture of Screen in Linux

• pactl list short sources command allows you to define what will be written after -i.

With System Sounds

ffmpeg -f pulse -i alsa_output.pci-0000_00_1f.3.analog-stereo.monitor -ac 2 `date '+%Y.%m.%d-%H.%M.%S'`.m4a

With Microphone

ffmpeg -f pulse -i alsa_input.pci-0000_00_1f.3.analog-stereo -ac 2 `date '+%Y.%m.%d-%H.%M.%S'`.m4a

NOTE: CTRL + C lets you to stop recording. NOTE: alsamixer command lets you to visually arrange sound settings.

Ref: https://www.wikihow.com/Record-Your-Desktop-Using-FFmpeg-on-Ubuntu-Linux

NOTE: If you face some problem while trying to play captured video or audio on windows, you can visit Codec Guide and download K-Lite Codec Pack Mega on your computer which will most probably solve your problem.