useful_scripts/record_screen.sh

#!/bin/bash
export LD_LIBRARY_PATH=/usr/local/lib 
ffmpeg -vsync 0 -hwaccel cuda -hwaccel_output_format cuda     `# we need nvidia acceleration because of low fps without it` \
-r 30 -video_size 640x480 -i /dev/video0  `# this is camera` \
-f alsa -i default -async 1                                   `# this is audio. Why not pulse? Nvidia?` \
-c:v h264_nvenc                                     `# this is video codec` \
video.mp4 # output file
#-filter_complex 'overlay=main_w-overlay_w:main_h-overlay_h' `# this is overlay` \
#-f x11grab -framerate 30 -video_size 1920x1080 -i :0         `# this is screen` \