Records Xvfb screen by taking multiple screenshots and creating an mp4 with ffmpeg.

record-xvfb.sh

#!/bin/sh

# Usage example
# record-xvfb.sh /var/tmp /video $XVFBPID

xvfb_source_dir=$1
dest_dir=$2
pid=$3

echo "PID to watch: $pid"
echo "Xvfb Framebuffer directory: $xvfb_source_dir"
echo "Screen captures destination directory: $dest_dir"

rm $dest_dir/*.jpg

i=0
while kill -s 0 $pid; do
  img_name=img_$(date +"%s")_$i
  echo "Capturando imagem $img_name"
  cat "$xvfb_source_dir/Xvfb_screen0" | convert xwd:- "$dest_dir/$img_name.jpg"
  sleep 0.04
  let "i+=1" 
done

echo "Processo $pid parou"

echo "Criando video"

ffmpeg -framerate 10 -pattern_type glob -i "$dest_dir/*.jpg" -c:v libx264 "$dest_dir/video_$(date +"%s").mp4"

echo "Removendo imagens"

rm $dest_dir/*.jpg