ffmpeg record desktop command (audio-video sync issue)

ffmpeg -vsync cfr -fflags nobuffer -f x11grab -s $INRES -r $FPS -i :0.0 \
 -f pulse -ar 44100 -i default \
 -vcodec libx264 -pix_fmt yuv420p -preset ultrafast -x264opts fps=$FPS -s $OUTRES \
 -acodec libmp3lame -af aresample=async=1000:min_hard_comp=0.100000 \
 -threads 1 -b:v $BITRATE -fflags nobuffer  \
 -f flv test.flv