Make sure microphone is properly plugged in. You may also test your recording settings using "sound recorder" on your Ubuntu.

Now, execute the following command on terminal by replacing 1366x786 by your screen resolution.

avconv -f alsa -i pulse -f x11grab -r 30 -s 1366x768 -i :0.0 -vcodec libx264 -preset ultrafast -threads 4 -y myscreencast.mp4

If you use avconv regularly of making screencast you would like to avoid typing above command each time (in that case, do the following) :

Save the script given below in ~/Videos/ with filename screencast

#!/bin/sh

echo "Enter the output file name: "; read name



fullscreen=$(xwininfo -root | grep 'geometry' | awk '{print $2;}')



avconv -f alsa -i pulse -f x11grab -r 30 -s $fullscreen -i :0.0 -vcodec libx264 -preset ultrafast -threads 4 -y $name

Do, chmod +x screencast

Now, double-click on screencast file and "Run in Terminal"
Enter the name of video you want to make(filename and extension eg:myvideo.mkv or myvideo.mp4).

Finally, on completing your screencast, do ^C (contol+c) in terminal.

Your video will be saved in ~/Videos/
Bingo!!!