GTK-RecordMyDesktop is a great app for taking screen video's with sound.

However on my Fedora 20 workstation. The sound recording is atrocious. The sound coming from my head phone mic into the recording of my desktop screen video is noisy and sub-par.

To improve things I do the following:

1. Record the desktop video using gtk-recordmydesktop which ends up in a file named out-X.ogv
2. Split the audio off into a new file using ffmpeg ( ffmpeg -i “out-1.ogv” -vn -ac 2 -ar 44100 -ab 320k -f mp3 output1.mp3 )
3. Open output1.mp3 in audacity and remove the noise and re-export as a cleaned sound stream output2.mp3
4. Open pitivi and add the recordmydesktop video and the cleaned up audio and then disable the bad sound leaving the good sound
5. Re-export from pitivi into a high def video (1080p) format
6. Test video

Refs:

http://peppoj.net/2010/09/how-to-extract-audio-from-video-using-ffmpeg/