Linux Screencast Recipe

2009-09-29
2013-02-09
  • #Linux Screencast Recipe

    First, install and start . This program is a GUI frontend to the . It allows to easily connect the audio output from one program to the input of another one.

       
        # apt-get install qjackctl jackd

       
        # zypper install jack
        # zypper install qjackctl

    Configure QJackCtl ("Setup" button) to use the ALSA audio driver, and some "hw:" interface. Don't worry too much about the latency for now, use for instance frames=1024 and periods=3 or even bigger values.

    Then, install and start . This program is a GUI frontend to the   MIDI synthesizer. The synth renders MIDI events into audio.

       
        # apt-get install qsynth fluidsynth
       
       
        # zypper install fluidsynth
        # zypper install qsynth

    Now, you need a SoundFont. I've used the  SoundFont by S. Christian Collins. Download the package, and unpack the contents into some folder of your home directory. Alternatively, you can install some other soundfont provided by your distro.

       
        # apt-get install fluid-soundfont-gs fluid-soundfont-gm

    Configure QSynth, pressing the "Setup" button. In the MIDI tab, select the alsa_seq driver. On the Audio tab, select the jack
    driver. Finally, on the "SoundFonts" tab, open the SoundFont file that you have installed.

    Download and install  and

       
        # apt-get install vmpk mscore

    Open VMPK, menu Edit->Connections. In "Output MIDI Connection", select "FLUID Synth…", and play some keys with your mouse and the computer's keyboard. You should hear sounds now. Press the "Connect" button in QJackCtl, and look to the Audio and ALSA tabs, showing some connections between your running programs.

    Start MuseScore, menu Edit->Preferences, select the "I/O" tab and check the "use MIDI output" option. Restart mscore, and now go again to the "Connections" tool of QJackCtl, ALSA tab. Select the output port of MuseScore on the left, and the VMPK input on the right and press the "connect" button. Select again the MuseScore output port and FLUID Synth on the right side and press the "connect" button a second time. Now, you can press the "start sequencer play" button on MuseScore. You should hear the sound from QSynth, and watch the played notes in VMPK.

    Install  . There are Gtk+ and Qt GUI frontends for this program.

       
        # apt-get install recordmydesktop

    Finally, use recordMyDesktop to record the sound (from Jack) and video to make the screencast. Enjoy!

      : http://qjackctl.sourceforge.net
      : http://jackaudio.org
      : http://qsynth.sourceforge.net
      : http://fluidsynth.resonance.org/trac
      : http://www.schristiancollins.com/generaluser.php
      : http://vmpk.sourceforge.net
      : http://www.musescore.org
      : http://recordmydesktop.sourceforge.net