Note: Some of the following commands work when logged-in locally or via VNC-Viewer but does not work when logged-in remotly (SSH). In that case set the shell environment parameter DISPLAY to ":0.0" (type 'DISPLAY=:0.0' in logged-in shell).

Play ogg/oga files:

(1) (a) echo ogg123 |at now (b) ogg123 Note: 'DISPLAY=:0.0' is needed

Play mp3 files:

(1) mpg123

Play wav files:

(1) On Default Sound Card (hw:0) aplay Note: 'DISPLAY=:0.0' is needed (or) aplay -D hw:0

Change Audio Mixer Setting:

(1) In CLI, using interactive menu alsamixer Note: 'DISPLAY=:0.0' is needed (2) In CLI, non-interactive (a) set playback volume to X% of maximum [Range 0-100%] amixer set Master playback % e.g.: amixer set Master playback 90% (b) increment playback volume by X% of maximum [add '+' sign] amixer set Master playback %+ e.g.: amixer set Master playback 5%+ (c) decrement playback volume by X% of maximum [add '-' sign] amixer set Master playback %- e.g.: amixer set Master playback 5%- (d) Without mentioning the soundcard (automatically 'Default' is used) amixer set Master playback % Note: 'DISPLAY=:0.0' is needed

Pulseaudio for multiple users:

See: http://billauer.co.il/blog/2014/01/pa-multiple-users/ When we login into a desktop user, the audio is only accesseble only to that user. This procedure will enable access to other users while loging-in to that user through terminal, while logged into the default desktop user via GUI. (1) As default desktop user (a) If not done already, creating a custom configuration for the default desktop user mkdir ~/.pulse/ cp /etc/pulse/default.pa ~/.pulse/ (b) Enable pulse audio to accept connections through loop-back TCP port load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1 (c) Restart pulse audio pulseaudio -k # kill pulseaudio -D # start daemon (2) As another user (for which you want to enable pulse audio access concurrently with default desktop user) (a) Specify the access method mkdir ~/.pulse echo "default-server = 127.0.0.1" > ~/.pulse/client.conf Note: If using Tor browser-bundle, firefox runs in "/Browser/" directory and is its home directory. So create the ".pulse/client.conf" in this directory. (b) Now application running as this user (changed via terminal {using 'su' or 'ssh'} or switch user via GUI) can access audio. e.g.,start browser via terminal through following command firefox --display=:0 (or) google-chrome --display=:0

Pulseaudio Dynamic Range Compression

See: https://github.com/gotbletu/shownotes/blob/master/pulseaudio-dynamic-range-compression.md http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#tth_sEc2.92 https://www.youtube.com/watch?v=91qs3fux5HY https://askubuntu.com/questions/31580/is-there-a-way-of-leveling-compressing-the-sound-system-wide (1) Install dynamic-range-compression plugin (ladspa-swh-plugins) and its dependencies yum install pulseaudio pavucontrol ladspa-swh-plugins (2) If not done already, creating a custom configuration for the default desktop user mkdir ~/.pulse/ cp /etc/pulse/default.pa ~/.pulse/ (3) Append following lines to ~/.pulse/default.pa .ifexists module-ladspa-sink.so .nofail load-module module-ladspa-sink sink_name=dynamic-range-compression plugin=sc4m_1916 label=sc4m control=1,1.5,401,-30,20,5,12 .fail .endif (4) Reboot Pulse-Audio pulseaudio --kill pulseaudio --start (5) Now play some audio, then open pavucontrol and change the stream to the LADSPA compressor. Or set it as default output option