get mplayer to start with a default volume other than 25%
Solution 1:
You can run mplayer with the -af flag:
mplayer -af volume=10:1
where the value 10 means the sound is amplified by 10dB
To set this, edit the mplayer configuration file:
~/.mplayer/config
add the option:
af=volume=10:1
The af flag alters the hardware volume. If this doesn't work, you can try specifying the software mixer, and altering the software volume with the options:
softvol=yes
softvol-max=1000
Solution 2:
The -volume option sets the volume between 0 and 100.
mplayer -volume 40 MyMusicVideo.mp4