I want to control the volume of the omxplayer audio output. I know omxplayer accepts '+' and '-' to change the volume but they are not useful using a slider in a GUI so my idea was to control the general volume of the Raspberry Pi but when I change the volume... nothing changes, the volume is the same as before. Any idea?
To clarify: if I change the master volume the volume bar in the task bar changes but I do not hear any change in the volume of the sound also if I set it to 0%.
