Originally Posted by chrone
Just tested this out with no luck. Audio was still passed through the speaker though system sound was disabled as shown on the status bar - vibrate only.
Perhaps there's a bug on the L preview and not MX Player?
Sent from my Nexus 5
I think you have totally misunderstood. Android have individual volume controls for different activities. In my knowledge almost all android systems, If you set on mute/vibrate, it will basically mute only all alert tones like System, Notification, Alarm & Ring Volumes. It does not mute media volume. There is no such native global volume control that can block media volume. There are some custom roms like cyanogen mod which can block volume volume keys. But, that will not also work with media volume.
So, It's not a MX Player bug. It's a lack of android feature.
Look at the volume control settings screenshot which is taken while my mobile is set on mute mode.