[Feature request]: Mono audio option

[vzhd1701]

Could you add a MONO option choice for every single player to enable mono audio & also maybe a MONO audio option in the settings itself to set all playing streams to Mono audio as default. Now you will ask why mono right, because some streams running just with one audio channel left or right or some channel is louder or quieter whats really bad to hear streams on that way and in such cases I need to switch to mono audio to make both channels same good like you can do in VLC too.

Originally posted by @Dean-Corso in https://github.com/vzhd1701/gridplayer/issues/15#issuecomment-1167811709

[vzhd1701]

I created a audio mp3 file with total silence on left channel and music on right channel. Now I tried to execute VLC itself with commandline and found out that this commandline does work as MONO "--stereo-mode=7". Just use value 7 does set VLC to MONO in audio options. Value 7 is not documented...

      --stereo-mode={0 (Unset), 1 (Stereo), 2 (Reverse stereo), 3 (Left), 4 (Right), 5 (Dolby Surround), 6 (Headphones)} 
                                 Stereo audio output mode

....but if you use 7 with VLC as commandline then see into audio / stereo modus / Mono <--- set. So you can verify that.

Originally posted by @Dean-Corso in https://github.com/vzhd1701/gridplayer/issues/15#issuecomment-1186016954

[vzhd1701]

Added in version 0.5.0.