[Feature] Per track and per playlist volume adjustments

[Haravikk]

One issue I encountered when using Kenku FM yesterday was that some of my music was a lot quieter than others, so I frequently had to dip into the app to adjust the overall volume to compensate.

While I know there are some tools I could use to balance the volume, it would be nice to not have to rely on external tools to pre-process everything.

What I would like to see added is a volume adjustment slider for both individual tracks and entire playlists (maybe soundboards too?). If set to the middle (zero) position there will be no adjustment except for the master volume, otherwise the volume is adjusted up or down by a percentage based on how high or low the slider is set. If there is both a track adjustment, and a playlist adjustment, then these should be combined.

The idea is that by boosting quiet tracks and reducing noiser ones it should be possible to get them all at roughly the same level so the master volume should not need to be changed. Meanwhile the playlist adjustment would make it possible to still have some music louder or quieter intentionally for ambience, combat and so-on.

In future it would also be great if per-track volume adjustments could be done automatically when they are added, i.e- Kenku FM would measure the minimum, average and maximum median volume levels and use these to set an automatic track adjustment that the user can override later if they wish. This way all music should be at a similar overall volume by default.