WildMidi volume is now too low

[Mimigris]

If a a wildmidi.cfg file alongside its instruments files are put next to a Player, that WildMidi is set as the configuration in the in-game settings and that a MIDI music has to play, the music will not make any sound. This issue wasn't present in 0.8.1.1.

[Mimigris]

Update: I went on checking with a random game on 3DS (Wadanohara), and noticed there was music while using WildMidi, but that its volume was extremely low. I went back on checking on Windows with the continuous build, and it's actually the same thing here, the music plays but at a volume way too low compared to the other MIDI settings and the volume of sound effects (to be able to hear the music, I have my Windows volume to 100 while I usually stay at around 20).

[VannevarXbox]

Can confirm, I've been experiencing this with my Xbox port since I started on it (~December or so). I'll update if I find anything

[VannevarXbox]

@Desdaemon

This commit appears to have introduced this issue: 2b8564c

Testing with Fluidlite, in GenericAudio::Decode vleft and vright have a value of 1 at EasyRPG config volume of 100. But Wildmidi (which doesn't support MIDI messages) triggers the code in AudioDecoderMidi::ApplyLogVolume(), and results in volume.left_volume and volume.right_volume (and as a result vleft and vright) being set to around 0.02.

[Ghabry]

The log scale itself is correct to how RPG_RT (and Direct Sound) do it.

Midi is internally using a log scale so we use linear their.

So maybe using linear for Wildmidi works?