Improve audio support

[Rinnegatamante]

This is a complete TODO list regarding audio support:

BGM (Musics):

• OGG support (partially implemented)
• MP3 support
• MIDI support
• BGM_Pitch implementation
• BGM_GetTicks implementation

Generic:

• Write a proper audio wrapper which uses dsp::DSP service if csnd:SND is unavailable.

[Ghabry]

Just to keep the people only following github and not the forum informed:
MP3 and MIDI support will be provided by the EasyRPG devs because the way how MP3/MIDI are currently supported is bad.

And BGM_GetTicks is a MIDI-only feature btw.

[Rinnegatamante]

BGM_Pitch produces a lot of bugs atm:

On csnd:SND:

1. When called it seems to not be able to resume correctly sometimes, in the specific it seems to follow this pattern:

1st call: BGM playstate is paused but not in logic streaming (so it will continue the streaming but you'll not listen anything like if volume is 0) at the end of BGM_Pitch.
2nd call: BGM is fine.
3rd call: Same as 1st call.
...

2. Looks like it produces random system crashes if used with pretty high samplerates (?)
3. With high samplerates (like a 44100 samplerate BGM pitched with values >100) audio thread is not fast enough to correctly stream the song resulting in a corrupted BGM playback.

[Rinnegatamante]

BGM_Pitch finally fixed :P

[gnmmarechal]

awesome, updated the testbuild for the updater with the latest commit.

[Ghabry]

You wrote a while ago that OGG does not work correctly.
Maybe this helps: Ghabry/easyrpg-player@9ef8469#diff-5ae40f1d5e418f1297a3df932be3d5b7L24

[Rinnegatamante]

Not at all, OGG doesn't work correctly only for BGMs cause it needs a different audio streaming function (since vorbisidec doesn't give you static PCM buffer sizes) and cause apparently secondary thread just crashes when used for BGM oggs. Sounds are working perfectly.