Requirements for midi playback support

[Ancurio]

A library to support midi files in mkxp ideally:

• accepts events passed with a delta time (not real time)
• renders audio chunks on demand
• works fine with longer pauses in between requests to generate chunks
• has an option to apply a pitch factor to each processed note event
• (optional) has static utility functions to parse events from the bytestream

The requirement of manually feeding events is there so the "0x6F" control value change event, which marks the loop start, can be detected, and event parsing can be restarted from this position in the byte stream (very cheap, as just a file seek).

libfluidsynth

• API for loading sound fonts present
• Is a real time synthesizer, so doesn't really fit the desired model (must be fed events/notes in real time)
• Pitch on each note event can be manipulated
• Has a glib2.0 dependency

  SDL_Sound / timidity fork

• Haven't spotted any API for feeding events directly yet
• Also no API spotted for loading custom sound fonts (maybe via the config file??)

  WildMidi

• Uses GUS patches (no soundfont support)
• Can open midi files (either by filename, or as memory buffer)
• No way to feed events directly
• Not sure if global pitch settable

[fdelapena]

You can consider WildMIDI too, but it does not support soundfonts, only GUS patches like old Timidity.

Some fluidsynth performance notes: https://github.com/EasyRPG/Player/issues/17

Timidity++ does support SF2 and yes, can be set up via .cfg with soundfont "foo bar.sf2". But note Timidity++ is more intended to be used as a server.

[Ancurio]

Thank you very much for the notes! I will look into WildMIDI.

To be fair, I don't think there really exists a library that does what I want (realtime independent sample rendering of midi event streams), because almost every software synth is written for use in real time with electric keyborads etc.

I have to experiment a bit more with fluidsynth to see if there's a workaround possible.

[euna8815]

Why not SDL_mixer? It is also part of SDL and can play MIDI files.

[Ancurio]

Why not SDL_mixer? It is also part of SDL and can play MIDI files.

If you read the specific requirements I listed above, you'll find that SDL_mixer fulfills none of them. Besides, it's a different class of framework alltogether, as it handles both decoding of sound data and submission to the audio hardware; the latter part is already handled by OpenAL in mkxp.

[Ancurio]

Just wanted to update that I might have been misinformed on the way fluidsynth works, and am now doing some experiments with it.

[Ancurio]

Implemented: 751fdc599e241c1f1c4c20513787e5f3706f21cc.