Does anyone know if there is a free/cheap MIDI player/synthesizer library that I can incorporate into my iPhone application?
As I understand it the iPhone doesn't have native support for MIDI playback.
To work around this limitation I've created a bank of .caf sound samples that I playback myself but I'd really like to improve the implementation and use MIDI if possible.
Any advice would be greatly appreciated.
Since 10 october of 2011, that is since iOS5, Apple has started delivering basic API for midi files playback. The API is called MusicPlayer along with MusicSequence Check this out :
By setting up an appropriate Audio Unit Processing Graph you can output the sound you like.
Look at TiMidity++; it looks like something that should be portable to the iPhone platform.
TiMidity++ is a software synthesizer. It can play MIDI files by converting them into PCM waveform data; give it a MIDI data along with digital instrument data files, then it synthesizes them in real-time, and plays. It can not only play sounds, but also can save the generated waveforms into hard disks as various audio file formats. TiMidity++ is a free software, distributed under the terms of GNU general public license.
Many people have ported TiMidity++ into various platforms; FreeBSD, NetBSD, many Linux distributions, Windows (and/or Cygwin environment), and Mac OS are known to have their own versions.
There is a commercial library available from Crimson Technology
I have never used it so I can't vouch for it's quality.
This is a library I've used for MIDI synthesis in Android: https://code.google.com/p/android-midi-lib/
Although it can't be used for iOS, I think you(and anyone who's interested) can still take a look at the implementation of the MIDI file format(i.e. how bytes are written to a .mid file) and possibly implement a MIDI library yourself.
来源：https://stackoverflow.com/questions/449057/midi-player-synthesizer-library-for-the-iphone