MIDI to PCM
It seems like a reasonable thing to do for a number of reasons (post-processing, file format conversion, etc.), but I cannot see any obvious way to take a MIDI sequence in Java and turn it into a PCM sequence. Play, yes, but not convert.
I know it's possible to, for example, play the MIDI file and physically connect the speaker socket to the microphone socket, but there must be a software-only way of doing it, and there should be a pure-Java way of doing it.
I'm very new to Java, but not new to MIDI or software synths, here are my $0.02
The MIDI file can be played in two ways (that I can think of):
1. by using a SoundFont (actually a collection of pieces of PCM data, to be mixed an glued together and saved as one PCM "block?")
2. by using one or many "PCM generators", actually software synthesizers that render the PCM data at runtime, and also a mixing method to mix the outputs of up to 16 synths into a stereo PCM file.
Maybe it's easiest if you choose the SoundFont way, use a GM (General Midi) SoundFont and only accept GM MIDI files to get started.
Or you could have a look at jvstwrapper dot sourceforge dot net :)