I have about 80 compositions written in MIDI and I want to convert them in to WAVE using a sound library. So they can be played on all computers and sound the same. Is there a library that can automate this?
Preferably in C#, but other programming languages are fine too.
This is what's called a Soft Synth, you will also need a set of instrument samples if you want them the sound the same on all machines.
You may find that you will save memory if you just convert them all to wave files once and ship the wave files. A high quality instrument set can be quite large, and most of them are copyrighted as well.
I've used Timidity to do this, but that's been many years ago, and on Linux.
If they are static midi arrangements you could use a DAW with some soft synth plugins (e.g. http://www.cockos.com/reaper/ Cubase, etc and just supply wavs\mp3s with your app...?
PistonSofts's Direct MIDI to MP3 Converter. I don't think it's a library per se, but it has a command-line interface.
You can use FFMPEG to handle conversions of both Movies and Audio, including I believe MIDI to Wave. http://ffmpeg.arrozcru.org/wiki/index.php?title=Links has some basic information on the process, but basically once installed you can just run the command line process in a background process thread and raise an event once complete.
http://code.google.com/p/ffmpeg-sharp/ is wrapper built for FFMPEG and .net framework. I am sure there are probably more