How to simplify a midi file similar to the same limitations of a player piano

Question

Please bear with me because I'm very new with working with music. I've been searching for a really long time and reading the manuals of various software I've download and have not been able to figure this out.

What I'm trying to accomplish exactly is:

1. To simplify a midi file. By that I mean making the velocity/volume the same and the pitch bending removed and a way to modify the tempo.
2. All the different tracks and channels merged into one track and channel. I'm using midi editor http://midieditor.sourceforge.net/ however, if another program can accomplish this better I'd rather use that. The output has to be midi.

The end result would be a midi file with one track that if played with a piano soundfont would mimic the results of a piano roll on a real simple foot powered player piano. This is my first question here on music so sorry in advance if I'm using the wrong terminology I'm open to suggestions on how to improve my question. I will respond to any comments quickly and edit my question as necessary.

Answer 1

I once wrote a program in C++ which parses, manipulates and writes Midi-files. It was one of my first programs I wrote, thus the code is probably not the best - but as far as I remember, it worked quite well.

If you have programming skills, I could send you the source-code. The things you mention above, should be implemented quite easily, if I remember my code correctly.