// This program transposes a MIDI file into another key.
// "trnsp 12 < x.mid" makes a file out.midi which is like
// x.mid but an octave higher.
// "trnsp -12 < x.mid" an octave lower.

#include "h.h"
#include <stdlib.h>
#include <stdio.h>
BP bp; note * mus = 0;
int main(int argc, char * argl[]){note* music = Read("", &bp);
if(argc<2){printf("trnsp halfsteps < x.mid\n"); exit(42);}

{int v = atoi(argl[1]);
void fed(note n){
  if(n.dur < maxdur) n.o.n.freq += v; aug(n, &mus);}
printf("Transposing %s %d half steps\n", v<0?"down":"up", abs(v));
scan(fed, music, 1);
Write("", mus, &bp); return 0;}}