Makefile

CC=gcc

all:mid2mml

mid2mml:mid2mml.o midi.o
	$(CC) -o $@ mid2mml.o midi.o

.c.o:
	$(CC) -c $<

mid2mml.c

#include<stdio.h>
#include"midi.h"

int main(int argc,char *argv[]){
	Midi *m;
	int i;
	if(argc<1){
		fprintf(stderr,"usage:%s file\n",argv[0]);
		return 0;
	}
	m=newMidi();
	loadMidi(m,argv[1]);
	//showMidi(m);
	for(i=0;i<m->sh->tracks;i++)showTrackData(m,i);
	terminateMidi(m);
	return 0;
}

midi.c

#include "midi.h"

void convEndian(char *c,int s){int i,l=--s>>1;for(i=s;i>l;i--){c[s-i]^=c[i];c[i]^=c[s-i];c[s-i]^=c[i];}}
Midi *newMidi(){
	Midi *m;
	m=(Midi *)malloc(sizeof(Midi));
	m->fh=(FileHeader *)malloc(sizeof(FileHeader));
	m->sh=(SmfHeader *)malloc(sizeof(SmfHeader));
	m->th=NULL;
	m->td=NULL;
	return m;
}
void terminateMidi(Midi *m){
	int i;
	if(m->td!=NULL){
		for(i=0;i<m->sh->tracks;i++)if((m->td+i)->data!=NULL)free((m->td+i)->data);
		free(m->td);
	}
	if(m->th!=NULL)free(m->th);
	if(m->sh!=NULL)free(m->sh);
	if(m->fh!=NULL)free(m->fh);
	free(m);
}
void loadMidi(Midi *m,char *filename){
	FILE *fp;
	int i;
	if((fp=fopen(filename,"rb"))==NULL){fprintf(stderr,"loadMidi:file open error\n");exit(0);}
	fread(m->fh,sizeof(FileHeader),1,fp);
	convEndian((char *)&m->fh->size,sizeof(m->fh->size));
	fread(m->sh,sizeof(SmfHeader),1,fp);//midiヘッダ読み込み
	convEndian((char *)&m->sh->format,sizeof(m->sh->format));
	convEndian((char *)&m->sh->tracks,sizeof(m->sh->tracks));
	convEndian((char *)&m->sh->timebase,sizeof(m->sh->timebase));
	m->th=(TrackHeader *)malloc(sizeof(TrackHeader)*m->sh->tracks);
	m->td=(TruckData *)malloc(sizeof(TruckData)*m->sh->tracks);
	for(i=0;i<m->sh->tracks;i++){
		fread((m->th+i),sizeof(TrackHeader),1,fp);
		convEndian((char *)&(m->th+i)->size,sizeof((m->th+i)->size));
		(m->td+i)->size=(m->th+i)->size;
		(m->td+i)->data=(char *)malloc((m->td+i)->size);
		fread((m->td+i)->data,(m->td+i)->size,1,fp);
	}
	fclose(fp);
}
void showMidi(Midi *m){
	int i;
	fprintf(stderr,"[File]\n");
	fprintf(stderr,"checksum:%c%c%c%c\n",m->fh->chk[0],m->fh->chk[1],m->fh->chk[2],m->fh->chk[3]);
	fprintf(stderr,"SMF header size:%d\n",m->fh->size);
	fprintf(stderr,"[SMF]\n");
	fprintf(stderr,"midi - format%d\n",m->sh->format);
	fprintf(stderr,"%dtracks\n",m->sh->tracks);
	fprintf(stderr,"timebase : %d\n",m->sh->timebase);
	for(i=0;i<m->sh->tracks;i++){
		fprintf(stderr,"[Track%d]\n",i);
		fprintf(stderr,"checksum:%c%c%c%c\n",(m->th+i)->chk[0],(m->th+i)->chk[1],(m->th+i)->chk[2],(m->th+i)->chk[3]);
		fprintf(stderr,"Track data size:%d\n",(m->th+i)->size);
	}
}
void showTrackData(Midi *m,int n){
	char *p,*s,**rp;
	int l,delta,count=0,time=0,flush=0,octave=DEFAULT_OCTAVE;
	unsigned char stat,rstat;
	rp=&p;p=s=(m->td+n)->data;
	l=(m->td+n)->size;
	while(p-s<l){
		delta=getVariableLengthParam(rp);
		count+=delta;
		time+=delta;
		stat=getByte(rp);
		//fprintf(stderr,"[%8d]@%8d(+%8d)-[%2x]",p-s,time,delta,stat);
		switch(stat){
			case 0xf0:
				flush=getExclusiveData(rp,count);
				break;
			case 0xff:
				flush=getOperationData(rp,count,m->sh->timebase);
				break;
			default:
				if(stat<0x80){stat=rstat;p--;}
				flush=getCommonData(rp,count,stat,&octave,m->sh->timebase);
				break;
		}
		if(flush==1)count=0;
		rstat=stat;
	}
}


int getConstantLengthParam(char **rp,int n){
	char *p=*rp;
	int value=0;
	while(n-->0)value=(value<<8)+(unsigned char)*p++;
	*rp=p;
	return value;
}

int getVariableLengthParam(char **rp){//可変長表現の取得(0x80以上で次を読む)
	char *p=*rp;
	int value=0,temp=0;
	do{
		temp=(unsigned char)*p++;
		value=(value<<7)+(temp&0x7F);
	}while(temp&0x80);
	*rp=p;
	return value;
}

int getByte(char **rp){
	return 0+(unsigned char)*(*rp)++;
}
void skipBytes(char **rp,int n){
	*rp+=n;
}

void printString(char **rp,int n){
	char *p;
	p=(char *)malloc(sizeof(char)*(n+1));
	strncpy(p,*rp,n);
	p[n]=0;
	printf(" %s ",p);
	*rp+=n;
	free(p);
}

int gcd(int a,int b){
	while(a&&b){
		if(a>b){
			a=a%b;
		}else{
			b=b%a;
		}
	}
	return a+b;
}

int putNoteData(int *octave,int notenum,int span,int timebase){
	int s=span,d=timebase*4,o=notenum/12,g;
	while(o>*octave){printf("<");(*octave)++;}
	while(o<*octave){printf(">");(*octave)--;}
	while(s){
		g=gcd(s,d);s/=g;d/=g;s--;
		printf("%s%d%s",NOTENAME[notenum%12],d,s?"&":"");
	}
	return 0;
}

int putRestData(int span,int timebase){
	int s=span,d=timebase*4,g;
	while(s){
		g=gcd(s,d);s/=g;d/=g;s--;
		printf("r%d",d);
	}
	return 0;
}

int getCommonData(char **rp,int count,int stat,int *octave,int timebase){
	int data1,data2;
	switch(stat&0xf0){
		case 0x80:
			data1=getByte(rp);
			data2=getByte(rp);
			//fprintf(stderr,"NoteOff\n");
			//それまでは音符だった。音を出さなくてはならない
			putNoteData(octave,((stat&0x0f)==DRUM_CH)?DRUM_NOTE:data1,count,timebase);
			return 1;
		case 0x90:
			data1=getByte(rp);
			data2=getByte(rp);
			if(data2>0){
				//fprintf(stderr,"NoteOn\n");
				//それまでは休符だった。休符を発行しなくてはならない
				putRestData(count,timebase);
			}else{
				//fprintf(stderr,"NoteOff\n");
				//それまでは音符だった。音を出さなくてはならない
				putNoteData(octave,((stat&0x0f)==DRUM_CH)?DRUM_NOTE:data1,count,timebase);
			}
			return 1;
		case 0xa0:
			data1=getByte(rp);
			data2=getByte(rp);
			//fprintf(stderr,"PolyAfterKey\n");
			return 0;
		case 0xb0:
			data1=getByte(rp);
			data2=getByte(rp);
			if(data1==0x7e)skipBytes(rp,1);
			//fprintf(stderr,"ControlChange\n");
			return 0;
		case 0xc0:
			data1=getByte(rp);
			//fprintf(stderr,"ProgramChange\n");
			return 0;
		case 0xd0:
			data1=getByte(rp);
			//fprintf(stderr,"Poly\n");
			return 0;
		case 0xe0:
			data1=getByte(rp);
			data2=getByte(rp);
			//fprintf(stderr,"Pitchbend\n");
			return 0;
	}
	return 0;
}

int getExclusiveData(char **rp,int count){
	int size;
	size=getVariableLengthParam(rp);
	skipBytes(rp,size);
	//fprintf(stderr,"ExclusiveData\n");
	return 0;
}
int getOperationData(char **rp,int count,int timebase){
	int type,size,data;
	type=getByte(rp);
	size=getVariableLengthParam(rp);
	switch(type){
		case 0x01:
			//fprintf(stderr,"TextEvent\n");
			putRestData(count,timebase);
			printString(rp,size);
			return 1;
		case 0x02:
			//fprintf(stderr,"CopyRight\n");
			skipBytes(rp,size);
			return 0;
		case 0x03:
			//fprintf(stderr,"SequenceName\n");
			skipBytes(rp,size);
			return 0;
		case 0x04:
			//fprintf(stderr,"InstrumentName\n");
			skipBytes(rp,size);
			return 0;
		case 0x05:
			//fprintf(stderr,"Iyric\n");
			skipBytes(rp,size);
			return 0;
		case 0x06:
			//fprintf(stderr,"Marker\n");
			skipBytes(rp,size);
			return 0;
		case 0x07:
			//fprintf(stderr,"QueuePoint\n");
			skipBytes(rp,size);
			return 0;
		case 0x08:
			//fprintf(stderr,"ProgramName\n");
			skipBytes(rp,size);
			return 0;
		case 0x09:
			//fprintf(stderr,"DeviceName\n");
			skipBytes(rp,size);
			return 0;
		case 0x20:
			//fprintf(stderr,"ChannelSelect\n");
			skipBytes(rp,size);
			return 0;
		case 0x2F:
			//fprintf(stderr,"EndOfTrack\n");
			skipBytes(rp,size);
			printf(";\n");
			return 0;
		case 0x51:
			//fprintf(stderr,"Tempo\n");
			putRestData(count,timebase);
			data=getConstantLengthParam(rp,size);
			printf("t%d",60000000/data);
			return 1;
		case 0x58:
			//fprintf(stderr,"TimeSignature\n");
			skipBytes(rp,size);
			return 0;
		case 0x59:
			//fprintf(stderr,"KeySignature\n");
			skipBytes(rp,size);
			return 0;
		default:
			//fprintf(stderr,"OperationData\n");
			skipBytes(rp,size);
			return 0;
	}
}

midi.h

#ifndef MIDI_H_INCLUDED
#define MIDI_H_INCLUDED
#include<stdio.h>
#include<stdlib.h>
#define DRUM_CH 9
#define DRUM_NOTE 48
#define DEFAULT_OCTAVE 4


typedef struct _fileheader{
	char chk[4];//チェックサム(Mthd)
	int size;//SMFHeaderのサイズ
}FileHeader;

typedef struct _smfheader{
	short format;//フォーマット(0 or 1）
	short tracks;//トラック数
	short timebase;//分解能
}SmfHeader;

typedef struct _trackheader{
	char chk[4];//チェックサム(MTrk)
	int size;//トラックサイズ
}TrackHeader;

typedef struct _truckdata{
	char *data;
	int size;
}TruckData;

typedef struct _midifile{
	FileHeader *fh;
	SmfHeader *sh;
	TrackHeader *th;
	TruckData *td;
}Midi;

static char NOTENAME[][3]={"c","c+","d","d+","e","f","f+","g","g+","a","a+","b"};

void convEndian(char *c,int s);
Midi *newMidi();
void terminateMidi(Midi *m);
void loadMidi(Midi *m,char *filename);
void showMidi(Midi *m);
void showTrackData(Midi *m,int n);
int putNoteData(int *octave,int notenum,int span,int timebase);
int putRestData(int span,int timebase);
int getCommonData(char **rp,int count,int stat,int *octave,int timebase);
int getExclusiveData(char **rp,int count);
int getOperationData(char **rp,int count,int timebase);
int getConstantLengthParam(char **rp,int n);
int getVariableLengthParam(char **rp);
int getByte(char **rp);
void skipBytes(char **rp,int n);
void printString(char **rp,int n);
int gcd(int a,int b);
#endif