1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/.hgignore	Thu Jan 26 00:31:39 2012 +0200
     1.3 @@ -0,0 +1,4 @@
     1.4 +\.o$
     1.5 +\.d$
     1.6 +\.swp$
     1.7 +^test$

     2.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     2.2 +++ b/Makefile	Thu Jan 26 00:31:39 2012 +0200
     2.3 @@ -0,0 +1,18 @@
     2.4 +src = $(wildcard src/*.c) test.c
     2.5 +obj = $(src:.c=.o)
     2.6 +dep = $(obj:.o=.d)
     2.7 +bin = test
     2.8 +
     2.9 +CFLAGS = -pedantic -Wall -g -Isrc
    2.10 +
    2.11 +$(bin): $(obj)
    2.12 +	$(CC) -o $@ $(obj) $(LDFLAGS)
    2.13 +
    2.14 +-include $(dep)
    2.15 +
    2.16 +%.d: %.c
    2.17 +	@$(CPP) $(CFLAGS) $< -MM -MT $(@:.d=.o) >$@
    2.18 +
    2.19 +.PHONY: clean
    2.20 +clean:
    2.21 +	rm -f $(obj) $(bin)

     3.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     3.2 +++ b/src/midi.c	Thu Jan 26 00:31:39 2012 +0200
     3.3 @@ -0,0 +1,362 @@
     3.4 +#include <stdio.h>
     3.5 +#include <stdlib.h>
     3.6 +#include <string.h>
     3.7 +#include <errno.h>
     3.8 +#include <inttypes.h>
     3.9 +#include <unistd.h>
    3.10 +#include <fcntl.h>
    3.11 +#include <sys/mman.h>
    3.12 +#include <sys/stat.h>
    3.13 +#include <arpa/inet.h>
    3.14 +#include "midi.h"
    3.15 +
    3.16 +#define FMT_SINGLE		0
    3.17 +#define FMT_MULTI_TRACK	1
    3.18 +#define FMT_MULTI_SEQ	2
    3.19 +
    3.20 +/* meta events */
    3.21 +#define META_SEQ		0
    3.22 +#define META_TEXT		1
    3.23 +#define META_COPYRIGHT	2
    3.24 +#define META_NAME		3
    3.25 +#define META_INSTR		4
    3.26 +#define META_LYRICS		5
    3.27 +#define META_MARKER		6
    3.28 +#define META_CUE		7
    3.29 +#define META_CHANPREFIX	32
    3.30 +#define META_END_TRACK	47
    3.31 +#define META_TEMPO		81
    3.32 +#define META_SMPTE_OFFS	84
    3.33 +#define META_TMSIG		88
    3.34 +#define META_KEYSIG		89
    3.35 +#define META_SPECIFIC	127
    3.36 +
    3.37 +struct midi {
    3.38 +	int bpm;
    3.39 +
    3.40 +	int num_tracks;
    3.41 +	struct midi_track *tracks;
    3.42 +};
    3.43 +
    3.44 +struct midi_track {
    3.45 +	char *name;
    3.46 +	struct midi_event *head, *tail;
    3.47 +	int num_ev;
    3.48 +};
    3.49 +
    3.50 +struct midi_event {
    3.51 +	long dt;
    3.52 +	int type;
    3.53 +	int channel;
    3.54 +	int arg[2];
    3.55 +
    3.56 +	struct midi_event *next;
    3.57 +};
    3.58 +
    3.59 +#define CHUNK_HDR_SIZE	8
    3.60 +struct chunk_hdr {
    3.61 +	char id[4];
    3.62 +	uint32_t size;
    3.63 +	unsigned char data[1];
    3.64 +};
    3.65 +
    3.66 +struct midi_hdr {
    3.67 +	uint16_t fmt;	/* 0: single, 1: multi-track, 2: multiple independent */
    3.68 +	uint16_t num_tracks;
    3.69 +	uint16_t tm_div;
    3.70 +
    3.71 +} __attribute__ ((packed));
    3.72 +
    3.73 +static void destroy_track(struct midi_track *trk);
    3.74 +static int read_track(struct midi *midi, struct chunk_hdr *chunk);
    3.75 +static long read_vardata(unsigned char **pptr);
    3.76 +static int read_meta_event(struct midi *midi, struct midi_track *trk, unsigned char **pptr);
    3.77 +static int read_sysex_event(struct midi *midi, unsigned char **pptr);
    3.78 +static int ischunk(struct chunk_hdr *chunk, const char *name);
    3.79 +static struct chunk_hdr *mkchunk(void *ptr);
    3.80 +static struct chunk_hdr *skip_chunk(struct chunk_hdr *chunk);
    3.81 +static struct midi_hdr *mkmidi(void *ptr);
    3.82 +static void bigend(void *ptr, int sz);
    3.83 +static void *map_file(const char *fname, int *size);
    3.84 +static void unmap_file(void *mem, int size);
    3.85 +
    3.86 +#define IS_VALID_EVTYPE(x) ((x) >= MIDI_NOTE_OFF && (x) <= MIDI_PITCH_BEND)
    3.87 +
    3.88 +/* XXX the event arity table must match the MIDI_* defines in midi.h */
    3.89 +static int ev_arity[] = {
    3.90 +	0, 0, 0, 0, 0, 0, 0, 0,
    3.91 +	2, /* note off (note, velocity)*/
    3.92 +	2, /* note on (note, velocity)*/
    3.93 +	2, /* note aftertouch (note, aftertouch value) */
    3.94 +	2, /* controller (controller number, value) */
    3.95 +	1, /* prog change (prog number) */
    3.96 +	1, /* channel aftertouch (aftertouch value) */
    3.97 +	2  /* pitch bend (pitch LSB, pitch MSB) */
    3.98 +};
    3.99 +
   3.100 +
   3.101 +struct midi *load_midi(const char *fname)
   3.102 +{
   3.103 +	struct midi *midi;
   3.104 +	char *mem;
   3.105 +	int size;
   3.106 +	struct chunk_hdr *chunk;
   3.107 +	struct midi_hdr *hdr;
   3.108 +
   3.109 +	if(!(mem = map_file(fname, &size))) {
   3.110 +		return 0;
   3.111 +	}
   3.112 +	chunk = mkchunk(mem);
   3.113 +
   3.114 +	if(!ischunk(chunk, "MThd") || chunk->size != 6) {
   3.115 +		fprintf(stderr, "invalid or corrupted midi file: %s\n", fname);
   3.116 +		goto end;
   3.117 +	}
   3.118 +	hdr = mkmidi(chunk->data);
   3.119 +
   3.120 +	printf("format: %d\n", (int)hdr->fmt);
   3.121 +	printf("tracks: %d\n", (int)hdr->num_tracks);
   3.122 +
   3.123 +	if((hdr->tm_div & 0x8000) == 0) {
   3.124 +		/* division is in pulses / quarter note */
   3.125 +		printf("time division: %d ppqn\n", (int)hdr->tm_div);
   3.126 +	} else {
   3.127 +		/* division in frames / sec */
   3.128 +		int fps = (hdr->tm_div & 0x7f00) >> 8;
   3.129 +		int ticks_per_frame = hdr->tm_div & 0xff;
   3.130 +		printf("time division: %d fps, %d ticks/frame\n", fps, ticks_per_frame);
   3.131 +	}
   3.132 +
   3.133 +	if(!(midi = malloc(sizeof *midi))) {
   3.134 +		perror("failed to allocate memory");
   3.135 +		goto end;
   3.136 +	}
   3.137 +	if(!(midi->tracks = malloc(hdr->num_tracks * sizeof *midi->tracks))) {
   3.138 +		perror("failed to allocate memory");
   3.139 +		goto end;
   3.140 +	}
   3.141 +	midi->num_tracks = 0;
   3.142 +
   3.143 +	while((chunk = skip_chunk(chunk))) {
   3.144 +		if(ischunk(chunk, "MTrk")) {
   3.145 +			if(read_track(midi, chunk) == -1) {
   3.146 +				fprintf(stderr, "failed to read track\n");
   3.147 +			}
   3.148 +		} else {
   3.149 +			printf("ignoring chunk: %c%c%c%c\n", chunk->id[0], chunk->id[1], chunk->id[2], chunk->id[3]);
   3.150 +		}
   3.151 +	}
   3.152 +
   3.153 +end:
   3.154 +	unmap_file(mem, size);
   3.155 +	if(midi) {
   3.156 +		free_midi(midi);
   3.157 +		midi = 0;
   3.158 +	}
   3.159 +	return midi;
   3.160 +}
   3.161 +
   3.162 +void free_midi(struct midi *midi)
   3.163 +{
   3.164 +	int i;
   3.165 +
   3.166 +	if(!midi) return;
   3.167 +
   3.168 +	for(i=0; i<midi->num_tracks; i++) {
   3.169 +		destroy_track(midi->tracks + i);
   3.170 +	}
   3.171 +
   3.172 +	free(midi->tracks);	/* TODO free tracks properly */
   3.173 +	free(midi);
   3.174 +}
   3.175 +
   3.176 +static void destroy_track(struct midi_track *trk)
   3.177 +{
   3.178 +	free(trk->name);
   3.179 +	while(trk->head) {
   3.180 +		void *tmp = trk->head;
   3.181 +		trk->head = trk->head->next;
   3.182 +		free(tmp);
   3.183 +	}
   3.184 +}
   3.185 +
   3.186 +static int read_track(struct midi *midi, struct chunk_hdr *chunk)
   3.187 +{
   3.188 +	unsigned char *ptr;
   3.189 +	struct midi_track trk = {0, 0, 0, 0};
   3.190 +
   3.191 +	if(!ischunk(chunk, "MTrk")) {
   3.192 +		return -1;
   3.193 +	}
   3.194 +
   3.195 +	ptr = chunk->data;
   3.196 +	while(ptr < chunk->data + chunk->size) {
   3.197 +		long dt;
   3.198 +		unsigned char stat;
   3.199 +
   3.200 +		/* TODO also convert dt to some standard unit */
   3.201 +		dt = read_vardata(&ptr);
   3.202 +		stat = *ptr++;
   3.203 +
   3.204 +		if(stat == 0xff) {
   3.205 +			read_meta_event(midi, &trk, &ptr);
   3.206 +		} else if(stat == 0xf0) {
   3.207 +			read_sysex_event(midi, &ptr);
   3.208 +		} else {
   3.209 +			struct midi_event *ev = malloc(sizeof *ev);
   3.210 +
   3.211 +			if(trk.head) {
   3.212 +				trk.tail->next = ev;
   3.213 +			} else {
   3.214 +				trk.head = ev;
   3.215 +			}
   3.216 +			trk.tail = ev;
   3.217 +			ev->next = 0;
   3.218 +			trk.num_ev++;
   3.219 +
   3.220 +			ev->dt = dt;
   3.221 +			ev->type = (stat >> 4) & 0xf;
   3.222 +			if(!IS_VALID_EVTYPE(ev->type)) {
   3.223 +				fprintf(stderr, "warning, skipping track with unknown event %d\n", ev->type);
   3.224 +				return -1;
   3.225 +			}
   3.226 +			ev->channel = stat & 0xf;
   3.227 +
   3.228 +			ev->arg[0] = *ptr++;
   3.229 +			if(ev_arity[ev->type] > 1) {
   3.230 +				ev->arg[1] = *ptr++;
   3.231 +			}
   3.232 +		}
   3.233 +	}
   3.234 +
   3.235 +	/* if we did actually add any events ... */
   3.236 +	if(trk.num_ev) {
   3.237 +		midi->tracks[midi->num_tracks++] = trk;
   3.238 +	}
   3.239 +	return 0;
   3.240 +}
   3.241 +
   3.242 +static long read_vardata(unsigned char **pptr)
   3.243 +{
   3.244 +	int i;
   3.245 +	long res = 0;
   3.246 +	unsigned char *ptr = *pptr;
   3.247 +
   3.248 +	for(i=0; i<4; i++) {
   3.249 +		res |= (long)(*ptr & 0x7f) << (i * 8);
   3.250 +
   3.251 +		/* if first bit is not set we're done */
   3.252 +		if((*ptr++ & 0x80) == 0)
   3.253 +			break;
   3.254 +	}
   3.255 +	*pptr = ptr;
   3.256 +	return res;
   3.257 +}
   3.258 +
   3.259 +static int read_meta_event(struct midi *midi, struct midi_track *trk, unsigned char **pptr)
   3.260 +{
   3.261 +	unsigned char *ptr = *pptr;
   3.262 +	unsigned char type;
   3.263 +	long size;
   3.264 +
   3.265 +	type = *ptr++;
   3.266 +	size = read_vardata(&ptr);
   3.267 +
   3.268 +	switch(type) {
   3.269 +	case META_NAME:
   3.270 +		free(trk->name);
   3.271 +		trk->name = malloc(size + 1);
   3.272 +		memcpy(trk->name, ptr, size);
   3.273 +		trk->name[size] = 0;
   3.274 +		break;
   3.275 +
   3.276 +	case META_TEMPO:
   3.277 +		/* TODO add a tempo change event to the midi struct */
   3.278 +		break;
   3.279 +
   3.280 +	default:
   3.281 +		break;
   3.282 +	}
   3.283 +	*pptr = ptr + size;
   3.284 +	return 0;
   3.285 +}
   3.286 +
   3.287 +/* ignore sysex events */
   3.288 +static int read_sysex_event(struct midi *midi, unsigned char **pptr)
   3.289 +{
   3.290 +	long size = read_vardata(pptr);
   3.291 +	*pptr += size;
   3.292 +	return 0;
   3.293 +}
   3.294 +
   3.295 +static int ischunk(struct chunk_hdr *chunk, const char *name)
   3.296 +{
   3.297 +	return memcmp(chunk->id, name, 4) == 0;
   3.298 +}
   3.299 +
   3.300 +static struct chunk_hdr *mkchunk(void *ptr)
   3.301 +{
   3.302 +	struct chunk_hdr *chdr = ptr;
   3.303 +	bigend(&chdr->size, sizeof chdr->size);
   3.304 +	return chdr;
   3.305 +}
   3.306 +
   3.307 +static struct chunk_hdr *skip_chunk(struct chunk_hdr *chunk)
   3.308 +{
   3.309 +	return mkchunk((char*)chunk + CHUNK_HDR_SIZE + chunk->size);
   3.310 +}
   3.311 +
   3.312 +static struct midi_hdr *mkmidi(void *ptr)
   3.313 +{
   3.314 +	struct midi_hdr *midi = ptr;
   3.315 +
   3.316 +	bigend(&midi->fmt, sizeof midi->fmt);
   3.317 +	bigend(&midi->num_tracks, sizeof midi->num_tracks);
   3.318 +	bigend(&midi->tm_div, sizeof midi->tm_div);
   3.319 +	return midi;
   3.320 +}
   3.321 +
   3.322 +static void bigend(void *ptr, int sz)
   3.323 +{
   3.324 +	switch(sz) {
   3.325 +	case 4:
   3.326 +		*((uint32_t*)ptr) = ntohl(*(uint32_t*)ptr);
   3.327 +		break;
   3.328 +
   3.329 +	case 2:
   3.330 +		*(uint16_t*)ptr = ntohs(*(uint16_t*)ptr);
   3.331 +		break;
   3.332 +
   3.333 +	case 1:
   3.334 +	default:
   3.335 +		break;
   3.336 +	}
   3.337 +}
   3.338 +
   3.339 +static void *map_file(const char *fname, int *size)
   3.340 +{
   3.341 +	int fd;
   3.342 +	struct stat st;
   3.343 +	void *mem;
   3.344 +
   3.345 +	if((fd = open(fname, O_RDONLY)) == -1) {
   3.346 +		fprintf(stderr, "failed to open midi file: %s: %s\n", fname, strerror(errno));
   3.347 +		return 0;
   3.348 +	}
   3.349 +	fstat(fd, &st);
   3.350 +
   3.351 +	if((mem = mmap(0, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0)) == (void*)-1) {
   3.352 +		fprintf(stderr, "failed to map midi file: %s: %s\n", fname, strerror(errno));
   3.353 +		close(fd);
   3.354 +		return 0;
   3.355 +	}
   3.356 +	close(fd);
   3.357 +
   3.358 +	*size = st.st_size;
   3.359 +	return mem;
   3.360 +}
   3.361 +
   3.362 +static void unmap_file(void *mem, int size)
   3.363 +{
   3.364 +	munmap(mem, size);
   3.365 +}

     4.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     4.2 +++ b/src/midi.h	Thu Jan 26 00:31:39 2012 +0200
     4.3 @@ -0,0 +1,29 @@
     4.4 +#ifndef MIDI_H_
     4.5 +#define MIDI_H_
     4.6 +
     4.7 +#include <stdio.h>
     4.8 +
     4.9 +struct midi;
    4.10 +struct midi_track;
    4.11 +struct midi_event;
    4.12 +
    4.13 +#define MIDI_NOTE_OFF			8
    4.14 +#define MIDI_NOTE_ON			9
    4.15 +#define MIDI_NOTE_AFTERTOUCH	10
    4.16 +#define MIDI_CONTROLLER			11
    4.17 +#define MIDI_PROG_CHANGE		12
    4.18 +#define MIDI_CHAN_AFTERTOUCH	13
    4.19 +#define MIDI_PITCH_BEND			14
    4.20 +
    4.21 +#ifdef __cplusplus
    4.22 +extern "C" {
    4.23 +#endif
    4.24 +
    4.25 +struct midi *load_midi(const char *fname);
    4.26 +void free_midi(struct midi *midi);
    4.27 +
    4.28 +#ifdef __cplusplus
    4.29 +}
    4.30 +#endif
    4.31 +
    4.32 +#endif	/* MIDI_H_ */

     5.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     5.2 +++ b/test.c	Thu Jan 26 00:31:39 2012 +0200
     5.3 @@ -0,0 +1,19 @@
     5.4 +#include <stdio.h>
     5.5 +#include "midi.h"
     5.6 +
     5.7 +int main(int argc, char **argv)
     5.8 +{
     5.9 +	struct midi *midi;
    5.10 +
    5.11 +	if(!argv[1]) {
    5.12 +		fprintf(stderr, "pass the path to a midi file\n");
    5.13 +		return 1;
    5.14 +	}
    5.15 +
    5.16 +	if(!(midi = load_midi(argv[1]))) {
    5.17 +		return 1;
    5.18 +	}
    5.19 +
    5.20 +	free_midi(midi);
    5.21 +	return 0;
    5.22 +}