diff options
Diffstat (limited to 'alsa-lib/test/midifile.c')
| -rw-r--r-- | alsa-lib/test/midifile.c | 1173 |
1 files changed, 0 insertions, 1173 deletions
diff --git a/alsa-lib/test/midifile.c b/alsa-lib/test/midifile.c deleted file mode 100644 index 8d6ba90..0000000 --- a/alsa-lib/test/midifile.c +++ /dev/null @@ -1,1173 +0,0 @@ -/* - * midifile 1.11 - * - * Read and write a MIDI file. Externally-assigned function pointers are - * called upon recognizing things in the file. - * - * Original release ? - * June 1989 - Added writing capability, M. Czeiszperger. - * - * The file format implemented here is called - * Standard MIDI Files, and is part of the Musical - * instrument Digital Interface specification. - * The spec is available from: - * - * International MIDI Association - * 5316 West 57th Street - * Los Angeles, CA 90056 - * - * An in-depth description of the spec can also be found - * in the article "Introducing Standard MIDI Files", published - * in Electronic Musician magazine, April, 1989. - * - * February 1993 - Minor adjustments, Greg Lee: - * (1) can now set the global variable Mf_interactive to 1 to prevent the - * reading functions from looking for file and track headers - * (2) can now write system exclusive data with - * mf_write_midi_event(delta_time, system_exclusive, 0, data, size) - * (3) changed definition of 'sequencer_specific' in midifile.h to 0x7f - * (4) changed mf_write_tempo to take additional delta_time as first argument - * (since delta need not be zero) - * (5) added function mf_write_seqnum(unsigned long delta_time, unsigned seqnum) - * (6) changed mf_write_midi_event to use running status - * (7) removed the code to write an end of track meta event automatically - * -- this must now be done by the user of the library (I changed - * it because I need to be able to control the time delta of this - * meta event) - * (8) added global variables Mf_division, Mf_currtempo, Mf_realtime, which - * are updated by the reading functions. Mf_realtime is useful, - * because Mf_currtime does not really measure time at all, since - * its units change value at every tempo change. Mf_realtime is - * the midi-time elapsed in units of 1/16 of a centisecond (but it - * does not handle SMPTE times) - * (9) maintains a history of tempo settings to update Mf_currtempo, - * to handle tempo tracks. - * (10) if there is an Mf_error function, the error routine no longer - * exits, leaving it to the application to do this. - * (11) chanmessage skips over invalid c1 command bytes > 127 and - * adjusts invalid c2 argument byte > 127 to 127. - * (12) readmt returns EOF when it encounters a 0 or 0x1a byte instead of an expected - * header string (some midi files have padding at end). - */ -#define NO_LC_DEFINES -#include "midifile.h" -#ifdef NO_LC_DEFINES -#define system_exclusive 0xf0 -#define meta_event 0xFF -#define set_tempo 0x51 -#define lowerbyte(x) ((unsigned char)(x & 0xff)) -#define upperbyte(x) ((unsigned char)((x & 0xff00)>>8)) -#endif - -#define NULLFUNC 0 -#if 0 -#define NULL 0 -#endif - -#define THINK - -#ifdef THINK -#include <stdlib.h> -#endif - -#include <stdio.h> -#include <values.h> - -#include <string.h> -/*void exit(), free();*/ - -/* public stuff */ - -/* Functions to be called while processing the MIDI file. */ -int (*Mf_getc) () = NULLFUNC; -void (*Mf_error) () = NULLFUNC; -void (*Mf_header) () = NULLFUNC; -void (*Mf_trackstart) () = NULLFUNC; -void (*Mf_trackend) () = NULLFUNC; -void (*Mf_noteon) () = NULLFUNC; -void (*Mf_noteoff) () = NULLFUNC; -void (*Mf_pressure) () = NULLFUNC; -void (*Mf_parameter) () = NULLFUNC; -void (*Mf_pitchbend) () = NULLFUNC; -void (*Mf_program) () = NULLFUNC; -void (*Mf_chanpressure) () = NULLFUNC; -void (*Mf_sysex) () = NULLFUNC; -void (*Mf_arbitrary) () = NULLFUNC; -void (*Mf_metamisc) () = NULLFUNC; -void (*Mf_seqnum) () = NULLFUNC; -void (*Mf_eot) () = NULLFUNC; -void (*Mf_smpte) () = NULLFUNC; -void (*Mf_tempo) () = NULLFUNC; -void (*Mf_timesig) () = NULLFUNC; -void (*Mf_keysig) () = NULLFUNC; -void (*Mf_seqspecific) () = NULLFUNC; -void (*Mf_text) () = NULLFUNC; - -/* Functions to implement in order to write a MIDI file */ -int (*Mf_putc) () = NULLFUNC; -int (*Mf_writetrack) () = NULLFUNC; -int (*Mf_writetempotrack) () = NULLFUNC; - -int Mf_nomerge = 0; /* 1 => continue'ed system exclusives are */ - /* not collapsed. */ -int Mf_interactive = 0; /* 1 => file and track headers are not required */ -unsigned long Mf_currtime = 0L; /* current time in delta-time units */ -unsigned long Mf_realtime = 0L; /* current time in 1/16 centisecond-time units */ -static double Mf_f_realtime = 0;/* as above, floating */ -static double old_f_realtime = 0; -int Mf_division = 96; -unsigned long Mf_currtempo = 500000; -static unsigned long old_currtempo = 500000; -static unsigned long old_realtime = 0; -static unsigned long old_currtime = 0; -static unsigned long revised_time = 0; -static unsigned long tempo_change_time = 0; - -#define MAX_HISTORY 512 -static unsigned long tempo_history[MAX_HISTORY]; -static unsigned long tempo_history_time[MAX_HISTORY]; -static int tempo_history_count = 0; - -/* private stuff */ -static long Mf_toberead = 0L; -static long Mf_numbyteswritten = 0L; - -static long readvarinum (); -static long read32bit (); -static long to32bit (); -static int read16bit (); -static int to16bit (); -static char *msg (); -static void readheader (); -static int readtrack (); -static void badbyte (); -static void metaevent (); -static void sysex (); -static void chanmessage (); -static void msginit (); -static int msgleng (); -static void msgadd (); -static void biggermsg (); -static int eputc (unsigned char c); - -double mf_ticks2sec (unsigned long ticks, int division, unsigned long tempo); -int mf_write_meta_event (); -void mf_write_tempo (); -void mf_write_seqnum (); -void WriteVarLen (); - -#ifdef READ_MODS -#include "mp_mod.c" -static int mod_file_flag = 0; -#endif /* READ_MODS */ -static int force_exit; - -void -mfread () -{ - force_exit = 0; - if (Mf_getc == NULLFUNC) - mferror ("mfread() called without setting Mf_getc"); - - readheader (); -#ifdef READ_MODS - if (mod_file_flag) - do_module(); - else -#endif - while (readtrack () && !force_exit) - ; -} - -/* for backward compatibility with the original lib */ -void -midifile () -{ - mfread (); -} - -static -int -readmt (s) /* read through the "MThd" or "MTrk" header string */ - char *s; -{ - int n = 0; - char *p = s; - int c; - - while (n++ < 4 && (c = (*Mf_getc) ()) != EOF) - { - if (c != *p++) - { - char buff[32]; - if (!c) return(EOF); - if (c == 0x1a) return(EOF); - (void) strcpy (buff, "expecting "); - (void) strcat (buff, s); - mferror (buff); - break; - } - } - return (c); -} - -static -int -egetc () /* read a single character and abort on EOF */ -{ - int c = (*Mf_getc) (); - - if (c == EOF) { - mferror ("premature EOF"); - force_exit = 1; - } - Mf_toberead--; - return (c); -} - -static -void -readheader () /* read a header chunk */ -{ - int format, ntrks, division; - - - Mf_division = 96; - Mf_currtempo = 500000; - old_currtempo = 500000; - tempo_history_count = 0; - tempo_history[tempo_history_count] = Mf_currtempo; - tempo_history_time[tempo_history_count] = 0; - - if (Mf_interactive) - { - Mf_toberead = 0; - format = 0; - ntrks = 1; - division = 96; - } - else -#ifdef READ_MODS - if (!strncmp(Mf_file_contents, "MThd", 4)) -#endif - { - if (readmt ("MThd") == EOF) - return; - - Mf_toberead = read32bit (); - format = read16bit (); - ntrks = read16bit (); - Mf_division = division = read16bit (); - } -#ifdef READ_MODS - else - { - format = 0; - ntrks = 1; - division = Mf_division; - Mf_toberead = 0; - mod_file_flag = 1; - } -#endif - - if (Mf_header) - (*Mf_header) (format, ntrks, division); - - /* flush any extra stuff, in case the length of header is not 6 */ - while (Mf_toberead > 0 && !force_exit) - (void) egetc (); -} - - -/*#define DEBUG_TIMES*/ -static -unsigned long -find_tempo() -{ - int i; - unsigned long old_tempo = Mf_currtempo; - unsigned long new_tempo = Mf_currtempo; - - for (i = 0; i <= tempo_history_count; i++) { - if (tempo_history_time[i] <= Mf_currtime) old_tempo = tempo_history[i]; - new_tempo = tempo_history[i]; - if (tempo_history_time[i] > revised_time) break; - } - if (i > tempo_history_count || tempo_history_time[i] > Mf_currtime) { -#ifdef DEBUG_TIMES -printf("[past %d, old_tempo %d]\n", tempo_history_time[i], old_tempo); -#endif - revised_time = Mf_currtime; - return(old_tempo); - } - tempo_change_time = revised_time = tempo_history_time[i]; -#ifdef DEBUG_TIMES -printf("[revised_time %d, new_tempo %d]\n", revised_time, new_tempo); -#endif - return(new_tempo); -} - -static -int -readtrack () /* read a track chunk */ -{ - /* This array is indexed by the high half of a status byte. It's */ - /* value is either the number of bytes needed (1 or 2) for a channel */ - /* message, or 0 (meaning it's not a channel message). */ - static int chantype[] = - { - 0, 0, 0, 0, 0, 0, 0, 0, /* 0x00 through 0x70 */ - 2, 2, 2, 2, 1, 1, 2, 0 /* 0x80 through 0xf0 */ - }; - long lookfor; - int c, c1, type; - int sysexcontinue = 0; /* 1 if last message was an unfinished sysex */ - int running = 0; /* 1 when running status used */ - int status = 0; /* status value (e.g. 0x90==note-on) */ - int needed; - - if (Mf_interactive) - { - Mf_toberead = MAXINT; - } - else - { - if (readmt ("MTrk") == EOF) - return (0); - - Mf_toberead = read32bit (); - } - Mf_currtime = Mf_realtime = 0; - Mf_f_realtime = old_f_realtime = 0; - old_currtime = old_realtime = 0; - Mf_currtempo = find_tempo(); - - if (Mf_trackstart) - (*Mf_trackstart) (); - - while (!force_exit && (Mf_interactive || Mf_toberead > 0)) - { - - if (Mf_interactive) - Mf_currtime += 1; - else - { - double delta_secs; - unsigned long delta_ticks = readvarinum (); - revised_time = Mf_currtime; - Mf_currtime += delta_ticks; /* delta time */ - -/* - * Step through each tempo change from old_currtime up to now, - * revising Mf_realtime after each change. - */ - - while (revised_time < Mf_currtime) { - unsigned long save_time = revised_time; - unsigned long save_tempo = Mf_currtempo; - Mf_currtempo = find_tempo(); - - if (Mf_currtempo != old_currtempo) { - old_currtempo = Mf_currtempo; - old_realtime = Mf_realtime; - if (revised_time != tempo_change_time) { - old_f_realtime = Mf_f_realtime; - old_currtime = save_time; - } - delta_secs = mf_ticks2sec (revised_time-old_currtime, Mf_division, save_tempo); -#ifdef DEBUG_TIMES -printf("d(rev %d - old %d, div %d, tempo %d) = %.3f\n", -revised_time, old_currtime, Mf_division, save_tempo, delta_secs * 1600.0); -#endif - Mf_f_realtime = old_f_realtime + delta_secs * 1600.0; - Mf_realtime = (unsigned long)(0.5 + Mf_f_realtime); -#ifdef DEBUG_TIMES -printf("\tt=%d ticks ( = %d csec/16 < old %.2f + %.2f)\n", Mf_currtime, Mf_realtime, -old_f_realtime, delta_secs * 1600.0); -#endif - if (revised_time == tempo_change_time) { - old_currtime = revised_time; - old_f_realtime = Mf_f_realtime; - } - } - else { - delta_secs = mf_ticks2sec (revised_time-old_currtime, Mf_division, Mf_currtempo); -#ifdef DEBUG_TIMES -printf("d(rev %d - old %d, div %d, tempo %d) = %.3f\n", -revised_time, old_currtime, Mf_division, Mf_currtempo, delta_secs * 1600.0); -#endif - Mf_f_realtime = old_f_realtime + delta_secs * 1600.0; - Mf_realtime = (unsigned long)(0.5 + Mf_f_realtime); -#ifdef DEBUG_TIMES -printf("\tt=%d ticks ( = %d csec/16 < old %.2f + %.2f)\n", Mf_currtime, Mf_realtime, -old_f_realtime, delta_secs * 1600.0); -#endif - } - - - } - } - - c = egetc (); - - if (sysexcontinue && c != 0xf7) - mferror ("didn't find expected continuation of a sysex"); - - if ((c & 0x80) == 0) - { /* running status? */ - if (status == 0) - mferror ("unexpected running status"); - running = 1; - } - else - { - status = c; - running = 0; - } - - needed = chantype[(status >> 4) & 0xf]; - - if (needed) - { /* ie. is it a channel message? */ - - if (running) - c1 = c; - else - c1 = egetc (); - chanmessage (status, c1, (needed > 1) ? egetc () : 0); - continue;; - } - - switch (c) - { - - case 0xff: /* meta event */ - - type = egetc (); - lookfor = Mf_toberead - readvarinum (); - msginit (); - - while (Mf_toberead > lookfor) - msgadd (egetc ()); - - metaevent (type); - break; - - case 0xf0: /* start of system exclusive */ - - lookfor = Mf_toberead - readvarinum (); - msginit (); - msgadd (0xf0); - - while (Mf_toberead > lookfor) - msgadd (c = egetc ()); - - if (c == 0xf7 || Mf_nomerge == 0) - sysex (); - else - sysexcontinue = 1; /* merge into next msg */ - break; - - case 0xf7: /* sysex continuation or arbitrary stuff */ - - lookfor = Mf_toberead - readvarinum (); - - if (!sysexcontinue) - msginit (); - - while (Mf_toberead > lookfor) - msgadd (c = egetc ()); - - if (!sysexcontinue) - { - if (Mf_arbitrary) - (*Mf_arbitrary) (msgleng (), msg ()); - } - else if (c == 0xf7) - { - sysex (); - sysexcontinue = 0; - } - break; - default: - badbyte (c); - break; - } - } - if (Mf_trackend) - (*Mf_trackend) (); - return (1); -} - -static -void -badbyte (c) - int c; -{ - char buff[32]; - - (void) sprintf (buff, "unexpected byte: 0x%02x", c); - mferror (buff); -} - -static -void -metaevent (int type) -{ - int leng = msgleng (); - char *m = msg (); - - switch (type) - { - case 0x00: - if (Mf_seqnum) - (*Mf_seqnum) (to16bit (m[0], m[1])); - break; - case 0x01: /* Text event */ - case 0x02: /* Copyright notice */ - case 0x03: /* Sequence/Track name */ - case 0x04: /* Instrument name */ - case 0x05: /* Lyric */ - case 0x06: /* Marker */ - case 0x07: /* Cue point */ - case 0x08: - case 0x09: - case 0x0a: - case 0x0b: - case 0x0c: - case 0x0d: - case 0x0e: - case 0x0f: - /* These are all text events */ - if (Mf_text) - (*Mf_text) (type, leng, m); - break; - case 0x2f: /* End of Track */ - if (Mf_eot) - (*Mf_eot) (); - break; - case 0x51: /* Set tempo */ - if (Mf_tempo) - (*Mf_tempo) (Mf_currtempo = to32bit (0, m[0], m[1], m[2])); - if (tempo_history[tempo_history_count] == Mf_currtempo) break; - if (tempo_history_time[tempo_history_count] > Mf_currtime) break; - if (tempo_history_count < MAX_HISTORY - 1) tempo_history_count++; - tempo_history[tempo_history_count] = Mf_currtempo; - tempo_history_time[tempo_history_count] = Mf_currtime; - break; - case 0x54: - if (Mf_smpte) - (*Mf_smpte) (m[0], m[1], m[2], m[3], m[4]); - break; - case 0x58: - if (Mf_timesig) - (*Mf_timesig) (m[0], m[1], m[2], m[3]); - break; - case 0x59: - if (Mf_keysig) - (*Mf_keysig) (m[0], m[1]); - break; - case 0x7f: - if (Mf_seqspecific) - (*Mf_seqspecific) (leng, m); - break; - default: - if (Mf_metamisc) - (*Mf_metamisc) (type, leng, m); - } -} - -static -void -sysex () -{ - if (Mf_sysex) - (*Mf_sysex) (msgleng (), msg ()); -} - -static -void -chanmessage (status, c1, c2) - int status; - int c1, c2; -{ - int chan = status & 0xf; - - /* I found a midi file with Mod Wheel values 128. --gl */ - - if (c1 > 127) /*mferror("chanmessage: bad c1") ??*/ return; - if (c2 > 127) c2 = 127; - - switch (status & 0xf0) - { - case 0x80: - if (Mf_noteoff) - (*Mf_noteoff) (chan, c1, c2); - break; - case 0x90: - if (Mf_noteon) - (*Mf_noteon) (chan, c1, c2); - break; - case 0xa0: - if (Mf_pressure) - (*Mf_pressure) (chan, c1, c2); - break; - case 0xb0: - if (Mf_parameter) - (*Mf_parameter) (chan, c1, c2); - break; - case 0xe0: - if (Mf_pitchbend) - (*Mf_pitchbend) (chan, c1, c2); - break; - case 0xc0: - if (Mf_program) - (*Mf_program) (chan, c1); - break; - case 0xd0: - if (Mf_chanpressure) - (*Mf_chanpressure) (chan, c1); - break; - } -} - -/* readvarinum - read a varying-length number, and return the */ -/* number of characters it took. */ - -static long -readvarinum () -{ - long value; - int c; - - c = egetc (); - value = c; - if (c & 0x80) - { - value &= 0x7f; - do - { - c = egetc (); - value = (value << 7) + (c & 0x7f); - } - while (c & 0x80); - } - return (value); -} - -static long -to32bit (int c1, int c2, int c3, int c4) -{ - long value = 0L; - - value = (c1 & 0xff); - value = (value << 8) + (c2 & 0xff); - value = (value << 8) + (c3 & 0xff); - value = (value << 8) + (c4 & 0xff); - return (value); -} - -static int -to16bit (c1, c2) - int c1, c2; -{ - return ((c1 & 0xff) << 8) + (c2 & 0xff); -} - -static long -read32bit () -{ - int c1, c2, c3, c4; - - c1 = egetc (); - c2 = egetc (); - c3 = egetc (); - c4 = egetc (); - return to32bit (c1, c2, c3, c4); -} - -static int -read16bit () -{ - int c1, c2; - c1 = egetc (); - c2 = egetc (); - return to16bit (c1, c2); -} - -/* static */ -void -mferror (s) - char *s; -{ - if (Mf_error) - (*Mf_error) (s); - else exit (1); -} - -/* The code below allows collection of a system exclusive message of */ -/* arbitrary length. The Msgbuff is expanded as necessary. The only */ -/* visible data/routines are msginit(), msgadd(), msg(), msgleng(). */ - -#define MSGINCREMENT 128 -static char *Msgbuff = NULL; /* message buffer */ -static int Msgsize = 0; /* Size of currently allocated Msg */ -static int Msgindex = 0; /* index of next available location in Msg */ - -static -void -msginit () -{ - Msgindex = 0; -} - -static char * -msg () -{ - return (Msgbuff); -} - -static -int -msgleng () -{ - return (Msgindex); -} - -static -void -msgadd (c) - int c; -{ - /* If necessary, allocate larger message buffer. */ - if (Msgindex >= Msgsize) - biggermsg (); - Msgbuff[Msgindex++] = c; -} - -static -void -biggermsg () -{ -/* char *malloc(); */ - char *newmess; - char *oldmess = Msgbuff; - int oldleng = Msgsize; - - Msgsize += MSGINCREMENT; - newmess = (char *) malloc ((unsigned) (sizeof (char) * Msgsize)); - - if (newmess == NULL) - mferror ("malloc error!"); - - /* copy old message into larger new one */ - if (oldmess != NULL) - { - register char *p = newmess; - register char *q = oldmess; - register char *endq = &oldmess[oldleng]; - - for (; q != endq; p++, q++) - *p = *q; - free (oldmess); - } - Msgbuff = newmess; -} - -static int laststatus = 0; - -/* - * mfwrite() - The only function you'll need to call to write out - * a midi file. - * - * format 0 - Single multi-channel track - * 1 - Multiple simultaneous tracks - * 2 - One or more sequentially independent - * single track patterns - * ntracks The number of tracks in the file. - * division This is kind of tricky, it can represent two - * things, depending on whether it is positive or negative - * (bit 15 set or not). If bit 15 of division is zero, - * bits 14 through 0 represent the number of delta-time - * "ticks" which make up a quarter note. If bit 15 of - * division is a one, delta-times in a file correspond to - * subdivisions of a second similar to SMPTE and MIDI - * time code. In this format bits 14 through 8 contain - * one of four values - 24, -25, -29, or -30, - * corresponding to the four standard SMPTE and MIDI - * time code frame per second formats, where -29 - * represents 30 drop frame. The second byte - * consisting of bits 7 through 0 corresponds the the - * resolution within a frame. Refer the Standard MIDI - * Files 1.0 spec for more details. - * fp This should be the open file pointer to the file you - * want to write. It will have be a global in order - * to work with Mf_putc. - */ -void -mfwrite (format, ntracks, division, fp) - int format, ntracks, division; - FILE *fp; -{ - int i; - void mf_write_track_chunk (), mf_write_header_chunk (); - - if (Mf_putc == NULLFUNC) - mferror ("mfmf_write() called without setting Mf_putc"); - - if (Mf_writetrack == NULLFUNC) - mferror ("mfmf_write() called without setting Mf_mf_writetrack"); - - laststatus = 0; - - /* every MIDI file starts with a header */ - mf_write_header_chunk (format, ntracks, division); - - laststatus = 0; - - /* In format 1 files, the first track is a tempo map */ - if (format == 1 && (Mf_writetempotrack)) - { - (*Mf_writetempotrack) (); - } - - /* The rest of the file is a series of tracks */ - for (i = 0; i < ntracks; i++) - mf_write_track_chunk (i, fp); -} - -void -mf_write_track_chunk (which_track, fp) - int which_track; - FILE *fp; -{ - unsigned long trkhdr, trklength; - long offset, place_marker; - void write16bit (), write32bit (); - - - laststatus = 0; - - trkhdr = MTrk; - trklength = 0; - - /* Remember where the length was written, because we don't - know how long it will be until we've finished writing */ - offset = ftell (fp); - -#ifdef DEBUG - printf ("offset = %d\n", (int) offset); -#endif - - /* Write the track chunk header */ - write32bit (trkhdr); - write32bit (trklength); - - Mf_numbyteswritten = 0L; /* the header's length doesn't count */ - - if (Mf_writetrack) - { - (*Mf_writetrack) (which_track); - } - - /* mf_write End of track meta event */ -/* but this does not necessarily have a delta of 0, so - * I don't want to do it -- leave it up to the user of the - * library functions to do - * --gl - eputc(0); - eputc(laststatus = meta_event); - eputc(end_of_track); - - eputc(0); - */ - - /* It's impossible to know how long the track chunk will be beforehand, - so the position of the track length data is kept so that it can - be written after the chunk has been generated */ - place_marker = ftell (fp); - - /* This method turned out not to be portable because the - parameter returned from ftell is not guaranteed to be - in bytes on every machine */ - /* track.length = place_marker - offset - (long) sizeof(track); */ - -#ifdef DEBUG - printf ("length = %d\n", (int) trklength); -#endif - - if (fseek (fp, offset, 0) < 0) - mferror ("error seeking during final stage of write"); - - trklength = Mf_numbyteswritten; - - /* Re-mf_write the track chunk header with right length */ - write32bit (trkhdr); - write32bit (trklength); - - fseek (fp, place_marker, 0); -} /* End gen_track_chunk() */ - - -void -mf_write_header_chunk (format, ntracks, division) - int format, ntracks, division; -{ - unsigned long ident, length; - void write16bit (), write32bit (); - - ident = MThd; /* Head chunk identifier */ - length = 6; /* Chunk length */ - - /* individual bytes of the header must be written separately - to preserve byte order across cpu types :-( */ - write32bit (ident); - write32bit (length); - write16bit (format); - write16bit (ntracks); - write16bit (division); -} /* end gen_header_chunk() */ - - -/* - * mf_write_midi_event() - * - * Library routine to mf_write a single MIDI track event in the standard MIDI - * file format. The format is: - * - * <delta-time><event> - * - * In this case, event can be any multi-byte midi message, such as - * "note on", "note off", etc. - * - * delta_time - the time in ticks since the last event. - * type - the type of meta event. - * chan - The midi channel. - * data - A pointer to a block of chars containing the META EVENT, - * data. - * size - The length of the meta-event data. - */ -int -mf_write_midi_event (delta_time, type, chan, data, size) - unsigned long delta_time; - int chan, type; - unsigned long size; - char *data; -{ - int i; - unsigned char c; - - WriteVarLen (delta_time); - - /* all MIDI events start with the type in the first four bits, - and the channel in the lower four bits */ - if (type == system_exclusive || type == 0xf7) - { - c = type; - laststatus = 0; - } - else - c = type | chan; - - if (chan > 15) - perror ("error: MIDI channel greater than 16\n"); - - if (laststatus != c) - eputc (laststatus = c); - - if (type == system_exclusive || type == 0xf7) - WriteVarLen (size); - - /* write out the data bytes */ - for (i = 0; i < (int)size; i++) - eputc (data[i]); - - return (size); -} /* end mf_write MIDI event */ - -/* - * mf_write_meta_event() - * - * Library routine to mf_write a single meta event in the standard MIDI - * file format. The format of a meta event is: - * - * <delta-time><FF><type><length><bytes> - * - * delta_time - the time in ticks since the last event. - * type - the type of meta event. - * data - A pointer to a block of chars containing the META EVENT, - * data. - * size - The length of the meta-event data. - */ -int -mf_write_meta_event (delta_time, type, data, size) - unsigned long delta_time; - unsigned char *data, type; - unsigned long size; -{ - int i; - - WriteVarLen (delta_time); - - /* This marks the fact we're writing a meta-event */ - eputc (laststatus = meta_event); - - /* The type of meta event */ - eputc (type); - - /* The length of the data bytes to follow */ - WriteVarLen (size); - - for (i = 0; i < (int)size; i++) - { - if (eputc (data[i]) != data[i]) - return (-1); - } - return (size); -} /* end mf_write_meta_event */ - -void -mf_write_tempo (delta_time, tempo) - unsigned long delta_time; - unsigned long tempo; -{ - /* Write tempo */ - /* all tempos are written as 120 beats/minute, */ - /* expressed in microseconds/quarter note */ - - WriteVarLen (delta_time); - eputc (laststatus = meta_event); - eputc (set_tempo); - - eputc (3); - eputc ((unsigned) (0xff & (tempo >> 16))); - eputc ((unsigned) (0xff & (tempo >> 8))); - eputc ((unsigned) (0xff & tempo)); -} - -void -mf_write_seqnum (delta_time, seqnum) - unsigned long delta_time; - unsigned seqnum; -{ - - WriteVarLen (delta_time); - eputc (laststatus = meta_event); - eputc (0); - - eputc ((unsigned) (0xff & (seqnum >> 8))); - eputc ((unsigned) (0xff & seqnum)); -} - -unsigned long -mf_sec2ticks (secs, division, tempo) - int division; - unsigned long tempo; - double secs; -{ - return (unsigned long) (((secs * 1000.0) / 4.0 * division) / tempo); -} - -/* - * Write multi-length bytes to MIDI format files - */ -void -WriteVarLen (value) - unsigned long value; -{ - unsigned long buffer; - - buffer = value & 0x7f; - while ((value >>= 7) > 0) - { - buffer <<= 8; - buffer |= 0x80; - buffer += (value & 0x7f); - } - while (1) - { - eputc ((unsigned) (buffer & 0xff)); - - if (buffer & 0x80) - buffer >>= 8; - else - return; - } -} /* end of WriteVarLen */ - -/* - * This routine converts delta times in ticks into seconds. The - * else statement is needed because the formula is different for tracks - * based on notes and tracks based on SMPTE times. - * - */ -double -mf_ticks2sec (ticks, division, tempo) - int division; - unsigned long tempo; - unsigned long ticks; -{ - double smpte_format, smpte_resolution; - - if (division > 0) - return ((double) (((double) (ticks) * (double) (tempo)) / ((double) (division) * 1000000.0))); - else - { - smpte_format = upperbyte (division); - smpte_resolution = lowerbyte (division); - return (double) ((double) ticks / (smpte_format * smpte_resolution * 1000000.0)); - } -} /* end of ticks2sec() */ - - -/* - * write32bit() - * write16bit() - * - * These routines are used to make sure that the byte order of - * the various data types remains constant between machines. This - * helps make sure that the code will be portable from one system - * to the next. It is slightly dangerous that it assumes that longs - * have at least 32 bits and ints have at least 16 bits, but this - * has been true at least on PCs, UNIX machines, and Macintosh's. - * - */ -void -write32bit (data) - unsigned long data; -{ - eputc ((unsigned) ((data >> 24) & 0xff)); - eputc ((unsigned) ((data >> 16) & 0xff)); - eputc ((unsigned) ((data >> 8) & 0xff)); - eputc ((unsigned) (data & 0xff)); -} - -void -write16bit (data) - int data; -{ - eputc ((unsigned) ((data & 0xff00) >> 8)); - eputc ((unsigned) (data & 0xff)); -} - -/* write a single character and abort on error */ -static int -eputc (c) - unsigned char c; -{ - int return_val; - - if ((Mf_putc) == NULLFUNC) - { - mferror ("Mf_putc undefined"); - return (-1); - } - - return_val = (*Mf_putc) (c); - - if (return_val == EOF) - mferror ("error writing"); - - Mf_numbyteswritten++; - return (return_val); -} |