midifile.c

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                        }
                        metaevent(type);
                        break;

                case 0xf0:              /* start of system exclusive */

                        /* watch out - Don't combine the next 2 statements */
                        lng = readvarinum();
                        if (midifile_error) return;
                        lookfor = Mf_toberead - lng;
                        msginit();
                        msgadd(0xf0);

                        while ( Mf_toberead > lookfor ) {
                                c = egetc();
                                if (midifile_error) return;
                                msgadd(c);
                        }
                        if ( c==0xf7 || Mf_nomerge==0 )
                                sysex();
                        else
                                sysexcontinue = 1;  /* merge into next msg */
                        break;

                case 0xf7:      /* sysex continuation or arbitrary stuff */

                        /* watch out - Don't combine the next 2 statements */
                        lng = readvarinum();
                        if (midifile_error) return;
                        lookfor = Mf_toberead - lng;

                        if ( ! sysexcontinue )
                                msginit();

                        while ( Mf_toberead > lookfor ) {
                                c = egetc();
                                if (midifile_error) return;
                                msgadd(c);
                        }
                        if ( ! sysexcontinue ) {
                                if ( Mf_arbitrary )
                                        (*Mf_arbitrary)(msgleng(),msg());
                        }
                        else if ( c == 0xf7 ) {
                                sysex();
                                sysexcontinue = 0;
                        }
                        break;
                default:

                        badbyte(c);

                        break;
                }
        }
        if ( Mf_endtrack )
                (*Mf_endtrack)();
        return;
}

static void
badbyte(c)
int c;
{
        char buff[32];

        (void) sprintf(buff,"unexpected byte: 0x%02x",c);
        mferror(buff);
}

static void
metaevent(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)(to32bit(0,m[0],m[1],m[2]));
                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_sqspecific )
                        (*Mf_sqspecific)(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;

        switch ( status & 0xf0 ) {
        case NOTEOFF:
                if ( Mf_off )
                        (*Mf_off)(chan,c1,c2);
                break;
        case NOTEON:
                if ( Mf_on )
                        (*Mf_on)(chan,c1,c2);
                break;
        case PRESSURE:
                if ( Mf_pressure )
                        (*Mf_pressure)(chan,c1,c2);
                break;
        case CONTROLLER:
                if ( Mf_controller )
                        (*Mf_controller)(chan,c1,c2);
                break;
        case PITCHBEND:
                if ( Mf_pitchbend )
                        (*Mf_pitchbend)(chan,c1,c2);
                break;
        case PROGRAM:
                if ( Mf_program )
                        (*Mf_program)(chan,c1);
                break;
        case CHANPRESSURE:
                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();
        if (midifile_error) return 0;

        value = (long) c;
        if ( c & 0x80 ) {
                value &= 0x7f;
                do {
                        c = egetc();
                        if (midifile_error) return 0;
                        value = (value << 7) + (c & 0x7f);
                } while (c & 0x80);
        }
        return (value);
}

static long
to32bit(c1,c2,c3,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(); if (midifile_error) return 0;
        c2 = egetc(); if (midifile_error) return 0;
        c3 = egetc(); if (midifile_error) return 0;
        c4 = egetc(); if (midifile_error) return 0;
        return to32bit(c1,c2,c3,c4);
}

static int
read16bit()
{
        int c1, c2;
        c1 = egetc(); if (midifile_error) return 0;
        c2 = egetc(); if (midifile_error) return 0;
        return to16bit(c1,c2);
}

static void
mferror(s)
char *s;
{
        if ( Mf_error )
                (*Mf_error)(s);
        midifile_error = 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 = 0;       /* 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 )
                msgenlarge();
        Msgbuff[Msgindex++] = c;
}

static void
msgenlarge()
{
        char *newmess;
        char *oldmess = Msgbuff;
        int oldleng = Msgsize;

        Msgsize += MSGINCREMENT;
        newmess = MALLOC((sizeof(char)*Msgsize) );

        /* copy old message into larger new one */
        if ( oldmess != 0 ) {
                register char *p = newmess;
                register char *q = oldmess;
                register char *endq = &oldmess[oldleng];

                for ( ; q!=endq ; p++,q++ )
                        *p = *q;
                free(oldmess);
        }
        Msgbuff = newmess;
}