/*
TiMidity -- Experimental MIDI to WAVE converter
Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>
This program is free software; you can redistribute it and/or modify
it under the terms of the Perl Artistic License, available in COPYING.
*/
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "SDL.h"
#include "options.h"
#include "timidity.h"
#include "common.h"
#include "instrum.h"
#include "playmidi.h"
/* Computes how many (fractional) samples one MIDI delta-time unit contains */
static void compute_sample_increment(MidiSong *song, Sint32 tempo,
Sint32 divisions)
{
double a;
a = (double) (tempo) * (double) (song->rate) * (65536.0/1000000.0) /
(double)(divisions);
song->sample_correction = (Sint32)(a) & 0xFFFF;
song->sample_increment = (Sint32)(a) >> 16;
SNDDBG(("Samples per delta-t: %d (correction %d)",
song->sample_increment, song->sample_correction));
}
/* Read variable-length number (7 bits per byte, MSB first) */
static Sint32 getvl(SDL_RWops *rw)
{
Sint32 l=0;
Uint8 c;
for (;;)
{
if (!SDL_RWread(rw, &c, 1, 1)) return l;
l += (c & 0x7f);
if (!(c & 0x80)) return l;
l<<=7;
}
}
/* Print a string from the file, followed by a newline. Any non-ASCII
or unprintable characters will be converted to periods. */
static int dumpstring(SDL_RWops *rw, Sint32 len, char *label)
{
signed char *s=safe_malloc(len+1);
if (len != (Sint32) SDL_RWread(rw, s, 1, len))
{
free(s);
return -1;
}
s[len]='\0';
while (len--)
{
if (s[len]<32)
s[len]='.';
}
SNDDBG(("%s%s", label, s));
free(s);
return 0;
}
#define MIDIEVENT(at,t,ch,pa,pb) \
new=safe_malloc(sizeof(MidiEventList)); \
new->event.time=at; new->event.type=t; new->event.channel=ch; \
new->event.a=pa; new->event.b=pb; new->next=0;\
return new;
#define MAGIC_EOT ((MidiEventList *)(-1))
/* Read a MIDI event, returning a freshly allocated element that can
be linked to the event list */
static MidiEventList *read_midi_event(MidiSong *song)
{
static Uint8 laststatus, lastchan;
static Uint8 nrpn=0, rpn_msb[16], rpn_lsb[16]; /* one per channel */
Uint8 me, type, a,b,c;
Sint32 len;
MidiEventList *new;
for (;;)
{
song->at += getvl(song->rw);
if (SDL_RWread(song->rw, &me, 1, 1) != 1)
{
SNDDBG(("read_midi_event: SDL_RWread() failure\n"));
return NULL;
}
if(me==0xF0 || me == 0xF7) /* SysEx event */
{
len=getvl(song->rw);
SDL_RWseek(song->rw, len, RW_SEEK_CUR);
}
else if(me==0xFF) /* Meta event */
{
SDL_RWread(song->rw, &type, 1, 1);
len=getvl(song->rw);
if (type>0 && type<16)
{
static char *label[]={
"Text event: ", "Text: ", "Copyright: ", "Track name: ",
"Instrument: ", "Lyric: ", "Marker: ", "Cue point: "};
dumpstring(song->rw, len, label[(type>7) ? 0 : type]);
}
else
switch(type)
{
case 0x2F: /* End of Track */
return MAGIC_EOT;
case 0x51: /* Tempo */
SDL_RWread(song->rw, &a, 1, 1);
SDL_RWread(song->rw, &b, 1, 1);
SDL_RWread(song->rw, &c, 1, 1);
MIDIEVENT(song->at, ME_TEMPO, c, a, b);
default:
SNDDBG(("(Meta event type 0x%02x, length %d)\n", type, len));
SDL_RWseek(song->rw, len, RW_SEEK_CUR);
break;
}
}
else
{
a=me;
if (a & 0x80) /* status byte */
{
lastchan=a & 0x0F;
laststatus=(a>>4) & 0x07;
SDL_RWread(song->rw, &a, 1, 1);
a &= 0x7F;
}
switch(laststatus)
{
case 0: /* Note off */
SDL_RWread(song->rw, &b, 1, 1);
b &= 0x7F;
MIDIEVENT(song->at, ME_NOTEOFF, lastchan, a,b);
case 1: /* Note on */
SDL_RWread(song->rw, &b, 1, 1);
b &= 0x7F;
MIDIEVENT(song->at, ME_NOTEON, lastchan, a,b);
case 2: /* Key Pressure */
SDL_RWread(song->rw, &b, 1, 1);
b &= 0x7F;
MIDIEVENT(song->at, ME_KEYPRESSURE, lastchan, a, b);
case 3: /* Control change */
SDL_RWread(song->rw, &b, 1, 1);
b &= 0x7F;
{
int control=255;
switch(a)
{
case 7: control=ME_MAINVOLUME; break;
case 10: control=ME_PAN; break;
case 11: control=ME_EXPRESSION; break;
case 64: control=ME_SUSTAIN; b = (b >= 64); break;
case 120: control=ME_ALL_SOUNDS_OFF; break;
case 121: control=ME_RESET_CONTROLLERS; break;
case 123: control=ME_ALL_NOTES_OFF; break;
/* These should be the SCC-1 tone bank switch
commands. I don't know why there are two, or
why the latter only allows switching to bank 0.
Also, some MIDI files use 0 as some sort of
continuous controller. This will cause lots of
warnings about undefined tone banks. */
case 0: control=ME_TONE_BANK; break;
case 32:
if (b!=0) {
SNDDBG(("(Strange: tone bank change 0x%02x)\n", b));
}
#if 0 /* `Bank Select LSB' is not worked at GS. Please ignore it. */
else
control=ME_TONE_BANK;
#endif
break;
case 100: nrpn=0; rpn_msb[lastchan]=b; break;
case 101: nrpn=0; rpn_lsb[lastchan]=b; break;
case 99: nrpn=1; rpn_msb[lastchan]=b; break;
case 98: nrpn=1; rpn_lsb[lastchan]=b; break;
case 6:
if (nrpn)
{
SNDDBG(("(Data entry (MSB) for NRPN %02x,%02x: %d)\n",
rpn_msb[lastchan], rpn_lsb[lastchan], b));
break;
}
switch((rpn_msb[lastchan]<<8) | rpn_lsb[lastchan])
{
case 0x0000: /* Pitch bend sensitivity */
control=ME_PITCH_SENS;
break;
case 0x7F7F: /* RPN reset */
/* reset pitch bend sensitivity to 2 */
MIDIEVENT(song->at, ME_PITCH_SENS, lastchan, 2, 0);
default:
SNDDBG(("(Data entry (MSB) for RPN %02x,%02x: %d)\n",
rpn_msb[lastchan], rpn_lsb[lastchan], b));
break;
}
break;
default:
SNDDBG(("(Control %d: %d)\n", a, b));
break;
}
if (control != 255)
{
MIDIEVENT(song->at, control, lastchan, b, 0);
}
}
break;
case 4: /* Program change */
a &= 0x7f;
MIDIEVENT(song->at, ME_PROGRAM, lastchan, a, 0);
case 5: /* Channel pressure - NOT IMPLEMENTED */
break;
case 6: /* Pitch wheel */
SDL_RWread(song->rw, &b, 1, 1);
b &= 0x7F;
MIDIEVENT(song->at, ME_PITCHWHEEL, lastchan, a, b);
default:
SNDDBG(("*** Can't happen: status 0x%02X, channel 0x%02X\n",
laststatus, lastchan));
break;
}
}
}
return new;
}
#undef MIDIEVENT
/* Read a midi track into the linked list, either merging with any previous
tracks or appending to them. */
static int read_track(MidiSong *song, int append)
{
MidiEventList *meep;
MidiEventList *next, *new;
Sint32 len;
Sint64 next_pos, pos;
char tmp[4];
meep = song->evlist;
if (append && meep)
{
/* find the last event in the list */
for (; meep->next; meep=meep->next)
;
song->at = meep->event.time;
}
else
song->at=0;
/* Check the formalities */
if (SDL_RWread(song->rw, tmp, 1, 4) != 4 || SDL_RWread(song->rw, &len, 4, 1) != 1)
{
SNDDBG(("Can't read track header.\n"));
return -1;
}
len=SDL_SwapBE32(len);
next_pos = SDL_RWtell(song->rw) + len;
if (memcmp(tmp, "MTrk", 4))
{
SNDDBG(("Corrupt MIDI file.\n"));
return -2;
}
for (;;)
{
if (!(new=read_midi_event(song))) /* Some kind of error */
return -2;
if (new==MAGIC_EOT) /* End-of-track Hack. */
{
pos = SDL_RWtell(song->rw);
if (pos < next_pos)
SDL_RWseek(song->rw, next_pos - pos, RW_SEEK_CUR);
return 0;
}
next=meep->next;
while (next && (next->event.time < new->event.time))
{
meep=next;
next=meep->next;
}
new->next=next;
meep->next=new;
song->event_count++; /* Count the event. (About one?) */
meep=new;
}
}
/* Free the linked event list from memory. */
static void free_midi_list(MidiSong *song)
{
MidiEventList *meep, *next;
if (!(meep = song->evlist)) return;
while (meep)
{
next=meep->next;
free(meep);
meep=next;
}
song->evlist=NULL;
}
/* Allocate an array of MidiEvents and fill it from the linked list of
events, marking used instruments for loading. Convert event times to
samples: handle tempo changes. Strip unnecessary events from the list.
Free the linked list. */
static MidiEvent *groom_list(MidiSong *song, Sint32 divisions,Sint32 *eventsp,
Sint32 *samplesp)
{
MidiEvent *groomed_list, *lp;
MidiEventList *meep;
Sint32 i, our_event_count, tempo, skip_this_event, new_value;
Sint32 sample_cum, samples_to_do, at, st, dt, counting_time;
int current_bank[MAXCHAN], current_set[MAXCHAN], current_program[MAXCHAN];
/* Or should each bank have its own current program? */
for (i=0; i<MAXCHAN; i++)
{
current_bank[i]=0;
current_set[i]=0;
current_program[i]=song->default_program;
}
tempo=500000;
compute_sample_increment(song, tempo, divisions);
/* This may allocate a bit more than we need */
groomed_list=lp=safe_malloc(sizeof(MidiEvent) * (song->event_count+1));
meep=song->evlist;
our_event_count=0;
st=at=sample_cum=0;
counting_time=2; /* We strip any silence before the first NOTE ON. */
for (i = 0; i < song->event_count; i++)
{
skip_this_event=0;
if (meep->event.type==ME_TEMPO)
{
skip_this_event=1;
}
else if (meep->event.channel >= MAXCHAN)
skip_this_event=1;
else switch (meep->event.type)
{
case ME_PROGRAM:
if (ISDRUMCHANNEL(song, meep->event.channel))
{
if (song->drumset[meep->event.a]) /* Is this a defined drumset? */
new_value=meep->event.a;
else
{
SNDDBG(("Drum set %d is undefined\n", meep->event.a));
new_value=meep->event.a=0;
}
if (current_set[meep->event.channel] != new_value)
current_set[meep->event.channel]=new_value;
else
skip_this_event=1;
}
else
{
new_value=meep->event.a;
if ((current_program[meep->event.channel] != SPECIAL_PROGRAM)
&& (current_program[meep->event.channel] != new_value))
current_program[meep->event.channel] = new_value;
else
skip_this_event=1;
}
break;
case ME_NOTEON:
if (counting_time)
counting_time=1;
if (ISDRUMCHANNEL(song, meep->event.channel))
{
/* Mark this instrument to be loaded */
if (!(song->drumset[current_set[meep->event.channel]]
->instrument[meep->event.a]))
song->drumset[current_set[meep->event.channel]]
->instrument[meep->event.a] = MAGIC_LOAD_INSTRUMENT;
}
else
{
if (current_program[meep->event.channel]==SPECIAL_PROGRAM)
break;
/* Mark this instrument to be loaded */
if (!(song->tonebank[current_bank[meep->event.channel]]
->instrument[current_program[meep->event.channel]]))
song->tonebank[current_bank[meep->event.channel]]
->instrument[current_program[meep->event.channel]] =
MAGIC_LOAD_INSTRUMENT;
}
break;
case ME_TONE_BANK:
if (ISDRUMCHANNEL(song, meep->event.channel))
{
skip_this_event=1;
break;
}
if (song->tonebank[meep->event.a]) /* Is this a defined tone bank? */
new_value=meep->event.a;
else
{
SNDDBG(("Tone bank %d is undefined\n", meep->event.a));
new_value=meep->event.a=0;
}
if (current_bank[meep->event.channel]!=new_value)
current_bank[meep->event.channel]=new_value;
else
skip_this_event=1;
break;
}
/* Recompute time in samples*/
if ((dt=meep->event.time - at) && !counting_time)
{
if (song->sample_increment > 2147483647/dt ||
song->sample_correction > 2147483647/dt) {
goto _overflow;
}
samples_to_do = song->sample_increment * dt;
sample_cum += song->sample_correction * dt;
if (sample_cum & 0xFFFF0000)
{
samples_to_do += ((sample_cum >> 16) & 0xFFFF);
sample_cum &= 0x0000FFFF;
}
if (st >= 2147483647 - samples_to_do) {
_overflow:
SNDDBG(("Overflow in sample counter\n"));
free_midi_list(song);
free(groomed_list);
return NULL;
}
st += samples_to_do;
}
else if (counting_time==1) counting_time=0;
if (meep->event.type==ME_TEMPO)
{
tempo=
meep->event.channel + meep->event.b * 256 + meep->event.a * 65536;
compute_sample_increment(song, tempo, divisions);
}
if (!skip_this_event)
{
/* Add the event to the list */
*lp=meep->event;
lp->time=st;
lp++;
our_event_count++;
}
at=meep->event.time;
meep=meep->next;
}
/* Add an End-of-Track event */
lp->time=st;
lp->type=ME_EOT;
our_event_count++;
free_midi_list(song);
*eventsp=our_event_count;
*samplesp=st;
return groomed_list;
}
MidiEvent *read_midi_file(MidiSong *song, Sint32 *count, Sint32 *sp)
{
Sint32 len, divisions;
Sint16 format, tracks, divisions_tmp;
int i;
char tmp[4];
song->event_count=0;
song->at=0;
song->evlist = NULL;
if (SDL_RWread(song->rw, tmp, 1, 4) != 4 || SDL_RWread(song->rw, &len, 4, 1) != 1)
{
SNDDBG(("Not a MIDI file!\n"));
return NULL;
}
if (memcmp(tmp, "RIFF", 4) == 0) { /* RMID ?? */
if (SDL_RWread(song->rw, tmp, 1, 4) != 4 || memcmp(tmp, "RMID", 4) != 0 ||
SDL_RWread(song->rw, tmp, 1, 4) != 4 || memcmp(tmp, "data", 4) != 0 ||
SDL_RWread(song->rw, tmp, 1, 4) != 4 ||
/* SMF must begin from here onwards: */
SDL_RWread(song->rw, tmp, 1, 4) != 4 || SDL_RWread(song->rw, &len, 4, 1) != 1)
{
SNDDBG(("Not an RMID file!\n"));
return NULL;
}
}
len=SDL_SwapBE32(len);
if (memcmp(tmp, "MThd", 4) || len < 6)
{
SNDDBG(("Not a MIDI file!\n"));
return NULL;
}
SDL_RWread(song->rw, &format, 2, 1);
SDL_RWread(song->rw, &tracks, 2, 1);
SDL_RWread(song->rw, &divisions_tmp, 2, 1);
format=SDL_SwapBE16(format);
tracks=SDL_SwapBE16(tracks);
divisions_tmp=SDL_SwapBE16(divisions_tmp);
if (divisions_tmp<0)
{
/* SMPTE time -- totally untested. Got a MIDI file that uses this? */
divisions=
(Sint32)(-(divisions_tmp/256)) * (Sint32)(divisions_tmp & 0xFF);
}
else divisions=(Sint32)(divisions_tmp);
if (len > 6)
{
SNDDBG(("MIDI file header size %u bytes", len));
SDL_RWseek(song->rw, len-6, RW_SEEK_CUR); /* skip the excess */
}
if (format<0 || format >2)
{
SNDDBG(("Unknown MIDI file format %d\n", format));
return NULL;
}
if (tracks<1)
{
SNDDBG(("Bad number of tracks %d\n", tracks));
return NULL;
}
if (format==0 && tracks!=1)
{
SNDDBG(("%d tracks with Type-0 MIDI (must be 1.)\n", tracks));
return NULL;
}
SNDDBG(("Format: %d Tracks: %d Divisions: %d\n",
format, tracks, divisions));
/* Put a do-nothing event first in the list for easier processing */
song->evlist=safe_malloc(sizeof(MidiEventList));
memset(song->evlist, 0, sizeof(MidiEventList));
song->event_count++;
switch(format)
{
case 0:
if (read_track(song, 0))
{
free_midi_list(song);
return NULL;
}
break;
case 1:
for (i=0; i<tracks; i++)
if (read_track(song, 0))
{
free_midi_list(song);
return NULL;
}
break;
case 2: /* We simply play the tracks sequentially */
for (i=0; i<tracks; i++)
if (read_track(song, 1))
{
free_midi_list(song);
return NULL;
}
break;
}
return groom_list(song, divisions, count, sp);
}