📄 load_mod.c
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/* MikMod sound library
(c) 1998, 1999, 2000, 2001, 2002 Miodrag Vallat and others - see file
AUTHORS for complete list.
This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.
*/
/*==============================================================================
$Id: load_mod.c,v 1.2 2004/01/21 13:33:11 raph Exp $
Generic MOD loader (Protracker, StarTracker, FastTracker, etc)
==============================================================================*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <stdio.h>
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#include <string.h>
#include "mikmod_internals.h"
#ifdef SUNOS
extern int fprintf(FILE *, const char *, ...);
#endif
/*========== Module structure */
typedef struct MSAMPINFO {
CHAR samplename[23]; /* 22 in module, 23 in memory */
UWORD length;
UBYTE finetune;
UBYTE volume;
UWORD reppos;
UWORD replen;
} MSAMPINFO;
typedef struct MODULEHEADER {
CHAR songname[21]; /* the songname.. 20 in module, 21 in memory */
MSAMPINFO samples[31]; /* all sampleinfo */
UBYTE songlength; /* number of patterns used */
UBYTE magic1; /* should be 127 */
UBYTE positions[128]; /* which pattern to play at pos */
UBYTE magic2[4]; /* string "M.K." or "FLT4" or "FLT8" */
} MODULEHEADER;
typedef struct MODTYPE {
CHAR id[5];
UBYTE channels;
CHAR *name;
} MODTYPE;
typedef struct MODNOTE {
UBYTE a, b, c, d;
} MODNOTE;
/*========== Loader variables */
#define MODULEHEADERSIZE 0x438
static CHAR protracker[] = "Protracker";
static CHAR startrekker[] = "Startrekker";
static CHAR fasttracker[] = "Fasttracker";
static CHAR oktalyser[] = "Oktalyser";
static CHAR oktalyzer[] = "Oktalyzer";
static CHAR taketracker[] = "TakeTracker";
static CHAR orpheus[] = "Imago Orpheus (MOD format)";
static MODULEHEADER *mh = NULL;
static MODNOTE *patbuf = NULL;
static int modtype, trekker;
/*========== Loader code */
/* given the module ID, determine the number of channels and the tracker
description ; also alters modtype */
static BOOL MOD_CheckType(UBYTE *id, UBYTE *numchn, CHAR **descr)
{
modtype = trekker = 0;
/* Protracker and variants */
if ((!memcmp(id, "M.K.", 4)) || (!memcmp(id, "M!K!", 4))) {
*descr = protracker;
modtype = 0;
*numchn = 4;
return 1;
}
/* Star Tracker */
if (((!memcmp(id, "FLT", 3)) || (!memcmp(id, "EXO", 3))) &&
(isdigit(id[3]))) {
*descr = startrekker;
modtype = trekker = 1;
*numchn = id[3] - '0';
if (*numchn == 4 || *numchn == 8)
return 1;
#ifdef MIKMOD_DEBUG
else
fprintf(stderr, "\rUnknown FLT%d module type\n", *numchn);
#endif
return 0;
}
/* Oktalyzer (Amiga) */
if (!memcmp(id, "OKTA", 4)) {
*descr = oktalyzer;
modtype = 1;
*numchn = 8;
return 1;
}
/* Oktalyser (Atari) */
if (!memcmp(id, "CD81", 4)) {
*descr = oktalyser;
modtype = 1;
*numchn = 8;
return 1;
}
/* Fasttracker */
if ((!memcmp(id + 1, "CHN", 3)) && (isdigit(id[0]))) {
*descr = fasttracker;
modtype = 1;
*numchn = id[0] - '0';
return 1;
}
/* Fasttracker or Taketracker */
if (((!memcmp(id + 2, "CH", 2)) || (!memcmp(id + 2, "CN", 2)))
&& (isdigit(id[0])) && (isdigit(id[1]))) {
if (id[3] == 'H') {
*descr = fasttracker;
modtype = 2; /* this can also be Imago Orpheus */
} else {
*descr = taketracker;
modtype = 1;
}
*numchn = (id[0] - '0') * 10 + (id[1] - '0');
return 1;
}
return 0;
}
static BOOL MOD_Test(void)
{
UBYTE id[4], numchn;
CHAR *descr;
_mm_fseek(modreader, MODULEHEADERSIZE, SEEK_SET);
if (!_mm_read_UBYTES(id, 4, modreader))
return 0;
if (MOD_CheckType(id, &numchn, &descr))
return 1;
return 0;
}
static BOOL MOD_Init(void)
{
if (!(mh = (MODULEHEADER *)_mm_malloc(sizeof(MODULEHEADER))))
return 0;
return 1;
}
static void MOD_Cleanup(void)
{
_mm_free(mh);
_mm_free(patbuf);
}
/*
Old (amiga) noteinfo:
_____byte 1_____ byte2_ _____byte 3_____ byte4_
/ \ / \ / \ / \
0000 0000-00000000 0000 0000-00000000
Upper four 12 bits for Lower four Effect command.
bits of sam- note period. bits of sam-
ple number. ple number.
*/
static UBYTE ConvertNote(MODNOTE *n, UBYTE lasteffect)
{
UBYTE instrument, effect, effdat, note;
UWORD period;
UBYTE lastnote = 0;
/* extract the various information from the 4 bytes that make up a note */
instrument = (n->a & 0x10) | (n->c >> 4);
period = (((UWORD)n->a & 0xf) << 8) + n->b;
effect = n->c & 0xf;
effdat = n->d;
/* Convert the period to a note number */
note = 0;
if (period) {
for (note = 0; note < 7 * OCTAVE; note++)
if (period >= npertab[note])
break;
if (note == 7 * OCTAVE)
note = 0;
else
note++;
}
if (instrument) {
/* if instrument does not exist, note cut */
if ((instrument > 31) || (!mh->samples[instrument - 1].length)) {
UniPTEffect(0xc, 0);
if (effect == 0xc)
effect = effdat = 0;
} else {
/* Protracker handling */
if (!modtype) {
/* if we had a note, then change instrument... */
if (note)
UniInstrument(instrument - 1);
/* ...otherwise, only adjust volume... */
else {
/* ...unless an effect was specified, which forces a new
note to be played */
if (effect || effdat) {
UniInstrument(instrument - 1);
note = lastnote;
} else
UniPTEffect(0xc,
mh->samples[instrument -
1].volume & 0x7f);
}
} else {
/* Fasttracker handling */
UniInstrument(instrument - 1);
if (!note)
note = lastnote;
}
}
}
if (note) {
UniNote(note + 2 * OCTAVE - 1);
lastnote = note;
}
/* Convert pattern jump from Dec to Hex */
if (effect == 0xd)
effdat = (((effdat & 0xf0) >> 4) * 10) + (effdat & 0xf);
/* Volume slide, up has priority */
if ((effect == 0xa) && (effdat & 0xf) && (effdat & 0xf0))
effdat &= 0xf0;
/* Handle ``heavy'' volumes correctly */
if ((effect == 0xc) && (effdat > 0x40))
effdat = 0x40;
/* An isolated 100, 200 or 300 effect should be ignored (no
"standalone" porta memory in mod files). However, a sequence such
as 1XX, 100, 100, 100 is fine. */
if ((!effdat) && ((effect == 1)||(effect == 2)||(effect ==3)) &&
(lasteffect < 0x10) && (effect != lasteffect))
effect = 0;
UniPTEffect(effect, effdat);
if (effect == 8)
of.flags |= UF_PANNING;
return effect;
}
static UBYTE *ConvertTrack(MODNOTE *n, int numchn)
{
int t;
UBYTE lasteffect = 0x10; /* non existant effect */
UniReset();
for (t = 0; t < 64; t++) {
lasteffect = ConvertNote(n,lasteffect);
UniNewline();
n += numchn;
}
return UniDup();
}
/* Loads all patterns of a modfile and converts them into the 3 byte format. */
static BOOL ML_LoadPatterns(void)
{
int t, s, tracks = 0;
if (!AllocPatterns())
return 0;
if (!AllocTracks())
return 0;
/* Allocate temporary buffer for loading and converting the patterns */
if (!(patbuf = (MODNOTE *)_mm_calloc(64U * of.numchn, sizeof(MODNOTE))))
return 0;
if (trekker && of.numchn == 8) {
/* Startrekker module dual pattern */
for (t = 0; t < of.numpat; t++) {
for (s = 0; s < (64U * 4); s++) {
patbuf[s].a = _mm_read_UBYTE(modreader);
patbuf[s].b = _mm_read_UBYTE(modreader);
patbuf[s].c = _mm_read_UBYTE(modreader);
patbuf[s].d = _mm_read_UBYTE(modreader);
}
for (s = 0; s < 4; s++)
if (!(of.tracks[tracks++] = ConvertTrack(patbuf + s, 4)))
return 0;
for (s = 0; s < (64U * 4); s++) {
patbuf[s].a = _mm_read_UBYTE(modreader);
patbuf[s].b = _mm_read_UBYTE(modreader);
patbuf[s].c = _mm_read_UBYTE(modreader);
patbuf[s].d = _mm_read_UBYTE(modreader);
}
for (s = 0; s < 4; s++)
if (!(of.tracks[tracks++] = ConvertTrack(patbuf + s, 4)))
return 0;
}
} else {
/* Generic module pattern */
for (t = 0; t < of.numpat; t++) {
/* Load the pattern into the temp buffer and convert it */
for (s = 0; s < (64U * of.numchn); s++) {
patbuf[s].a = _mm_read_UBYTE(modreader);
patbuf[s].b = _mm_read_UBYTE(modreader);
patbuf[s].c = _mm_read_UBYTE(modreader);
patbuf[s].d = _mm_read_UBYTE(modreader);
}
for (s = 0; s < of.numchn; s++)
if (!(of.tracks[tracks++] = ConvertTrack(patbuf + s, of.numchn)))
return 0;
}
}
return 1;
}
static BOOL MOD_Load(BOOL curious)
{
int t, scan;
SAMPLE *q;
MSAMPINFO *s;
CHAR *descr;
/* try to read module header */
_mm_read_string((CHAR *)mh->songname, 20, modreader);
mh->songname[20] = 0; /* just in case */
for (t = 0; t < 31; t++) {
s = &mh->samples[t];
_mm_read_string(s->samplename, 22, modreader);
s->samplename[22] = 0; /* just in case */
s->length = _mm_read_M_UWORD(modreader);
s->finetune = _mm_read_UBYTE(modreader);
s->volume = _mm_read_UBYTE(modreader);
s->reppos = _mm_read_M_UWORD(modreader);
s->replen = _mm_read_M_UWORD(modreader);
}
mh->songlength = _mm_read_UBYTE(modreader);
/* this fixes mods which declare more than 128 positions.
* eg: beatwave.mod */
if (mh->songlength > 128) { mh->songlength = 128; }
mh->magic1 = _mm_read_UBYTE(modreader);
_mm_read_UBYTES(mh->positions, 128, modreader);
_mm_read_UBYTES(mh->magic2, 4, modreader);
if (_mm_eof(modreader)) {
_mm_errno = MMERR_LOADING_HEADER;
return 0;
}
/* set module variables */
of.initspeed = 6;
of.inittempo = 125;
if (!(MOD_CheckType(mh->magic2, &of.numchn, &descr))) {
_mm_errno = MMERR_NOT_A_MODULE;
return 0;
}
if (trekker && of.numchn == 8)
for (t = 0; t < 128; t++)
/* if module pretends to be FLT8, yet the order table
contains odd numbers, chances are it's a lying FLT4... */
if (mh->positions[t] & 1) {
of.numchn = 4;
break;
}
if (trekker && of.numchn == 8)
for (t = 0; t < 128; t++)
mh->positions[t] >>= 1;
of.songname = DupStr(mh->songname, 21, 1);
of.numpos = mh->songlength;
of.reppos = 0;
/* Count the number of patterns */
of.numpat = 0;
for (t = 0; t < of.numpos; t++)
if (mh->positions[t] > of.numpat)
of.numpat = mh->positions[t];
/* since some old modules embed extra patterns, we have to check the
whole list to get the samples' file offsets right - however we can find
garbage here, so check carefully */
scan = 1;
for (t = of.numpos; t < 128; t++)
if (mh->positions[t] >= 0x80)
scan = 0;
if (scan)
for (t = of.numpos; t < 128; t++) {
if (mh->positions[t] > of.numpat)
of.numpat = mh->positions[t];
if ((curious) && (mh->positions[t]))
of.numpos = t + 1;
}
of.numpat++;
of.numtrk = of.numpat * of.numchn;
if (!AllocPositions(of.numpos))
return 0;
for (t = 0; t < of.numpos; t++)
of.positions[t] = mh->positions[t];
/* Finally, init the sampleinfo structures */
of.numins = of.numsmp = 31;
if (!AllocSamples())
return 0;
s = mh->samples;
q = of.samples;
for (t = 0; t < of.numins; t++) {
/* convert the samplename */
q->samplename = DupStr(s->samplename, 23, 1);
/* init the sampleinfo variables and convert the size pointers */
q->speed = finetune[s->finetune & 0xf];
q->volume = s->volume & 0x7f;
q->loopstart = (ULONG)s->reppos << 1;
q->loopend = q->loopstart + ((ULONG)s->replen << 1);
q->length = (ULONG)s->length << 1;
q->flags = SF_SIGNED;
/* Imago Orpheus creates MODs with 16 bit samples, check */
if ((modtype == 2) && (s->volume & 0x80)) {
q->flags |= SF_16BITS;
descr = orpheus;
}
if (s->replen > 2)
q->flags |= SF_LOOP;
s++;
q++;
}
of.modtype = strdup(descr);
if (!ML_LoadPatterns())
return 0;
return 1;
}
static CHAR *MOD_LoadTitle(void)
{
CHAR s[21];
_mm_fseek(modreader, 0, SEEK_SET);
if (!_mm_read_UBYTES(s, 20, modreader))
return NULL;
s[20] = 0; /* just in case */
return (DupStr(s, 21, 1));
}
/*========== Loader information */
MIKMODAPI MLOADER load_mod = {
NULL,
"Standard module",
"MOD (31 instruments)",
MOD_Init,
MOD_Test,
MOD_Load,
MOD_Cleanup,
MOD_LoadTitle
};
/* ex:set ts=4: */
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