load_med.c

wince下著名的视频播放器源码

/*	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_med.c,v 1.1.1.1 2004/01/21 01:36:35 raph Exp $

  Amiga MED module loader

==============================================================================*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#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 information */

typedef struct MEDHEADER {
	ULONG id;
	ULONG modlen;
	ULONG MEDSONGP;				/* struct MEDSONG *song; */
	UWORD psecnum;				/* for the player routine, MMD2 only */
	UWORD pseq;					/*  "   "   "   " */
	ULONG MEDBlockPP;			/* struct MEDBlock **blockarr; */
	ULONG reserved1;
	ULONG MEDINSTHEADERPP;		/* struct MEDINSTHEADER **smplarr; */
	ULONG reserved2;
	ULONG MEDEXPP;				/* struct MEDEXP *expdata; */
	ULONG reserved3;
	UWORD pstate;				/* some data for the player routine */
	UWORD pblock;
	UWORD pline;
	UWORD pseqnum;
	SWORD actplayline;
	UBYTE counter;
	UBYTE extra_songs;			/* number of songs - 1 */
} MEDHEADER;

typedef struct MEDSAMPLE {
	UWORD rep, replen;			/* offs: 0(s), 2(s) */
	UBYTE midich;				/* offs: 4(s) */
	UBYTE midipreset;			/* offs: 5(s) */
	UBYTE svol;					/* offs: 6(s) */
	SBYTE strans;				/* offs: 7(s) */
} MEDSAMPLE;

typedef struct MEDSONG {
	MEDSAMPLE sample[63];		/* 63 * 8 bytes = 504 bytes */
	UWORD numblocks;			/* offs: 504 */
	UWORD songlen;				/* offs: 506 */
	UBYTE playseq[256];			/* offs: 508 */
	UWORD deftempo;				/* offs: 764 */
	SBYTE playtransp;			/* offs: 766 */
	UBYTE flags;				/* offs: 767 */
	UBYTE flags2;				/* offs: 768 */
	UBYTE tempo2;				/* offs: 769 */
	UBYTE trkvol[16];			/* offs: 770 */
	UBYTE mastervol;			/* offs: 786 */
	UBYTE numsamples;			/* offs: 787 */
} MEDSONG;

typedef struct MEDEXP {
	ULONG nextmod;				/* pointer to next module */
	ULONG exp_smp;				/* pointer to MEDINSTEXT array */
	UWORD s_ext_entries;
	UWORD s_ext_entrsz;
	ULONG annotxt;				/* pointer to annotation text */
	ULONG annolen;
	ULONG iinfo;				/* pointer to MEDINSTINFO array */
	UWORD i_ext_entries;
	UWORD i_ext_entrsz;
	ULONG jumpmask;
	ULONG rgbtable;
	ULONG channelsplit;
	ULONG n_info;
	ULONG songname;				/* pointer to songname */
	ULONG songnamelen;
	ULONG dumps;
	ULONG reserved2[7];
} MEDEXP;

typedef struct MMD0NOTE {
	UBYTE a, b, c;
} MMD0NOTE;

typedef struct MMD1NOTE {
	UBYTE a, b, c, d;
} MMD1NOTE;

typedef struct MEDINSTHEADER {
	ULONG length;
	SWORD type;
	/* Followed by actual data */
} MEDINSTHEADER;

typedef struct MEDINSTEXT {
	UBYTE hold;
	UBYTE decay;
	UBYTE suppress_midi_off;
	SBYTE finetune;
} MEDINSTEXT;

typedef struct MEDINSTINFO {
	UBYTE name[40];
} MEDINSTINFO;

/*========== Loader variables */

#define MMD0_string 0x4D4D4430
#define MMD1_string 0x4D4D4431

static MEDHEADER *mh = NULL;
static MEDSONG *ms = NULL;
static MEDEXP *me = NULL;
static ULONG *ba = NULL;
static MMD0NOTE *mmd0pat = NULL;
static MMD1NOTE *mmd1pat = NULL;

static BOOL decimalvolumes;
static BOOL bpmtempos;

#define d0note(row,col) mmd0pat[((row)*(UWORD)of.numchn)+(col)]
#define d1note(row,col) mmd1pat[((row)*(UWORD)of.numchn)+(col)]

static CHAR MED_Version[] = "OctaMED (MMDx)";

/*========== Loader code */

BOOL MED_Test(void)
{
	UBYTE id[4];

	if (!_mm_read_UBYTES(id, 4, modreader))
		return 0;
	if ((!memcmp(id, "MMD0", 4)) || (!memcmp(id, "MMD1", 4)))
		return 1;
	return 0;
}

BOOL MED_Init(void)
{
	if (!(me = (MEDEXP *)_mm_malloc(sizeof(MEDEXP))))
		return 0;
	if (!(mh = (MEDHEADER *)_mm_malloc(sizeof(MEDHEADER))))
		return 0;
	if (!(ms = (MEDSONG *)_mm_malloc(sizeof(MEDSONG))))
		return 0;
	return 1;
}

void MED_Cleanup(void)
{
	_mm_free(me);
	_mm_free(mh);
	_mm_free(ms);
	_mm_free(ba);
	_mm_free(mmd0pat);
	_mm_free(mmd1pat);
}

static void EffectCvt(UBYTE eff, UBYTE dat)
{
	switch (eff) {
		/* 0x0 0x1 0x2 0x3 0x4 PT effects */
	  case 0x5:				/* PT vibrato with speed/depth nibbles swapped */
		UniPTEffect(0x4, (dat >> 4) | ((dat & 0xf) << 4));
		break;
		/* 0x6 0x7 not used */
	  case 0x6:
	  case 0x7:
		break;
	  case 0x8:				/* midi hold/decay */
		break;
	  case 0x9:
		if (bpmtempos) {
			if (!dat)
				dat = of.initspeed;
			UniEffect(UNI_S3MEFFECTA, dat);
		} else {
			if (dat <= 0x20) {
				if (!dat)
					dat = of.initspeed;
				else
					dat /= 4;
				UniPTEffect(0xf, dat);
			} else
				UniEffect(UNI_MEDSPEED, ((UWORD)dat * 125) / (33 * 4));
		}
		break;
		/* 0xa 0xb PT effects */
	  case 0xc:
		if (decimalvolumes)
			dat = (dat >> 4) * 10 + (dat & 0xf);
		UniPTEffect(0xc, dat);
		break;
	  case 0xd:				/* same as PT volslide */
		UniPTEffect(0xa, dat);
		break;
	  case 0xe:				/* synth jmp - midi */
		break;
	  case 0xf:
		switch (dat) {
		  case 0:				/* patternbreak */
			UniPTEffect(0xd, 0);
			break;
		  case 0xf1:			/* play note twice */
			UniWriteByte(UNI_MEDEFFECTF1);
			break;
		  case 0xf2:			/* delay note */
			UniWriteByte(UNI_MEDEFFECTF2);
			break;
		  case 0xf3:			/* play note three times */
			UniWriteByte(UNI_MEDEFFECTF3);
			break;
		  case 0xfe:			/* stop playing */
			UniPTEffect(0xb, of.numpat);
			break;
		  case 0xff:			/* note cut */
			UniPTEffect(0xc, 0);
			break;
		  default:
			if (dat <= 10)
				UniPTEffect(0xf, dat);
			else if (dat <= 240) {
				if (bpmtempos)
					UniPTEffect(0xf, (dat < 32) ? 32 : dat);
				else
					UniEffect(UNI_MEDSPEED, ((UWORD)dat * 125) / 33);
			}
		}
		break;
	  default:					/* all normal PT effects are handled here */
		UniPTEffect(eff, dat);
		break;
	}
}

static UBYTE *MED_Convert1(int count, int col)
{
	int t;
	UBYTE inst, note, eff, dat;
	MMD1NOTE *n;

	UniReset();
	for (t = 0; t < count; t++) {
		n = &d1note(t, col);

		note = n->a & 0x7f;
		inst = n->b & 0x3f;
		eff = n->c & 0xf;
		dat = n->d;

		if (inst)
			UniInstrument(inst - 1);
		if (note)
			UniNote(note + 3 * OCTAVE - 1);
		EffectCvt(eff, dat);
		UniNewline();
	}
	return UniDup();
}

static UBYTE *MED_Convert0(int count, int col)
{
	int t;
	UBYTE a, b, inst, note, eff, dat;
	MMD0NOTE *n;

	UniReset();
	for (t = 0; t < count; t++) {
		n = &d0note(t, col);
		a = n->a;
		b = n->b;

		note = a & 0x3f;
		a >>= 6;
		a = ((a & 1) << 1) | (a >> 1);
		inst = (b >> 4) | (a << 4);
		eff = b & 0xf;
		dat = n->c;

		if (inst)
			UniInstrument(inst - 1);
		if (note)
			UniNote(note + 3 * OCTAVE - 1);
		EffectCvt(eff, dat);
		UniNewline();
	}
	return UniDup();
}

static BOOL LoadMEDPatterns(void)
{
	int t, row, col;
	UWORD numtracks, numlines, maxlines = 0, track = 0;
	MMD0NOTE *mmdp;

	/* first, scan patterns to see how many channels are used */
	for (t = 0; t < of.numpat; t++) {
		_mm_fseek(modreader, ba[t], SEEK_SET);
		numtracks = _mm_read_UBYTE(modreader);
		numlines = _mm_read_UBYTE(modreader);

		if (numtracks > of.numchn)
			of.numchn = numtracks;
		if (numlines > maxlines)
			maxlines = numlines;
	}

	of.numtrk = of.numpat * of.numchn;
	if (!AllocTracks())
		return 0;
	if (!AllocPatterns())
		return 0;

	if (!
		(mmd0pat =
		 (MMD0NOTE *)_mm_calloc(of.numchn * (maxlines + 1),
								sizeof(MMD0NOTE)))) return 0;

	/* second read: read and convert patterns */
	for (t = 0; t < of.numpat; t++) {
		_mm_fseek(modreader, ba[t], SEEK_SET);
		numtracks = _mm_read_UBYTE(modreader);
		numlines = _mm_read_UBYTE(modreader);

		of.pattrows[t] = ++numlines;