mod2midi.c

MIDI解码程序(用VC编写)

/*
    TiMidity++ -- MIDI to WAVE converter and player
    Copyright (C) 1999-2002 Masanao Izumo <[e-mail]>
    Copyright (C) 1995 Tuukka Toivonen <[e-mail]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    mod2midi.c

    Mixer event -> MIDI event conversion
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#ifndef NO_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif

#include "timidity.h"
#include "common.h"
#include "instrum.h"
#include "playmidi.h"
#include "readmidi.h"
#include "tables.h"
#include "mod.h"
#include "output.h"
#include "controls.h"
#include "unimod.h"
#include "mod2midi.h"
#include "filter.h"
#include "math.h"
#include "freq.h"


/* Define this to show all the notes touched by a bending in the
 * user interface's trace view.  This is interesting but disabled
 * because it needs tons of CPU power (tens of voices are activated
 * but unaudible). */
/* #define TRACE_SLIDE_NOTES */

/* Define this to give a volume envelope to a MOD's notes. This
 * could sound wrong with a few MODs, but gives richer sound most
 * of the time. */
#define USE_ENVELOPE


#define SETMIDIEVENT(e, at, t, ch, pa, pb) \
    { /* printf("%d %d " #t " %d %d\n", at, ch, pa, pb); */ \
      (e).time = (at); (e).type = (t); \
      (e).channel = (uint8)(ch); (e).a = (uint8)(pa); (e).b = (uint8)(pb); }

#define MIDIEVENT(at, t, ch, pa, pb) \
    { MidiEvent event; SETMIDIEVENT(event, at, t, ch, pa, pb); \
      readmidi_add_event(&event); }

/*
		   Clock
   SampleRate := ----------
		   Period
 */


#define NTSC_CLOCK 3579545.25
#define NTSC_RATE ((int32)(NTSC_CLOCK/428))

#define PAL_CLOCK 3546894.6
#define PAL_RATE ((int32)(PAL_CLOCK/428))

#define MOD_ROOT_NOTE      36

/* The internal bending register is 21-bits wide and it is made like this:
 *  _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
 * | | | | | | | | | | | | | | | | | | | | | |
 * |    8 bits     |    8 bits     |  5 bits |
 * |  note  shift  |   fine tune   |discarded|
 * '---------------'---------------'---------'
 *
 * The note shift is an `offset' field: 128 = keep this note.
 * To compute it, the values given to the pitch-wheel MIDI event are
 * multiplied by the sensitivity. We want to be able to express a full
 * 120 notes bending (8 bits for the note shift + 8 for the fine tune)
 * with 14-bit pitch-wheel event, so we want a sensitivity value that
 * forces the bottom 7 bits of the internal register to 0.  This value
 * is of course 128.
 */

#define WHEEL_SENSITIVITY 		(1 << 7)
#define WHEEL_VALUE(bend)		((bend) / WHEEL_SENSITIVITY + 0x2000)


typedef struct _ModVoice
  {
    int sample;			/* current sample ID */
    int noteon;			/* (-1 means OFF status) */
    int time;			/* time when note was activated */
    int period;			/* current frequency */
    int wheel;			/* current pitch wheel value */
    int pan;			/* current panning */
    int vol;			/* current volume */

    int32 noteson[4];		/* bit map for notes 0-127 */
  }
ModVoice;

static void mod_change_tempo (int32 at, int bpm);
static int period2note (int period, int *finetune);

static ModVoice ModV[MOD_NUM_VOICES];
static int at;

/******************** bitmap handling macros **********************************/

#define bitmapGet(map, n)	((map)[(n) >> 5] &  (1 << ((n) & 31)))
#define bitmapSet(map, n)	((map)[(n) >> 5] |= (1 << ((n) & 31)))
#define bitmapClear(map)	((map)[0] = (map)[1] = (map)[2] = (map)[3] = 0)

static char significantDigitsLessOne[256] = {
    -1,							/* 1 */
    0,							/* 2 */
    1, 1,						/* 4 */
    2, 2, 2, 2,						/* 8 */
    3, 3, 3, 3, 3, 3, 3, 3,				/* 16 */
    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,	/* 32 */

    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,	/* 64 */
    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,

    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,	/* 128 */
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,

    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,	/* 256 */
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
};

/******************************************************************************/

void
mod_change_tempo (int32 at, int bpm)
{
  int32 tempo;
  int c, a, b;

  tempo = 60000000 / bpm;
  c = (tempo & 0xff);
  a = ((tempo >> 8) & 0xff);
  b = ((tempo >> 16) & 0xff);
  MIDIEVENT (at, ME_TEMPO, c, b, a);
}

int
period2note (int period, int *finetune)
{
  static int period_table[121] =
  {
  /*  C     C#    D     D#    E     F     F#    G     G#    A     A#    B  */
     13696,12928,12192,11520,10848,10240, 9664, 9120, 8608, 8096, 7680, 7248,
      6848, 6464, 6096, 5760, 5424, 5120, 4832, 4560, 4304, 4048, 3840, 3624,
      3424, 3232, 3048, 2880, 2712, 2560, 2416, 2280, 2152, 2024, 1920, 1812,
      1712, 1616, 1524, 1440, 1356, 1280, 1208, 1140, 1076, 1016,  960,  906,
       856,  808,  762,  720,  678,  640,  604,  570,  538,  508,  480,  453,
       428,  404,  381,  360,  339,  320,  302,  285,  269,  254,  240,  226,
       214,  202,  190,  180,  170,  160,  151,  143,  135,  127,  120,  113,
       107,  101,   95,   90,   85,   80,   75,   71,   67,   63,   60,   56,
	53,   50,   47,   45,   42,   40,   37,   35,   33,   31,   30,   28,
	27,   25,   24,   22,   21,   20,   19,   18,   17,   16,   15,   14,
	  
	-100 /* just a guard */
  };

  int note;
  int l, r, m;

  if (period < 14 || period > 13696)
  {
    ctl->cmsg(CMSG_WARNING, VERB_NORMAL, "BAD period %d\n", period);
    return -1;
  }

  /* bin search */
  l = 0;
  r = 120;
  while (l < r)
    {
      m = (l + r) / 2;
      if (period_table[m] >= period)
	l = m + 1;
      else
	r = m;
    }
  note = l - 1;

  /*
   * 112 >= note >= 0
   * period_table[note] >= period > period_table[note + 1]
   */

  if (period_table[note] == period)
    *finetune = 0;
  else {
    /* Pick the closest note even if it is higher than this one.
     * (e.g. 721 - 720 < 762 - 721 ----> pick 720)    */
    if (period - period_table[note + 1] < period_table[note] - period)
      note++;
    
    /* fine tune completion */
    *finetune = ((period_table[note] - period) << 8) /
		   (period_table[note] - period_table[note + 1]);

    *finetune <<= 5;
  }
  return note;
}

/********** Interface to mod.c */

void
Voice_SetVolume (UBYTE v, UWORD vol)
{
  if (v >= MOD_NUM_VOICES)
    return;

  /* MOD volume --> MIDI volume */
  vol >>= 1;
  /* if (vol < 0) vol = 0; *//* UNSIGNED! */
  if (vol > 127) vol = 127;

  if (ModV[v].vol != vol) {
    ModV[v].vol = vol;
    MIDIEVENT (at, ME_EXPRESSION, v, vol, 0);
  }
}

void
Voice_SetPeriod (UBYTE v, ULONG period)
{
  int new_noteon, bend;

  if (v >= MOD_NUM_VOICES)
    return;

  ModV[v].period = period;
  if (ModV[v].noteon < 0)
    return;

  new_noteon = period2note (ModV[v].period, &bend);
#ifndef TRACE_SLIDE_NOTES
  bend += (new_noteon - ModV[v].noteon) << 13;
  new_noteon = ModV[v].noteon;
#endif
  bend = WHEEL_VALUE(bend);

  if (ModV[v].noteon != new_noteon)
    {
      MIDIEVENT(at, ME_KEYPRESSURE, v, ModV[v].noteon, 1);

      if (new_noteon < 0)
        {
	  ctl->cmsg(CMSG_WARNING, VERB_VERBOSE,
			  "Strange period %d",
			  ModV[v].period);
	  return;
	}
      else if (!bitmapGet(ModV[v].noteson, new_noteon))
	{
	  MIDIEVENT(ModV[v].time, ME_NOTEON, v, new_noteon, 1);
	  bitmapSet(ModV[v].noteson, new_noteon);
	}

    }

  if (ModV[v].wheel != bend)
    {
      ModV[v].wheel = bend;
      MIDIEVENT (at, ME_PITCHWHEEL, v, bend & 0x7F, (bend >> 7) & 0x7F);
    }

  if (ModV[v].noteon != new_noteon)
    {
      MIDIEVENT(at, ME_KEYPRESSURE, v, new_noteon, 127);
      ModV[v].noteon = new_noteon;
    }

}

void
Voice_SetPanning (UBYTE v, ULONG pan)
{
  if (v >= MOD_NUM_VOICES)
    return;
  if (pan == PAN_SURROUND)
    pan = PAN_CENTER; /* :-( */

  if (pan != ModV[v].pan) {
    ModV[v].pan = pan;
    MIDIEVENT(at, ME_PAN, v, pan * 127 / PAN_RIGHT, 0);
  }
}

void
Voice_Play (UBYTE v, SAMPLE * s, ULONG start)
{
  int new_noteon, bend;
  if (v >= MOD_NUM_VOICES)
    return;

  if (ModV[v].noteon != -1)
    Voice_Stop (v);

  new_noteon = period2note (ModV[v].period, &bend);
  bend = WHEEL_VALUE(bend);
  if (new_noteon < 0) {
    ctl->cmsg(CMSG_WARNING, VERB_VERBOSE,
			  "Strange period %d",
			  ModV[v].period);
    return;
  }

  ModV[v].noteon = new_noteon;
  ModV[v].time = at;
  bitmapSet(ModV[v].noteson, new_noteon);

  if (ModV[v].sample != s->id)
    {
      ModV[v].sample = s->id;
      MIDIEVENT(at, ME_SET_PATCH, v, ModV[v].sample, 0);
    }

  if (start > 0)
    {
      int a, b;