reverb.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
*/

/*
 * REVERB EFFECT FOR TIMIDITY++-1.X (Version 0.06e  1999/1/28)
 * 
 * Copyright (C) 1997,1998,1999  Masaki Kiryu <[e-mail]>
 *                           (http://w3mb.kcom.ne.jp/~mkiryu/)
 *
 * reverb.c  -- main reverb engine.
 *
 */
#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 "controls.h"
#include "tables.h"
#include "common.h"
#include "output.h"
#include "reverb.h"
#include "mt19937ar.h"
#include <math.h>
#include <stdlib.h>

#define SYS_EFFECT_PRE_LPF

/* #define SYS_EFFECT_CLIP */
#ifdef SYS_EFFECT_CLIP
#define CLIP_AMP_MAX (1L << (32 - GUARD_BITS))
#define CLIP_AMP_MIN (-1L << (32 - GUARD_BITS))
#endif /* SYS_EFFECT_CLIP */

static double REV_INP_LEV = 1.0;
#define MASTER_CHORUS_LEVEL 1.7
#define MASTER_DELAY_LEVEL 3.25

/*              */
/*  Dry Signal  */
/*              */
static int32 direct_buffer[AUDIO_BUFFER_SIZE * 2];
static int32 direct_bufsize = sizeof(direct_buffer);

#if OPT_MODE != 0 && ( defined(_MSC_VER) || defined(__WATCOMC__)|| (defined(__BORLANDC__) && (__BORLANDC__ >= 1380)) )
void set_dry_signal(int32 *buf, int32 count)
{
	int32 *dbuf = direct_buffer;
	_asm {
		mov		ecx, [count]
		mov		esi, [buf]
		test	ecx, ecx
		jz		short L2
		mov		edi, [dbuf]
L1:		mov		eax, [esi]
		mov		ebx, [edi]
		add		esi, 4
		add		ebx, eax
		mov		[edi], ebx
		add		edi, 4
		dec		ecx
		jnz		L1
L2:
	}
}
#else
void set_dry_signal(register int32 *buf, int32 n)
{
#if USE_ALTIVEC
  if(is_altivec_available()) {
    v_set_dry_signal(direct_buffer, buf, n);
  } else {
#endif
    register int32 i;
	register int32 *dbuf = direct_buffer;

    for(i = n - 1; i >= 0; i--)
    {
        dbuf[i] += buf[i];
    }
#if USE_ALTIVEC
  }
#endif
}
#endif

/* XG has "dry level". */
#if OPT_MODE != 0	/* fixed-point implementation */
#if defined(_MSC_VER) || defined(__WATCOMC__) || (defined(__BORLANDC__) && (__BORLANDC__ >= 1380))
void set_dry_signal_xg(int32 *buf, int32 count, int32 level)
{
	int32 *dbuf = direct_buffer;
	if(!level) {return;}
	level = level * 65536 / 127;

	_asm {
		mov		ecx, [count]
		mov		esi, [buf]
		mov		ebx, [level]
		test	ecx, ecx
		jz		short L2
		mov		edi, [dbuf]
L1:		mov		eax, [esi]
		imul	ebx
		shr		eax, 16
		shl		edx, 16
		or		eax, edx	/* u */
		mov		edx, [edi]	/* v */
		add		esi, 4		/* u */	
		add		edx, eax	/* v */
		mov		[edi], edx	/* u */
		add		edi, 4		/* v */
		dec		ecx			/* u */
		jnz		L1			/* v */
L2:
	}
}
#else
void set_dry_signal_xg(register int32 *sbuffer, int32 n, int32 level)
{
    register int32 i;
	int32 *buf = direct_buffer;
	if(!level) {return;}
	level = level * 65536 / 127;

	for(i = n - 1; i >= 0; i--) {buf[i] += imuldiv16(sbuffer[i], level);}
}
#endif	/* _MSC_VER */
#else	/* floating-point implementation */
void set_dry_signal_xg(register int32 *sbuffer, int32 n, int32 level)
{
    register int32 i;
    register int32 count = n;
	if(!level) {return;}
    FLOAT_T send_level = (FLOAT_T)level / 127.0;

    for(i = 0; i < count; i++)
    {
		direct_buffer[i] += sbuffer[i] * send_level;
    }
}
#endif /* OPT_MODE != 0 */

#ifdef SYS_EFFECT_CLIP
void mix_dry_signal(int32 *buf, int32 n)
{
	int32 i, x;
	for (i = 0; i < n; i++) {
		x = direct_buffer[i];
		buf[i] = (x > CLIP_AMP_MAX) ? CLIP_AMP_MAX
				: (x < CLIP_AMP_MIN) ? CLIP_AMP_MIN : x;
	}
	memset(direct_buffer, 0, sizeof(int32) * n);
}
#else /* SYS_EFFECT_CLIP */
void mix_dry_signal(int32 *buf, int32 n)
{
 	memcpy(buf, direct_buffer, sizeof(int32) * n);
	memset(direct_buffer, 0, sizeof(int32) * n);
}
#endif /* SYS_EFFECT_CLIP */

/*                    */
/*  Effect Utilities  */
/*                    */
static inline int isprime(int val)
{
	int i;
	if (val == 2) {return 1;}
	if (val & 1) {
		for (i = 3; i < (int)sqrt((double)val) + 1; i += 2) {
			if ((val % i) == 0) {return 0;}
		}
		return 1; /* prime */
	} else {return 0;} /* even */
}

/*! delay */
static void free_delay(delay *delay)
{
	if(delay->buf != NULL) {
		free(delay->buf);
		delay->buf = NULL;
	}
}

static void set_delay(delay *delay, int32 size)
{
	if(size < 1) {size = 1;} 
	free_delay(delay);
	delay->buf = (int32 *)safe_malloc(sizeof(int32) * size);
	if(delay->buf == NULL) {return;}
	delay->index = 0;
	delay->size = size;
	memset(delay->buf, 0, sizeof(int32) * delay->size);
}

static inline void do_delay(int32 *stream, int32 *buf, int32 size, int32 *index)
{
	int32 output;
	output = buf[*index];
	buf[*index] = *stream;
	if (++*index >= size) {*index = 0;}
	*stream = output;
}

/*! LFO (low frequency oscillator) */
static void init_lfo(lfo *lfo, double freq, int type, double phase)
{
	int32 i, cycle, diff;

	lfo->count = 0;
	lfo->freq = freq;
	if (lfo->freq < 0.05f) {lfo->freq = 0.05f;}
	cycle = (double)play_mode->rate / lfo->freq;
	if (cycle < 1) {cycle = 1;}
	lfo->cycle = cycle;
	lfo->icycle = TIM_FSCALE((SINE_CYCLE_LENGTH - 1) / (double)cycle, 24) - 0.5;
	diff = SINE_CYCLE_LENGTH * phase / 360.0f;

	if(lfo->type != type) {	/* generate LFO waveform */
		switch(type) {
		case LFO_SINE:
			for(i = 0; i < SINE_CYCLE_LENGTH; i++)
				lfo->buf[i] = TIM_FSCALE((lookup_sine(i + diff) + 1.0) / 2.0, 16);
			break;
		case LFO_TRIANGULAR:
			for(i = 0; i < SINE_CYCLE_LENGTH; i++)
				lfo->buf[i] = TIM_FSCALE((lookup_triangular(i + diff) + 1.0) / 2.0, 16);
			break;
		default:
			for(i = 0; i < SINE_CYCLE_LENGTH; i++) {lfo->buf[i] = TIM_FSCALE(0.5, 16);}
			break;
		}
	}
	lfo->type = type;
}

/* returned value is between 0 and (1 << 16) */
static inline int32 do_lfo(lfo *lfo)
{
	int32 val;
	val = lfo->buf[imuldiv24(lfo->count, lfo->icycle)];
	if(++lfo->count == lfo->cycle) {lfo->count = 0;}
	return val;
}

/*! modulated delay with allpass interpolation (for Chorus Effect,...) */
static void free_mod_delay(mod_delay *delay)
{
	if(delay->buf != NULL) {
		free(delay->buf);
		delay->buf = NULL;
	}
}

static void set_mod_delay(mod_delay *delay, int32 ndelay, int32 depth)
{
	int32 size = ndelay + depth + 1;
	free_mod_delay(delay);
	delay->buf = (int32 *)safe_malloc(sizeof(int32) * size);
	if(delay->buf == NULL) {return;}
	delay->rindex = 0;
	delay->windex = 0;
	delay->hist = 0;
	delay->ndelay = ndelay;
	delay->depth = depth;
	delay->size = size;
	memset(delay->buf, 0, sizeof(int32) * delay->size);
}

static inline void do_mod_delay(int32 *stream, int32 *buf, int32 size, int32 *rindex, int32 *windex,
								int32 ndelay, int32 depth, int32 lfoval, int32 *hist)
{
	int32 t1, t2;
	if (++*windex == size) {*windex = 0;}
	t1 = buf[*rindex];
	t2 = imuldiv24(lfoval, depth);
	*rindex = *windex - ndelay - (t2 >> 8);
	if (*rindex < 0) {*rindex += size;}
	t2 = 0xFF - (t2 & 0xFF);
	*hist = t1 + imuldiv8(buf[*rindex] - *hist, t2);
	buf[*windex] = *stream;
	*stream = *hist;
}

/*! modulated allpass filter with allpass interpolation (for Plate Reverberator,...) */
static void free_mod_allpass(mod_allpass *delay)
{
	if(delay->buf != NULL) {
		free(delay->buf);
		delay->buf = NULL;
	}
}

static void set_mod_allpass(mod_allpass *delay, int32 ndelay, int32 depth, double feedback)
{
	int32 size = ndelay + depth + 1;
	free_mod_allpass(delay);
	delay->buf = (int32 *)safe_malloc(sizeof(int32) * size);
	if(delay->buf == NULL) {return;}
	delay->rindex = 0;
	delay->windex = 0;
	delay->hist = 0;
	delay->ndelay = ndelay;
	delay->depth = depth;
	delay->size = size;
	delay->feedback = feedback;
	delay->feedbacki = TIM_FSCALE(feedback, 24);
	memset(delay->buf, 0, sizeof(int32) * delay->size);
}

static inline void do_mod_allpass(int32 *stream, int32 *buf, int32 size, int32 *rindex, int32 *windex,
								  int32 ndelay, int32 depth, int32 lfoval, int32 *hist, int32 feedback)
{
	int t1, t2, t3;
	if (++*windex == size) {*windex = 0;}
	t3 = *stream + imuldiv24(*hist, feedback);
	t1 = buf[*rindex];
	t2 = imuldiv24(lfoval, depth);
	*rindex = *windex - ndelay - (t2 >> 8);
	if (*rindex < 0) {*rindex += size;}
	t2 = 0xFF - (t2 & 0xFF);
	*hist = t1 + imuldiv8(buf[*rindex] - *hist, t2);
	buf[*windex] = t3;
	*stream = *hist - imuldiv24(t3, feedback);
}

/* allpass filter */
static void free_allpass(allpass *allpass)
{
	if(allpass->buf != NULL) {
		free(allpass->buf);
		allpass->buf = NULL;
	}
}

static void set_allpass(allpass *allpass, int32 size, double feedback)
{
	if(allpass->buf != NULL) {
		free(allpass->buf);
		allpass->buf = NULL;
	}
	allpass->buf = (int32 *)safe_malloc(sizeof(int32) * size);
	if(allpass->buf == NULL) {return;}
	allpass->index = 0;
	allpass->size = size;
	allpass->feedback = feedback;
	allpass->feedbacki = TIM_FSCALE(feedback, 24);
	memset(allpass->buf, 0, sizeof(int32) * allpass->size);
}

static inline void do_allpass(int32 *stream, int32 *buf, int32 size, int32 *index, int32 feedback)
{
	int32 bufout, output;
	bufout = buf[*index];
	output = *stream - imuldiv24(bufout, feedback);
	buf[*index] = output;
	if (++*index >= size) {*index = 0;}
	*stream = bufout + imuldiv24(output, feedback);
}

static void init_filter_moog(filter_moog *svf)
{
	svf->b0 = svf->b1 = svf->b2 = svf->b3 = svf->b4 = 0;
}

/*! calculate Moog VCF coefficients */
void calc_filter_moog(filter_moog *svf)
{
	double res, fr, p, q, f;

	if (svf->freq > play_mode->rate / 2) {svf->freq = play_mode->rate / 2;}
	else if(svf->freq < 20) {svf->freq = 20;}

	if(svf->freq != svf->last_freq || svf->res_dB != svf->last_res_dB) {
		if(svf->last_freq == 0) {init_filter_moog(svf);}
		svf->last_freq = svf->freq, svf->last_res_dB = svf->res_dB;

		res = pow(10, (svf->res_dB - 96) / 20);
		fr = 2.0 * (double)svf->freq / (double)play_mode->rate;
		q = 1.0 - fr;
		p = fr + 0.8 * fr * q;
		f = p + p - 1.0;
		q = res * (1.0 + 0.5 * q * (1.0 - q + 5.6 * q * q));
		svf->f = TIM_FSCALE(f, 24);
		svf->p = TIM_FSCALE(p, 24);
		svf->q = TIM_FSCALE(q, 24);
	}
}

static inline void do_filter_moog(int32 *stream, int32 *high, int32 f, int32 p, int32 q,
								  int32 *b0, int32 *b1, int32 *b2, int32 *b3, int32 *b4)
{
	int32 t1, t2, t3, tb0 = *b0, tb1 = *b1, tb2 = *b2, tb3 = *b3, tb4 = *b4;
	t3 = *stream - imuldiv24(q, tb4);
	t1 = tb1;	tb1 = imuldiv24(t3 + tb0, p) - imuldiv24(tb1, f);
	t2 = tb2;	tb2 = imuldiv24(tb1 + t1, p) - imuldiv24(tb2, f);
	t1 = tb3;	tb3 = imuldiv24(tb2 + t2, p) - imuldiv24(tb3, f);
	*stream = tb4 = imuldiv24(tb3 + t1, p) - imuldiv24(tb4, f);