www.pudn.com > gspmidi101src.zip > resample.c
/*
TiMidity -- Experimental MIDI to WAVE converter
Copyright (C) 1995 Tuukka Toivonen
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., 675 Mass Ave, Cambridge, MA 02139, USA.
resample.c
*/
#include
#include
#include
#include "config.h"
#include "common.h"
#include "instrum.h"
#include "playmidi.h"
#include "output.h"
#include "tables.h"
#include "resample.h"
#ifdef LINEAR_INTERPOLATION
# if defined(LOOKUP_HACK) && defined(LOOKUP_INTERPOLATION)
# define RESAMPLATION \
v1=src[ofs>>FRACTION_BITS];\
v2=src[(ofs>>FRACTION_BITS)+1];\
*dest++ = v1 + (iplookup[(((v2-v1)<<5) & 0x03FE0) | \
((ofs & FRACTION_MASK) >> (FRACTION_BITS-5))]);
# else
# define RESAMPLATION \
v1=src[ofs>>FRACTION_BITS];\
v2=src[(ofs>>FRACTION_BITS)+1];\
*dest++ = v1 + (((v2-v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS);
# endif
# define INTERPVARS sample_t v1, v2
#else
/* Earplugs recommended for maximum listening enjoyment */
# define RESAMPLATION *dest++=src[ofs>>FRACTION_BITS];
# define INTERPVARS
#endif
#define FINALINTERP if (ofs == le) *dest++=src[(ofs>>FRACTION_BITS)-1]/2;
/* So it isn't interpolation. At least it's final. */
static sample_t resample_buffer[AUDIO_BUFFER_SIZE];
/*************** resampling with fixed increment *****************/
static sample_t *rs_plain(int v, int32 *countptr)
{
/* Play sample until end, then free the voice. */
INTERPVARS;
Voice
*vp=&voice[v];
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
int32
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->data_length,
count=*countptr;
#ifdef PRECALC_LOOPS
int32 i;
if (incr<0) incr = -incr; /* In case we're coming out of a bidir loop */
/* Precalc how many times we should go through the loop.
NOTE: Assumes that incr > 0 and that ofs <= le */
i = (le - ofs) / incr + 1;
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
if (ofs >= le)
{
FINALINTERP;
vp->status=VOICE_FREE;
*countptr-=count+1;
}
#else /* PRECALC_LOOPS */
while (count--)
{
RESAMPLATION;
ofs += incr;
if (ofs >= le)
{
FINALINTERP;
vp->status=VOICE_FREE;
ctl->note(v);
*countptr-=count+1;
break;
}
}
#endif /* PRECALC_LOOPS */
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
static sample_t *rs_loop(Voice *vp, int32 count)
{
/* Play sample until end-of-loop, skip back and continue. */
INTERPVARS;
int32
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ll=le - vp->sample->loop_start;
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
#ifdef PRECALC_LOOPS
int32 i;
while (count)
{
while (ofs >= le)
ofs -= ll;
/* Precalc how many times we should go through the loop */
i = (le - ofs) / incr + 1;
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
}
#else
while (count--)
{
RESAMPLATION;
ofs += incr;
if (ofs>=le)
ofs -= ll; /* Hopefully the loop is longer than an increment. */
}
#endif
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
static sample_t *rs_bidir(Voice *vp, int32 count)
{
INTERPVARS;
int32
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ls=vp->sample->loop_start;
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
#ifdef PRECALC_LOOPS
int32
le2 = le<<1,
ls2 = ls<<1,
i;
/* Play normally until inside the loop region */
if (ofs <= ls)
{
/* NOTE: Assumes that incr > 0, which is NOT always the case
when doing bidirectional looping. I have yet to see a case
where both ofs <= ls AND incr < 0, however. */
i = (ls - ofs) / incr + 1;
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
}
/* Then do the bidirectional looping */
while(count)
{
/* Precalc how many times we should go through the loop */
i = ((incr > 0 ? le : ls) - ofs) / incr + 1;
if (i > count)
{
i = count;
count = 0;
}
else count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
if (ofs>=le)
{
/* fold the overshoot back in */
ofs = le2 - ofs;
incr *= -1;
}
else if (ofs <= ls)
{
ofs = ls2 - ofs;
incr *= -1;
}
}
#else /* PRECALC_LOOPS */
/* Play normally until inside the loop region */
if (ofs < ls)
{
while (count--)
{
RESAMPLATION;
ofs += incr;
if (ofs>=ls)
break;
}
}
/* Then do the bidirectional looping */
if (count>0)
while (count--)
{
RESAMPLATION;
ofs += incr;
if (ofs>=le)
{
/* fold the overshoot back in */
ofs = le - (ofs - le);
incr = -incr;
}
else if (ofs <= ls)
{
ofs = ls + (ls - ofs);
incr = -incr;
}
}
#endif /* PRECALC_LOOPS */
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
/*********************** vibrato versions ***************************/
/* We only need to compute one half of the vibrato sine cycle */
static int vib_phase_to_inc_ptr(int phase)
{
if (phase < VIBRATO_SAMPLE_INCREMENTS/2)
return VIBRATO_SAMPLE_INCREMENTS/2-1-phase;
else if (phase >= 3*VIBRATO_SAMPLE_INCREMENTS/2)
return 5*VIBRATO_SAMPLE_INCREMENTS/2-1-phase;
else
return phase-VIBRATO_SAMPLE_INCREMENTS/2;
}
static int32 update_vibrato(Voice *vp, int sign)
{
int32 depth;
int phase, pb;
double a;
if (vp->vibrato_phase++ >= 2*VIBRATO_SAMPLE_INCREMENTS-1)
vp->vibrato_phase=0;
phase=vib_phase_to_inc_ptr(vp->vibrato_phase);
if (vp->vibrato_sample_increment[phase])
{
if (sign)
return -vp->vibrato_sample_increment[phase];
else
return vp->vibrato_sample_increment[phase];
}
/* Need to compute this sample increment. */
depth=vp->sample->vibrato_depth<<7;
if (vp->vibrato_sweep)
{
/* Need to update sweep */
vp->vibrato_sweep_position += vp->vibrato_sweep;
if (vp->vibrato_sweep_position >= (1<vibrato_sweep=0;
else
{
/* Adjust depth */
depth *= vp->vibrato_sweep_position;
depth >>= SWEEP_SHIFT;
}
}
a = FSCALE(((double)(vp->sample->sample_rate) *
(double)(vp->frequency)) /
((double)(vp->sample->root_freq) *
(double)(play_mode->rate)),
FRACTION_BITS);
pb=(int)((sine(vp->vibrato_phase *
(SINE_CYCLE_LENGTH/(2*VIBRATO_SAMPLE_INCREMENTS)))
* (double)(depth) * VIBRATO_AMPLITUDE_TUNING));
if (pb<0)
{
pb=-pb;
a /= bend_fine[(pb>>5) & 0xFF] * bend_coarse[pb>>13];
}
else
a *= bend_fine[(pb>>5) & 0xFF] * bend_coarse[pb>>13];
/* If the sweep's over, we can store the newly computed sample_increment */
if (!vp->vibrato_sweep)
vp->vibrato_sample_increment[phase]=(int32) a;
if (sign)
a = -a; /* need to preserve the loop direction */
return (int32) a;
}
static sample_t *rs_vib_plain(int v, int32 *countptr)
{
/* Play sample until end, then free the voice. */
INTERPVARS;
Voice *vp=&voice[v];
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
int32
le=vp->sample->data_length,
ofs=vp->sample_offset,
incr=vp->sample_increment,
count=*countptr;
int
cc=vp->vibrato_control_counter;
/* This has never been tested */
if (incr<0) incr = -incr; /* In case we're coming out of a bidir loop */
while (count--)
{
if (!cc--)
{
cc=vp->vibrato_control_ratio;
incr=update_vibrato(vp, 0);
}
RESAMPLATION;
ofs += incr;
if (ofs >= le)
{
FINALINTERP;
vp->status=VOICE_FREE;
*countptr-=count+1;
break;
}
}
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
static sample_t *rs_vib_loop(Voice *vp, int32 count)
{
/* Play sample until end-of-loop, skip back and continue. */
INTERPVARS;
int32
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ll=le - vp->sample->loop_start;
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
int
cc=vp->vibrato_control_counter;
#ifdef PRECALC_LOOPS
int32 i;
int
vibflag=0;
while (count)
{
/* Hopefully the loop is longer than an increment */
while(ofs >= le)
ofs -= ll;
/* Precalc how many times to go through the loop, taking
the vibrato control ratio into account this time. */
i = (le - ofs) / incr + 1;
if(i > count) i = count;
if(i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
while(i--)
{
RESAMPLATION;
ofs += incr;
}
if(vibflag)
{
cc = vp->vibrato_control_ratio;
incr = update_vibrato(vp, 0);
vibflag = 0;
}
}
#else /* PRECALC_LOOPS */
while (count--)
{
if (!cc--)
{
cc=vp->vibrato_control_ratio;
incr=update_vibrato(vp, 0);
}
RESAMPLATION;
ofs += incr;
if (ofs>=le)
ofs -= ll; /* Hopefully the loop is longer than an increment. */
}
#endif /* PRECALC_LOOPS */
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
static sample_t *rs_vib_bidir(Voice *vp, int32 count)
{
INTERPVARS;
int32
ofs=vp->sample_offset,
incr=vp->sample_increment,
le=vp->sample->loop_end,
ls=vp->sample->loop_start;
sample_t
*dest=resample_buffer,
*src=vp->sample->data;
int
cc=vp->vibrato_control_counter;
#ifdef PRECALC_LOOPS
int32
le2=le<<1,
ls2=ls<<1,
i;
int
vibflag = 0;
/* Play normally until inside the loop region */
while (count && (ofs <= ls))
{
i = (ls - ofs) / incr + 1;
if (i > count) i = count;
if (i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
if (vibflag)
{
cc = vp->vibrato_control_ratio;
incr = update_vibrato(vp, 0);
vibflag = 0;
}
}
/* Then do the bidirectional looping */
while (count)
{
/* Precalc how many times we should go through the loop */
i = ((incr > 0 ? le : ls) - ofs) / incr + 1;
if(i > count) i = count;
if(i > cc)
{
i = cc;
vibflag = 1;
}
else cc -= i;
count -= i;
while (i--)
{
RESAMPLATION;
ofs += incr;
}
if (vibflag)
{
cc = vp->vibrato_control_ratio;
incr = update_vibrato(vp, (incr < 0));
vibflag = 0;
}
if (ofs >= le)
{
/* fold the overshoot back in */
ofs = le2 - ofs;
incr *= -1;
}
else if (ofs <= ls)
{
ofs = ls2 - ofs;
incr *= -1;
}
}
#else /* PRECALC_LOOPS */
/* Play normally until inside the loop region */
if (ofs < ls)
{
while (count--)
{
if (!cc--)
{
cc=vp->vibrato_control_ratio;
incr=update_vibrato(vp, 0);
}
RESAMPLATION;
ofs += incr;
if (ofs>=ls)
break;
}
}
/* Then do the bidirectional looping */
if (count>0)
while (count--)
{
if (!cc--)
{
cc=vp->vibrato_control_ratio;
incr=update_vibrato(vp, (incr < 0));
}
RESAMPLATION;
ofs += incr;
if (ofs>=le)
{
/* fold the overshoot back in */
ofs = le - (ofs - le);
incr = -incr;
}
else if (ofs <= ls)
{
ofs = ls + (ls - ofs);
incr = -incr;
}
}
#endif /* PRECALC_LOOPS */
vp->vibrato_control_counter=cc;
vp->sample_increment=incr;
vp->sample_offset=ofs; /* Update offset */
return resample_buffer;
}
sample_t *resample_voice(int v, int32 *countptr)
{
int32 ofs;
uint8 modes;
Voice *vp=&voice[v];
if (!(vp->sample->sample_rate))
{
/* Pre-resampled data -- just update the offset and check if
we're out of data. */
ofs=vp->sample_offset >> FRACTION_BITS; /* Kind of silly to use
FRACTION_BITS here... */
if (*countptr >= (vp->sample->data_length>>FRACTION_BITS) - ofs)
{
/* Note finished. Free the voice. */
vp->status = VOICE_FREE;
/* Let the caller know how much data we had left */
*countptr = (vp->sample->data_length>>FRACTION_BITS) - ofs;
}
else
vp->sample_offset += *countptr << FRACTION_BITS;
return vp->sample->data+ofs;
}
/* Need to resample. Use the proper function. */
modes=vp->sample->modes;
if (vp->vibrato_control_ratio)
{
if ((modes & MODES_LOOPING) &&
((modes & MODES_ENVELOPE) ||
(vp->status==VOICE_ON || vp->status==VOICE_SUSTAINED)))
{
if (modes & MODES_PINGPONG)
return rs_vib_bidir(vp, *countptr);
else
return rs_vib_loop(vp, *countptr);
}
else
return rs_vib_plain(v, countptr);
}
else
{
if ((modes & MODES_LOOPING) &&
((modes & MODES_ENVELOPE) ||
(vp->status==VOICE_ON || vp->status==VOICE_SUSTAINED)))
{
if (modes & MODES_PINGPONG)
return rs_bidir(vp, *countptr);
else
return rs_loop(vp, *countptr);
}
else
return rs_plain(v, countptr);
}
}
void pre_resample(Sample * sp)
{
double a, xdiff;
int32 incr, ofs, newlen, count;
int16 *newdata, *dest, *src = (int16 *) sp->data, *vptr;
int32 v, v1, v2, v3, v4, i;
static const char note_name[12][3] =
{
"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"
};
a = ((double) (sp->sample_rate) * freq_table[(int) (sp->note_to_use)]) /
((double) (sp->root_freq) * play_mode->rate);
if(sp->data_length / a >= 0x7fffffffL)
{
/* Too large to compute */
return;
}
newlen = (int32)(sp->data_length / a);
dest = newdata = safe_malloc((newlen >> (FRACTION_BITS - 1)) + 2);
count = (newlen >> FRACTION_BITS) - 1;
ofs = incr = (sp->data_length - (1 << FRACTION_BITS)) / count;
if (--count)
*dest++ = src[0];
/* Since we're pre-processing and this doesn't have to be done in
real-time, we go ahead and do the full sliding cubic interpolation. */
count--;
for(i = 0; i < count; i++)
{
vptr = src + (ofs >> FRACTION_BITS);
v1 = *(vptr - 1);
v2 = *vptr;
v3 = *(vptr + 1);
v4 = *(vptr + 2);
xdiff = FSCALENEG(ofs & FRACTION_MASK, FRACTION_BITS);
v = (int32)(v2 + (xdiff / 6.0) * (-2 * v1 - 3 * v2 + 6 * v3 - v4 +
xdiff * (3 * (v1 - 2 * v2 + v3) + xdiff * (-v1 + 3 * (v2 - v3) + v4))));
if(v < -32768)
*dest++ = -32768;
else if(v > 32767)
*dest++ = 32767;
else
*dest++ = (int16)v;
ofs += incr;
}
if (ofs & FRACTION_MASK)
{
v1 = src[ofs >> FRACTION_BITS];
v2 = src[(ofs >> FRACTION_BITS) + 1];
*dest++ = (int16)(v1 + (((v2 - v1) * (ofs & FRACTION_MASK)) >> FRACTION_BITS));
}
else
*dest++ = src[ofs >> FRACTION_BITS];
*dest = *(dest - 1) / 2;
*dest = *(dest - 1) / 2;
sp->data_length = newlen;
sp->loop_start = (int32)(sp->loop_start / a);
sp->loop_end = (int32)(sp->loop_end / a);
free(sp->data);
sp->data = (sample_t *) newdata;
sp->sample_rate = 0;
}