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/*
* Diverse Bristol audio routines.
* Copyright (c) by Nick Copeland <nickycopeland@hotmail.com> 1996,2012
*
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
/* This is sampler oscillator code. It is not used by any synth at the moment. */
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <math.h>
#include "bristol.h"
#include "sdco.h"
int
getHint(char *file)
{
char *index;
if ((index = rindex(file, '.')) != NULL)
{
index++;
if (strlen(index) <= 0)
return(HINT_RAW);
if (strcmp(index, "raw") == 0)
return(HINT_RAW);
}
return(HINT_UNKNOWN);
}
int
findKey(sampleData *sd, int key, int layer, int dir)
{
int ckey;
if (dir == RANGE_UP)
{
/*
* If we are outside of our range, return.
*/
if (key == 127)
return(-1);
for (ckey = key + 1; ckey < 128; ckey++)
{
if (sd[ckey].layer[layer].wave == 0)
continue;
return(ckey);
}
} else {
/*
* If we are outside of our range, return.
*/
if (key == 0)
return(-1);
for (ckey = key - 1; ckey < 128; ckey--)
{
if (sd[ckey].layer[layer].wave == 0)
continue;
return(ckey);
}
}
return(-1);
}
/*
* This is called after the sampleData structure has been filled with as many
* samples as as specified for the voice, and will fill in any pointers for
* data that needs to be interpolated between keys.
*
* Two potential methods for filling the structures. Firstly, take nearest
* available wave, secondly take a mixture of the nearest below and nearest
* above. The former will be better for the Rhodes since it only has a single
* tine, and needs a purer sound. The latter would be useful for a piano,
* as it has multiple strings per note, and we can do multiple crosspoints
* where the nearest piano and nearest forte are not always the same sample.
*/
int
fixWavepointers(sampleData *sd, int layer)
{
int ckey;
for (ckey = 0; ckey < 128; ckey++)
{
/*
* See if we have a piano wave, if not, find the upper and lower
* pairs.
*/
if (sd[ckey].layer[layer].wave == 0)
{
int lower, upper, target;
double freqstep;
/*
* We do not have a wave on this note. Go and find some upper and
* lower reference pairs, and use the nearest of them.
*/
lower = findKey(sd, ckey, layer, RANGE_DOWN);
upper = findKey(sd, ckey, layer, RANGE_UP);
/*
* If we have no samples on this layer, return.
*/
if ((lower == -1) && (upper == -1))
return(-1);
if (lower == -1)
{
target = upper;
} else {
if (upper == -1)
target = lower;
else {
/*
* If we have a contention between samples, find nearest.
*/
if ((ckey - lower) < (upper - ckey))
target = lower;
else
target = upper;
}
}
sd[ckey].layer[layer].refwave = target;
/*
* Since we do not have a wave loaded on this note we need to
* evaluate the rate at which the related sample should be
* played. This is 2s power twelth of the distance between the
* notes.
*/
freqstep = ckey - target;
if (freqstep > 0)
sd[ckey].layer[layer].sr = pow(2, freqstep / 12);
else
sd[ckey].layer[layer].sr = pow(2, freqstep / 12);
} else {
/*
* We have a wave on this note. Take this index, and unity gain.
*/
sd[ckey].layer[layer].refwave = ckey;
/*
* If we have the wave then the step rate is 1.0
*/
sd[ckey].layer[layer].sr = 1.0;
}
/*
printf("k %i-%i: w %08x %i %i %i %i %i %i %f %i\n",
layer, ckey,
sd[ckey].layer[layer].wave,
sd[ckey].layer[layer].nsr,
sd[ckey].layer[layer].count,
sd[ckey].layer[layer].lnr,
sd[ckey].layer[layer].lfr,
sd[ckey].layer[layer].lt,
sd[ckey].layer[layer].refwave,
sd[ckey].layer[layer].sr,
sd[ckey].layer[layer].fade);
*/
}
return(0);
}
int
convertRhodes(sampleData *sd, char *file, int loc, int layer)
{
int fd;
short *src;
float *dst;
struct stat sbuf;
if (sd[loc].layer[layer].wave != 0)
bristolfree(sd[loc].layer[layer].wave);
if ((fd = open(file, O_RDONLY)) < 0)
return(-1);
if (fstat(fd, &sbuf) < 0)
{
printf("Could not stat file\n");
close(fd);
} else
printf("filesize is %i bytes\n", (int) sbuf.st_size);
sd[loc].layer[layer].wave
= (float *) bristolmalloc((sbuf.st_size / 2) * sizeof(float));
sd[loc].layer[layer].count = sbuf.st_size / 2;
sd[loc].layer[layer].lnr = 0;
sd[loc].layer[layer].lfr = sbuf.st_size / 2;
sd[loc].layer[layer].lt = LOOP_NONE;
if (read(fd, sd[loc].layer[layer].wave, sbuf.st_size) != sbuf.st_size)
{
bristolfree(sd[loc].layer[layer].wave);
close(fd);
return(-1);
}
/*
* Get our pointers to refer to end of samples.
*/
src = ((short *) sd[loc].layer[layer].wave) + (sbuf.st_size / 2);
dst = sd[loc].layer[layer].wave + (sbuf.st_size / 2);
/*
printf("buffer %x, src %x, dst %x\n", sd[loc].layer[layer].wave, src, dst);
* Then converge the samples into float from back to front.
*/
for (; src != (short *) sd[loc].layer[layer].wave;)
*--dst = ((float) *--src) * 0.003;
sd[loc].layer[layer].nsr = 44100; /* must go when sampler is released */
close(fd);
/*
* Fix some table pointers for layer 0 and 1
*/
fixWavepointers(sd, layer);
return(0);
}
int
freeWavemem(sampleData *sd)
{
printf("Need to clean up the free() wave memory code\n");
return(0);
}
int
convertWave(sampleData *sd, char *file, int type, int loc, int layer)
{
int spec;
/*
* We have been passed a sampledata array, a filename, and at least some
* conversion and index hints. We may not use the latter two.
* Minimally we open the file and load its data into the hinted location.
*/
/*
* See if the filename gives any indication of type, or if the first few
* bytes do.
*/
if ((spec = getHint(file)) != type)
printf("file %s does not indicate specified type: %i, %i\n",
file, spec, type);
if (spec == HINT_UNKNOWN)
spec = type;
if (type == HINT_RHODES)
{
/*
* This is a predefined set of samples
*/
return(convertRhodes(sd, file, loc, layer));
}
switch(spec) {
case HINT_RAW:
/*
* Raw file. Load its contents into the specified location and
* configure a set of defaults for the rest of the table.
*/
break;
default:
break;
}
return(-1);
}
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