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DEFINITIONS
This source file includes following definitions.
- snd_gf1_lvol_to_gvol_raw
- snd_gf1_gvol_to_lvol_raw
- snd_gf1_calc_ramp_rate
- snd_gf1_translate_freq
- snd_gf1_compute_vibrato
- snd_gf1_compute_pitchbend
- snd_gf1_compute_freq
/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*
*
* 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
*
*/
#include <linux/time.h>
#include <sound/core.h>
#include <sound/gus.h>
#define __GUS_TABLES_ALLOC__
#include "gus_tables.h"
EXPORT_SYMBOL(snd_gf1_atten_table); /* for snd-gus-synth module */
unsigned short snd_gf1_lvol_to_gvol_raw(unsigned int vol)
{
unsigned short e, m, tmp;
if (vol > 65535)
vol = 65535;
tmp = vol;
e = 7;
if (tmp < 128) {
while (e > 0 && tmp < (1 << e))
e--;
} else {
while (tmp > 255) {
tmp >>= 1;
e++;
}
}
m = vol - (1 << e);
if (m > 0) {
if (e > 8)
m >>= e - 8;
else if (e < 8)
m <<= 8 - e;
m &= 255;
}
return (e << 8) | m;
}
#if 0
unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
{
unsigned int rvol;
unsigned short e, m;
if (!gf1_vol)
return 0;
e = gf1_vol >> 8;
m = (unsigned char) gf1_vol;
rvol = 1 << e;
if (e > 8)
return rvol | (m << (e - 8));
return rvol | (m >> (8 - e));
}
unsigned int snd_gf1_calc_ramp_rate(struct snd_gus_card * gus,
unsigned short start,
unsigned short end,
unsigned int us)
{
static unsigned char vol_rates[19] =
{
23, 24, 26, 28, 29, 31, 32, 34,
36, 37, 39, 40, 42, 44, 45, 47,
49, 50, 52
};
unsigned short range, increment, value, i;
start >>= 4;
end >>= 4;
if (start < end)
us /= end - start;
else
us /= start - end;
range = 4;
value = gus->gf1.enh_mode ?
vol_rates[0] :
vol_rates[gus->gf1.active_voices - 14];
for (i = 0; i < 3; i++) {
if (us < value) {
range = i;
break;
} else
value <<= 3;
}
if (range == 4) {
range = 3;
increment = 1;
} else
increment = (value + (value >> 1)) / us;
return (range << 6) | (increment & 0x3f);
}
#endif /* 0 */
unsigned short snd_gf1_translate_freq(struct snd_gus_card * gus, unsigned int freq16)
{
freq16 >>= 3;
if (freq16 < 50)
freq16 = 50;
if (freq16 & 0xf8000000) {
freq16 = ~0xf8000000;
snd_printk(KERN_ERR "snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
}
return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
}
#if 0
short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
{
static short vibrato_table[] =
{
0, 0, 32, 592, 61, 1175, 93, 1808,
124, 2433, 152, 3007, 182, 3632, 213, 4290,
241, 4834, 255, 5200
};
long depth;
short *vi1, *vi2, pcents, v1;
pcents = cents < 0 ? -cents : cents;
for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
v1 = *(vi1 + 1);
/* The FC table above is a list of pairs. The first number in the pair */
/* is the cents index from 0-255 cents, and the second number in the */
/* pair is the FC adjustment needed to change the pitch by the indexed */
/* number of cents. The table was created for an FC of 32768. */
/* The following expression does a linear interpolation against the */
/* approximated log curve in the table above, and then scales the number */
/* by the FC before the LFO. This calculation also adjusts the output */
/* value to produce the appropriate depth for the hardware. The depth */
/* is 2 * desired FC + 1. */
depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
if (depth)
depth++;
if (depth > 255)
depth = 255;
return cents < 0 ? -(short) depth : (short) depth;
}
unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
{
static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
int wheel, sensitivity;
unsigned int mantissa, f1, f2;
unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
char bend_down = 0;
int bend;
if (!sens)
return 1024;
wheel = (int) pitchbend - 8192;
sensitivity = ((int) sens * wheel) / 128;
if (sensitivity < 0) {
bend_down = 1;
sensitivity = -sensitivity;
}
semitones = (unsigned int) (sensitivity >> 13);
mantissa = sensitivity % 8192;
f1_index = semitones % 12;
f2_index = (semitones + 1) % 12;
f1_power = semitones / 12;
f2_power = (semitones + 1) / 12;
f1 = log_table[f1_index] << f1_power;
f2 = log_table[f2_index] << f2_power;
bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
if (bend_down)
bend = 1048576L / bend;
return bend;
}
unsigned short snd_gf1_compute_freq(unsigned int freq,
unsigned int rate,
unsigned short mix_rate)
{
unsigned int fc;
int scale = 0;
while (freq >= 4194304L) {
scale++;
freq >>= 1;
}
fc = (freq << 10) / rate;
if (fc > 97391L) {
fc = 97391;
snd_printk(KERN_ERR "patch: (1) fc frequency overflow - %u\n", fc);
}
fc = (fc * 44100UL) / mix_rate;
while (scale--)
fc <<= 1;
if (fc > 65535L) {
fc = 65535;
snd_printk(KERN_ERR "patch: (2) fc frequency overflow - %u\n", fc);
}
return (unsigned short) fc;
}
#endif /* 0 */