sound/isa/gus/gus_volume.c

   1 /*
   2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   3  *
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  *
  19  */
  20
  21 #include <linux/time.h>
  22 #include <sound/core.h>
  23 #include <sound/gus.h>
  24 #define __GUS_TABLES_ALLOC__
  25 #include "gus_tables.h"
  26
  27 EXPORT_SYMBOL(snd_gf1_atten_table); /* for snd-gus-synth module */
  28
  29 unsigned short snd_gf1_lvol_to_gvol_raw(unsigned int vol)
  30 {
  31         unsigned short e, m, tmp;
  32
  33         if (vol > 65535)
  34                 vol = 65535;
  35         tmp = vol;
  36         e = 7;
  37         if (tmp < 128) {
  38                 while (e > 0 && tmp < (1 << e))
  39                         e--;
  40         } else {
  41                 while (tmp > 255) {
  42                         tmp >>= 1;
  43                         e++;
  44                 }
  45         }
  46         m = vol - (1 << e);
  47         if (m > 0) {
  48                 if (e > 8)
  49                         m >>= e - 8;
  50                 else if (e < 8)
  51                         m <<= 8 - e;
  52                 m &= 255;
  53         }
  54         return (e << 8) | m;
  55 }
  56
  57 #if 0
  58
  59 unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
  60 {
  61         unsigned int rvol;
  62         unsigned short e, m;
  63
  64         if (!gf1_vol)
  65                 return 0;
  66         e = gf1_vol >> 8;
  67         m = (unsigned char) gf1_vol;
  68         rvol = 1 << e;
  69         if (e > 8)
  70                 return rvol | (m << (e - 8));
  71         return rvol | (m >> (8 - e));
  72 }
  73
  74 unsigned int snd_gf1_calc_ramp_rate(struct snd_gus_card * gus,
  75                                     unsigned short start,
  76                                     unsigned short end,
  77                                     unsigned int us)
  78 {
  79         static unsigned char vol_rates[19] =
  80         {
  81                 23, 24, 26, 28, 29, 31, 32, 34,
  82                 36, 37, 39, 40, 42, 44, 45, 47,
  83                 49, 50, 52
  84         };
  85         unsigned short range, increment, value, i;
  86
  87         start >>= 4;
  88         end >>= 4;
  89         if (start < end)
  90                 us /= end - start;
  91         else
  92                 us /= start - end;
  93         range = 4;
  94         value = gus->gf1.enh_mode ?
  95             vol_rates[0] :
  96             vol_rates[gus->gf1.active_voices - 14];
  97         for (i = 0; i < 3; i++) {
  98                 if (us < value) {
  99                         range = i;
 100                         break;
 101                 } else
 102                         value <<= 3;
 103         }
 104         if (range == 4) {
 105                 range = 3;
 106                 increment = 1;
 107         } else
 108                 increment = (value + (value >> 1)) / us;
 109         return (range << 6) | (increment & 0x3f);
 110 }
 111
 112 #endif  /*  0  */
 113
 114 unsigned short snd_gf1_translate_freq(struct snd_gus_card * gus, unsigned int freq16)
 115 {
 116         freq16 >>= 3;
 117         if (freq16 < 50)
 118                 freq16 = 50;
 119         if (freq16 & 0xf8000000) {
 120                 freq16 = ~0xf8000000;
 121                 snd_printk(KERN_ERR "snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
 122         }
 123         return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
 124 }
 125
 126 #if 0
 127
 128 short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
 129 {
 130         static short vibrato_table[] =
 131         {
 132                 0, 0, 32, 592, 61, 1175, 93, 1808,
 133                 124, 2433, 152, 3007, 182, 3632, 213, 4290,
 134                 241, 4834, 255, 5200
 135         };
 136
 137         long depth;
 138         short *vi1, *vi2, pcents, v1;
 139
 140         pcents = cents < 0 ? -cents : cents;
 141         for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
 142         v1 = *(vi1 + 1);
 143         /* The FC table above is a list of pairs. The first number in the pair     */
 144         /* is the cents index from 0-255 cents, and the second number in the       */
 145         /* pair is the FC adjustment needed to change the pitch by the indexed     */
 146         /* number of cents. The table was created for an FC of 32768.              */
 147         /* The following expression does a linear interpolation against the        */
 148         /* approximated log curve in the table above, and then scales the number   */
 149         /* by the FC before the LFO. This calculation also adjusts the output      */
 150         /* value to produce the appropriate depth for the hardware. The depth      */
 151         /* is 2 * desired FC + 1.                                                  */
 152         depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
 153         if (depth)
 154                 depth++;
 155         if (depth > 255)
 156                 depth = 255;
 157         return cents < 0 ? -(short) depth : (short) depth;
 158 }
 159
 160 unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
 161 {
 162         static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
 163         int wheel, sensitivity;
 164         unsigned int mantissa, f1, f2;
 165         unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
 166         char bend_down = 0;
 167         int bend;
 168
 169         if (!sens)
 170                 return 1024;
 171         wheel = (int) pitchbend - 8192;
 172         sensitivity = ((int) sens * wheel) / 128;
 173         if (sensitivity < 0) {
 174                 bend_down = 1;
 175                 sensitivity = -sensitivity;
 176         }
 177         semitones = (unsigned int) (sensitivity >> 13);
 178         mantissa = sensitivity % 8192;
 179         f1_index = semitones % 12;
 180         f2_index = (semitones + 1) % 12;
 181         f1_power = semitones / 12;
 182         f2_power = (semitones + 1) / 12;
 183         f1 = log_table[f1_index] << f1_power;
 184         f2 = log_table[f2_index] << f2_power;
 185         bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
 186         if (bend_down)
 187                 bend = 1048576L / bend;
 188         return bend;
 189 }
 190
 191 unsigned short snd_gf1_compute_freq(unsigned int freq,
 192                                     unsigned int rate,
 193                                     unsigned short mix_rate)
 194 {
 195         unsigned int fc;
 196         int scale = 0;
 197
 198         while (freq >= 4194304L) {
 199                 scale++;
 200                 freq >>= 1;
 201         }
 202         fc = (freq << 10) / rate;
 203         if (fc > 97391L) {
 204                 fc = 97391;
 205                 snd_printk(KERN_ERR "patch: (1) fc frequency overflow - %u\n", fc);
 206         }
 207         fc = (fc * 44100UL) / mix_rate;
 208         while (scale--)
 209                 fc <<= 1;
 210         if (fc > 65535L) {
 211                 fc = 65535;
 212                 snd_printk(KERN_ERR "patch: (2) fc frequency overflow - %u\n", fc);
 213         }
 214         return (unsigned short) fc;
 215 }
 216
 217 #endif  /*  0  */