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 <linux/export.h>
  23 #include <sound/core.h>
  24 #include <sound/gus.h>
  25 #define __GUS_TABLES_ALLOC__
  26 #include "gus_tables.h"
  27
  28 EXPORT_SYMBOL(snd_gf1_atten_table); /* for snd-gus-synth module */
  29
  30 unsigned short snd_gf1_lvol_to_gvol_raw(unsigned int vol)
  31 {
  32         unsigned short e, m, tmp;
  33
  34         if (vol > 65535)
  35                 vol = 65535;
  36         tmp = vol;
  37         e = 7;
  38         if (tmp < 128) {
  39                 while (e > 0 && tmp < (1 << e))
  40                         e--;
  41         } else {
  42                 while (tmp > 255) {
  43                         tmp >>= 1;
  44                         e++;
  45                 }
  46         }
  47         m = vol - (1 << e);
  48         if (m > 0) {
  49                 if (e > 8)
  50                         m >>= e - 8;
  51                 else if (e < 8)
  52                         m <<= 8 - e;
  53                 m &= 255;
  54         }
  55         return (e << 8) | m;
  56 }
  57
  58 #if 0
  59
  60 unsigned int snd_gf1_gvol_to_lvol_raw(unsigned short gf1_vol)
  61 {
  62         unsigned int rvol;
  63         unsigned short e, m;
  64
  65         if (!gf1_vol)
  66                 return 0;
  67         e = gf1_vol >> 8;
  68         m = (unsigned char) gf1_vol;
  69         rvol = 1 << e;
  70         if (e > 8)
  71                 return rvol | (m << (e - 8));
  72         return rvol | (m >> (8 - e));
  73 }
  74
  75 unsigned int snd_gf1_calc_ramp_rate(struct snd_gus_card * gus,
  76                                     unsigned short start,
  77                                     unsigned short end,
  78                                     unsigned int us)
  79 {
  80         static unsigned char vol_rates[19] =
  81         {
  82                 23, 24, 26, 28, 29, 31, 32, 34,
  83                 36, 37, 39, 40, 42, 44, 45, 47,
  84                 49, 50, 52
  85         };
  86         unsigned short range, increment, value, i;
  87
  88         start >>= 4;
  89         end >>= 4;
  90         if (start < end)
  91                 us /= end - start;
  92         else
  93                 us /= start - end;
  94         range = 4;
  95         value = gus->gf1.enh_mode ?
  96             vol_rates[0] :
  97             vol_rates[gus->gf1.active_voices - 14];
  98         for (i = 0; i < 3; i++) {
  99                 if (us < value) {
 100                         range = i;
 101                         break;
 102                 } else
 103                         value <<= 3;
 104         }
 105         if (range == 4) {
 106                 range = 3;
 107                 increment = 1;
 108         } else
 109                 increment = (value + (value >> 1)) / us;
 110         return (range << 6) | (increment & 0x3f);
 111 }
 112
 113 #endif  /*  0  */
 114
 115 unsigned short snd_gf1_translate_freq(struct snd_gus_card * gus, unsigned int freq16)
 116 {
 117         freq16 >>= 3;
 118         if (freq16 < 50)
 119                 freq16 = 50;
 120         if (freq16 & 0xf8000000) {
 121                 freq16 = ~0xf8000000;
 122                 snd_printk(KERN_ERR "snd_gf1_translate_freq: overflow - freq = 0x%x\n", freq16);
 123         }
 124         return ((freq16 << 9) + (gus->gf1.playback_freq >> 1)) / gus->gf1.playback_freq;
 125 }
 126
 127 #if 0
 128
 129 short snd_gf1_compute_vibrato(short cents, unsigned short fc_register)
 130 {
 131         static short vibrato_table[] =
 132         {
 133                 0, 0, 32, 592, 61, 1175, 93, 1808,
 134                 124, 2433, 152, 3007, 182, 3632, 213, 4290,
 135                 241, 4834, 255, 5200
 136         };
 137
 138         long depth;
 139         short *vi1, *vi2, pcents, v1;
 140
 141         pcents = cents < 0 ? -cents : cents;
 142         for (vi1 = vibrato_table, vi2 = vi1 + 2; pcents > *vi2; vi1 = vi2, vi2 += 2);
 143         v1 = *(vi1 + 1);
 144         /* The FC table above is a list of pairs. The first number in the pair     */
 145         /* is the cents index from 0-255 cents, and the second number in the       */
 146         /* pair is the FC adjustment needed to change the pitch by the indexed     */
 147         /* number of cents. The table was created for an FC of 32768.              */
 148         /* The following expression does a linear interpolation against the        */
 149         /* approximated log curve in the table above, and then scales the number   */
 150         /* by the FC before the LFO. This calculation also adjusts the output      */
 151         /* value to produce the appropriate depth for the hardware. The depth      */
 152         /* is 2 * desired FC + 1.                                                  */
 153         depth = (((int) (*(vi2 + 1) - *vi1) * (pcents - *vi1) / (*vi2 - *vi1)) + v1) * fc_register >> 14;
 154         if (depth)
 155                 depth++;
 156         if (depth > 255)
 157                 depth = 255;
 158         return cents < 0 ? -(short) depth : (short) depth;
 159 }
 160
 161 unsigned short snd_gf1_compute_pitchbend(unsigned short pitchbend, unsigned short sens)
 162 {
 163         static long log_table[] = {1024, 1085, 1149, 1218, 1290, 1367, 1448, 1534, 1625, 1722, 1825, 1933};
 164         int wheel, sensitivity;
 165         unsigned int mantissa, f1, f2;
 166         unsigned short semitones, f1_index, f2_index, f1_power, f2_power;
 167         char bend_down = 0;
 168         int bend;
 169
 170         if (!sens)
 171                 return 1024;
 172         wheel = (int) pitchbend - 8192;
 173         sensitivity = ((int) sens * wheel) / 128;
 174         if (sensitivity < 0) {
 175                 bend_down = 1;
 176                 sensitivity = -sensitivity;
 177         }
 178         semitones = (unsigned int) (sensitivity >> 13);
 179         mantissa = sensitivity % 8192;
 180         f1_index = semitones % 12;
 181         f2_index = (semitones + 1) % 12;
 182         f1_power = semitones / 12;
 183         f2_power = (semitones + 1) / 12;
 184         f1 = log_table[f1_index] << f1_power;
 185         f2 = log_table[f2_index] << f2_power;
 186         bend = (int) ((((f2 - f1) * mantissa) >> 13) + f1);
 187         if (bend_down)
 188                 bend = 1048576L / bend;
 189         return bend;
 190 }
 191
 192 unsigned short snd_gf1_compute_freq(unsigned int freq,
 193                                     unsigned int rate,
 194                                     unsigned short mix_rate)
 195 {
 196         unsigned int fc;
 197         int scale = 0;
 198
 199         while (freq >= 4194304L) {
 200                 scale++;
 201                 freq >>= 1;
 202         }
 203         fc = (freq << 10) / rate;
 204         if (fc > 97391L) {
 205                 fc = 97391;
 206                 snd_printk(KERN_ERR "patch: (1) fc frequency overflow - %u\n", fc);
 207         }
 208         fc = (fc * 44100UL) / mix_rate;
 209         while (scale--)
 210                 fc <<= 1;
 211         if (fc > 65535L) {
 212                 fc = 65535;
 213                 snd_printk(KERN_ERR "patch: (2) fc frequency overflow - %u\n", fc);
 214         }
 215         return (unsigned short) fc;
 216 }
 217
 218 #endif  /*  0  */