Linux Kernel  3.7.1
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gus_volume.c
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1 /*
2  * Copyright (c) by Jaroslav Kysela <[email protected]>
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 */