diff options
Diffstat (limited to 'sound/isa/gus/gus_volume.c')
| -rw-r--r-- | sound/isa/gus/gus_volume.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/sound/isa/gus/gus_volume.c b/sound/isa/gus/gus_volume.c new file mode 100644 index 00000000..3dd841ae --- /dev/null +++ b/sound/isa/gus/gus_volume.c @@ -0,0 +1,218 @@ +/* + * 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 <linux/export.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 */ |