mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 13:13:57 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
154 lines
3.3 KiB
C
154 lines
3.3 KiB
C
|
|
/*
|
|
* gus_vol.c - Compute volume for GUS.
|
|
*
|
|
*
|
|
* Copyright (C) by Hannu Savolainen 1993-1997
|
|
*
|
|
* OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
|
|
* Version 2 (June 1991). See the "COPYING" file distributed with this software
|
|
* for more info.
|
|
*/
|
|
#include "sound_config.h"
|
|
|
|
#include "gus.h"
|
|
#include "gus_linearvol.h"
|
|
|
|
#define GUS_VOLUME gus_wave_volume
|
|
|
|
|
|
extern int gus_wave_volume;
|
|
|
|
/*
|
|
* Calculate gus volume from note velocity, main volume, expression, and
|
|
* intrinsic patch volume given in patch library. Expression is multiplied
|
|
* in, so it emphasizes differences in note velocity, while main volume is
|
|
* added in -- I don't know whether this is right, but it seems reasonable to
|
|
* me. (In the previous stage, main volume controller messages were changed
|
|
* to expression controller messages, if they were found to be used for
|
|
* dynamic volume adjustments, so here, main volume can be assumed to be
|
|
* constant throughout a song.)
|
|
*
|
|
* Intrinsic patch volume is added in, but if over 64 is also multiplied in, so
|
|
* we can give a big boost to very weak voices like nylon guitar and the
|
|
* basses. The normal value is 64. Strings are assigned lower values.
|
|
*/
|
|
|
|
unsigned short gus_adagio_vol(int vel, int mainv, int xpn, int voicev)
|
|
{
|
|
int i, m, n, x;
|
|
|
|
|
|
/*
|
|
* A voice volume of 64 is considered neutral, so adjust the main volume if
|
|
* something other than this neutral value was assigned in the patch
|
|
* library.
|
|
*/
|
|
x = 256 + 6 * (voicev - 64);
|
|
|
|
/*
|
|
* Boost expression by voice volume above neutral.
|
|
*/
|
|
|
|
if (voicev > 65)
|
|
xpn += voicev - 64;
|
|
xpn += (voicev - 64) / 2;
|
|
|
|
/*
|
|
* Combine multiplicative and level components.
|
|
*/
|
|
x = vel * xpn * 6 + (voicev / 4) * x;
|
|
|
|
#ifdef GUS_VOLUME
|
|
/*
|
|
* Further adjustment by installation-specific master volume control
|
|
* (default 60).
|
|
*/
|
|
x = (x * GUS_VOLUME * GUS_VOLUME) / 10000;
|
|
#endif
|
|
|
|
#ifdef GUS_USE_CHN_MAIN_VOLUME
|
|
/*
|
|
* Experimental support for the channel main volume
|
|
*/
|
|
|
|
mainv = (mainv / 2) + 64; /* Scale to 64 to 127 */
|
|
x = (x * mainv * mainv) / 16384;
|
|
#endif
|
|
|
|
if (x < 2)
|
|
return (0);
|
|
else if (x >= 65535)
|
|
return ((15 << 8) | 255);
|
|
|
|
/*
|
|
* Convert to GUS's logarithmic form with 4 bit exponent i and 8 bit
|
|
* mantissa m.
|
|
*/
|
|
|
|
n = x;
|
|
i = 7;
|
|
if (n < 128)
|
|
{
|
|
while (i > 0 && n < (1 << i))
|
|
i--;
|
|
}
|
|
else
|
|
{
|
|
while (n > 255)
|
|
{
|
|
n >>= 1;
|
|
i++;
|
|
}
|
|
}
|
|
/*
|
|
* Mantissa is part of linear volume not expressed in exponent. (This is
|
|
* not quite like real logs -- I wonder if it's right.)
|
|
*/
|
|
m = x - (1 << i);
|
|
|
|
/*
|
|
* Adjust mantissa to 8 bits.
|
|
*/
|
|
if (m > 0)
|
|
{
|
|
if (i > 8)
|
|
m >>= i - 8;
|
|
else if (i < 8)
|
|
m <<= 8 - i;
|
|
}
|
|
return ((i << 8) + m);
|
|
}
|
|
|
|
/*
|
|
* Volume-values are interpreted as linear values. Volume is based on the
|
|
* value supplied with SEQ_START_NOTE(), channel main volume (if compiled in)
|
|
* and the volume set by the mixer-device (default 60%).
|
|
*/
|
|
|
|
unsigned short gus_linear_vol(int vol, int mainvol)
|
|
{
|
|
int mixer_mainvol;
|
|
|
|
if (vol <= 0)
|
|
vol = 0;
|
|
else if (vol >= 127)
|
|
vol = 127;
|
|
|
|
#ifdef GUS_VOLUME
|
|
mixer_mainvol = GUS_VOLUME;
|
|
#else
|
|
mixer_mainvol = 100;
|
|
#endif
|
|
|
|
#ifdef GUS_USE_CHN_MAIN_VOLUME
|
|
if (mainvol <= 0)
|
|
mainvol = 0;
|
|
else if (mainvol >= 127)
|
|
mainvol = 127;
|
|
#else
|
|
mainvol = 127;
|
|
#endif
|
|
return gus_linearvol[(((vol * mainvol) / 127) * mixer_mainvol) / 100];
|
|
}
|