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Add volume control like it is done for MP3 to the 16 bit 'mixers' (ie

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using a 32 level only volume range).

svn-id: r4365
This commit is contained in:
Lionel Ulmer 2002-05-20 20:35:25 +00:00
parent 1db4ae7c2f
commit f6b934e068
1 changed files with 7 additions and 6 deletions
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13
sound/mixer.cpp
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@ -264,12 +264,13 @@ static void mix_unsigned_stereo_8(int16 *data, uint len, byte **s_ptr, uint32 *f
}
static void mix_signed_mono_16(int16 *data, uint len, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab) {
uint32 fp_pos = *fp_pos_ptr;
unsigned char volume = ((int) vol_tab[1]) * 32 / 255;
byte *s = *s_ptr;
do {
int16 sample = (int16) (((int32) ((*s << 8) | *(s + 1))) * volume / 32);
fp_pos += fp_speed;
// FIXME: missing volume table
*data++ += ((*s << 8) | *(s + 1));
*data++ += ((*s << 8) | *(s + 1));
*data++ += sample;
*data++ += sample;
s += (fp_pos >> 16) << 1;
fp_pos &= 0x0000FFFF;
} while (--len);
@ -282,12 +283,12 @@ static void mix_unsigned_mono_16(int16 *data, uint len, byte **s_ptr, uint32 *fp
}
static void mix_signed_stereo_16(int16 *data, uint len, byte **s_ptr, uint32 *fp_pos_ptr, int fp_speed, const int16 *vol_tab) {
uint32 fp_pos = *fp_pos_ptr;
unsigned char volume = ((int) vol_tab[1]) * 32 / 255;
byte *s = *s_ptr;
do {
fp_pos += fp_speed;
// FIXME: missing volume table
*data++ += ((*s << 8) | *(s + 1));
*data++ += ((*(s + 2) << 8) | *(s + 3));
*data++ += (int16) ((((int32) ((*(s ) << 8) | *(s + 1))) * volume) / 32);
*data++ += (int16) ((((int32) ((*(s + 2) << 8) | *(s + 3))) * volume) / 32);
s += (fp_pos >> 16) << 2;
fp_pos &= 0x0000FFFF;
} while (--len);