mirrors/alsa-lib
1
0
Fork 0
mirror of https://github.com/alsa-project/alsa-lib.git synced 2025-11-03 09:01:52 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fix wrong scales in linear volume calculation

Browse source 
Fixed wrong scales of dB values (TLV is 0.01dB unit) in the linear
volume calculation.
This commit is contained in:
Takashi Iwai 2006-09-07 20:51:41 +02:00
parent 70825bb7e6
commit 9d2518bb91
1 changed files with 5 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

10
src/mixer/simple_none.c
View file

@ -1091,8 +1091,8 @@ static int do_convert_to_dB(unsigned int *tlv, long rangemin, long rangemax,
maxdb;
else {
/* FIXME: precalculate and cache these values */
double lmin = pow(10.0, mindb/20.0);
double lmax = pow(10.0, maxdb/20.0);
double lmin = pow(10.0, mindb/2000.0);
double lmax = pow(10.0, maxdb/2000.0);
val = (lmax - lmin) * val + lmin;
*db_gain = (long)(100.0 * 20.0 * log10(val));
}
@ -1293,9 +1293,9 @@ static int do_convert_from_dB(unsigned int *tlv, long rangemin, long rangemax,
/* FIXME: precalculate and cache vmin and vmax */
double vmin, vmax, v;
vmin = (min <= SND_CTL_TLV_DB_GAIN_MUTE) ? 0.0 :
pow(10.0, (double)min / 20.0);
vmax = !max ? 1.0 : pow(10.0, (double)max / 20.0);
v = pow(10.0, (double)db_gain / 20.0);
pow(10.0, (double)min / 2000.0);
vmax = !max ? 1.0 : pow(10.0, (double)max / 2000.0);
v = pow(10.0, (double)db_gain / 2000.0);
v = (v - vmin) * (rangemax - rangemin) / (vmax - vmin);
if (xdir > 0)
v = ceil(v);