Added soft clipping for software volume control

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@5064 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
anders 2002-03-13 12:32:42 +00:00
parent 54610a5997
commit ead9372b40
3 changed files with 50 additions and 14 deletions

View File

@ -112,6 +112,7 @@ struct config ao_plugin_conf[]={
{"fout", &ao_plugin_cfg.pl_resample_fout, CONF_TYPE_INT, CONF_MIN, 0, 0, NULL},
{"volume", &ao_plugin_cfg.pl_volume_volume, CONF_TYPE_INT, CONF_RANGE, 0, 255, NULL},
{"mul", &ao_plugin_cfg.pl_extrastereo_mul, CONF_TYPE_FLOAT, CONF_MIN, 0, 0, NULL},
{"softclip", &ao_plugin_cfg.pl_volume_softclip, CONF_TYPE_FLAG, 0, 0, 1, NULL},
{NULL, NULL, 0, 0, 0, 0, NULL}
};

View File

@ -37,6 +37,7 @@ typedef struct ao_plugin_cfg_s
int pl_resample_fout; // Output frequency from resampling
int pl_volume_volume; // Initial volume setting
float pl_extrastereo_mul; // Stereo enhancer multiplier
int pl_volume_softclip; // Enable soft clipping
} ao_plugin_cfg_t;
extern ao_plugin_cfg_t ao_plugin_cfg;
@ -47,8 +48,9 @@ extern ao_plugin_cfg_t ao_plugin_cfg;
AFMT_S16_LE, \
0, \
48000, \
255, \
2.5 \
101, \
2.5, \
0 \
};
// This block should not be available in the pl_xxxx files

View File

@ -4,6 +4,14 @@
#define PLUGIN
// Some limits
#define MIN_S16 -32650
#define MAX_S16 32650
#define MIN_U8 0
#define MAX_U8 255
#define MIN_S8 -128
#define MAX_S8 127
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
@ -87,7 +95,7 @@ static int init(){
of wether this plugin is in use or not. */
pl_volume.inuse=1;
// Tell the world what we are up to
printf("[pl_volume] Software volume control in use.\n");
printf("[pl_volume] Software volume control in use%s.\n",ao_plugin_cfg.pl_volume_softclip?", soft clipping enabled":"");
return 1;
}
@ -100,24 +108,54 @@ static void uninit(){
static void reset(){
}
#define SIGN(x) (x>0?1:-1)
// processes 'ao_plugin_data.len' bytes of 'data'
// called for every block of data
static int play(){
register int i=0;
register int vol=pl_volume.volume; // Logarithmic control sounds more natural
vol=(vol*vol*vol)>>12;
// Change the volume.
switch(pl_volume.format){
case(AFMT_U8):{
register uint8_t* data=(uint8_t*)ao_plugin_data.data;
for(i=0;i<ao_plugin_data.len;i++){
data[i]=(((data[i]-128) * pl_volume.volume) >> 8) + 128;
}
break;
register int x;
for(i=0;i<ao_plugin_data.len;i++){
x=((data[i]-128) * vol) >> 8;
if(x>MAX_S8)
data[i]=MAX_U8;
else if(x<MIN_S8)
data[i]=MIN_U8;
else{
if(ao_plugin_cfg.pl_volume_softclip)
data[i] = ((3*x - ((x*x*x) >> 14)) >> 1) + 128;
else
data[i] = x + 128;
}
}
break;
}
case(AFMT_S16_LE):{
register int len=ao_plugin_data.len>>1;
register int16_t* data=(int16_t*)ao_plugin_data.data;
for(i=0;i<len;i++)
data[i]=(data[i]* pl_volume.volume)>>8;
register int x;
for(i=0;i<len;i++){
x=(data[i] * vol) >> 8;
if(x>MAX_S16)
data[i]=MAX_S16;
else if(x<MIN_S16)
data[i]=MIN_S16;
else{
if(ao_plugin_cfg.pl_volume_softclip){
int64_t t=x*x;
t=(t*x) >> 30;
data[i] = (3*x - (int)t) >> 1;
//data[i] = 2*x - SIGN(x)*((x*x)>>15);
}
else
data[i] = x;
}
}
break;
}
default:
@ -126,8 +164,3 @@ static int play(){
return 1;
}