diff options
Diffstat (limited to 'libao2')
| -rw-r--r-- | libao2/audio_plugin.h | 6 | ||||
| -rw-r--r-- | libao2/pl_volume.c | 57 |
2 files changed, 49 insertions, 14 deletions
diff --git a/libao2/audio_plugin.h b/libao2/audio_plugin.h index 4d31c19bf2..2ff06591b5 100644 --- a/libao2/audio_plugin.h +++ b/libao2/audio_plugin.h @@ -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 diff --git a/libao2/pl_volume.c b/libao2/pl_volume.c index 8c31cae92f..a6590cce16 100644 --- a/libao2/pl_volume.c +++ b/libao2/pl_volume.c @@ -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; } - - - - - |