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/*
* Copyright (C)2002 Anders Johansson ajh@atri.curtin.edu.au
*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <math.h>
#include <limits.h>
#include "af.h"
// Data for specific instances of this filter
typedef struct af_volume_s
{
float level[AF_NCH]; // Gain level for each channel
int soft; // Enable/disable soft clipping
int fast; // Use fix-point volume control
}af_volume_t;
// Initialization and runtime control
static int control(struct af_instance* af, int cmd, void* arg)
{
af_volume_t* s = (af_volume_t*)af->setup;
switch(cmd){
case AF_CONTROL_REINIT:
// Sanity check
if(!arg) return AF_ERROR;
mp_audio_copy_config(af->data, (struct mp_audio*)arg);
if(s->fast && (((struct mp_audio*)arg)->format != (AF_FORMAT_FLOAT_NE))){
mp_audio_set_format(af->data, AF_FORMAT_S16_NE);
}
else{
// Cutoff set to 10Hz for forgetting factor
mp_audio_set_format(af->data, AF_FORMAT_FLOAT_NE);
}
return af_test_output(af,(struct mp_audio*)arg);
case AF_CONTROL_COMMAND_LINE:{
float v=1000.0;
float vol[AF_NCH];
int i;
sscanf((char*)arg,"%f:%i:%i", &v, &s->soft, &s->fast);
float dest = 0.0;
if (v < 1000)
af_from_dB(1,&v,&dest,20.0,-200.0,60.0);
for(i=0;i<AF_NCH;i++) vol[i]=dest;
return control(af,AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET, vol);
}
case AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_SET:
memcpy(s->level, arg, sizeof(float) * AF_NCH);
return AF_OK;
case AF_CONTROL_VOLUME_LEVEL | AF_CONTROL_GET:
memcpy(arg, s->level, sizeof(float) * AF_NCH);
return AF_OK;
}
return AF_UNKNOWN;
}
// Deallocate memory
static void uninit(struct af_instance* af)
{
free(af->data);
free(af->setup);
}
// Filter data through filter
static struct mp_audio* play(struct af_instance* af, struct mp_audio* data)
{
struct mp_audio* c = data; // Current working data
af_volume_t* s = (af_volume_t*)af->setup; // Setup for this instance
register int nch = c->nch; // Number of channels
register int i = 0;
// Basic operation volume control only (used on slow machines)
if(af->data->format == (AF_FORMAT_S16_NE)){
int16_t* a = (int16_t*)c->audio; // Audio data
int len = c->len/2; // Number of samples
for (int ch = 0; ch < nch; ch++) {
int vol = 256.0 * s->level[ch];
if (vol != 256) {
for(i=ch;i<len;i+=nch){
register int x = (a[i] * vol) >> 8;
a[i]=clamp(x,SHRT_MIN,SHRT_MAX);
}
}
}
}
// Machine is fast and data is floating point
else if(af->data->format == (AF_FORMAT_FLOAT_NE)){
float* a = (float*)c->audio; // Audio data
int len = c->len/4; // Number of samples
for (int ch = 0; ch < nch; ch++) {
// Volume control (fader)
for(i=ch;i<len;i+=nch){
register float x = a[i];
// Set volume
x *= s->level[ch];
/* Soft clipping, the sound of a dream, thanks to Jon Wattes
post to Musicdsp.org */
if(s->soft)
x=af_softclip(x);
// Hard clipping
else
x=clamp(x,-1.0,1.0);
a[i] = x;
}
}
}
return c;
}
// Allocate memory and set function pointers
static int af_open(struct af_instance* af){
int i = 0;
af->control=control;
af->uninit=uninit;
af->play=play;
af->mul=1;
af->data=calloc(1,sizeof(struct mp_audio));
af->setup=calloc(1,sizeof(af_volume_t));
if(af->data == NULL || af->setup == NULL)
return AF_ERROR;
// Enable volume control and set initial volume to 0dB.
for(i=0;i<AF_NCH;i++){
((af_volume_t*)af->setup)->level[i] = 1.0;
}
return AF_OK;
}
// Description of this filter
struct af_info af_info_volume = {
.info = "Volume control audio filter",
.name = "volume",
.flags = AF_FLAGS_NOT_REENTRANT,
.open = af_open,
};
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