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/*=============================================================================
//
// This software has been released under the terms of the GNU General Public
// license. See http://www.gnu.org/copyleft/gpl.html for details.
//
// Copyright 2002 Anders Johansson ajh@atri.curtin.edu.au
//
//=============================================================================
*/
/* */
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include <math.h>
#include <limits.h>
#include "af.h"
// Data for specific instances of this filter
typedef struct af_pan_s
{
int nch; // Number of output channels; zero means same as input
float level[AF_NCH][AF_NCH]; // Gain level for each channel
}af_pan_t;
// Initialization and runtime control
static int control(struct af_instance_s* af, int cmd, void* arg)
{
af_pan_t* s = af->setup;
switch(cmd){
case AF_CONTROL_REINIT:
// Sanity check
if(!arg) return AF_ERROR;
af->data->rate = ((af_data_t*)arg)->rate;
af->data->format = AF_FORMAT_FLOAT_NE;
af->data->bps = 4;
af->data->nch = s->nch ? s->nch: ((af_data_t*)arg)->nch;
af->mul.n = af->data->nch;
af->mul.d = ((af_data_t*)arg)->nch;
af_frac_cancel(&af->mul);
if((af->data->format != ((af_data_t*)arg)->format) ||
(af->data->bps != ((af_data_t*)arg)->bps)){
((af_data_t*)arg)->format = af->data->format;
((af_data_t*)arg)->bps = af->data->bps;
return AF_FALSE;
}
return AF_OK;
case AF_CONTROL_COMMAND_LINE:{
int nch = 0;
int n = 0;
char* cp = NULL;
int j,k;
// Read number of outputs
sscanf((char*)arg,"%i%n", &nch,&n);
if(AF_OK != control(af,AF_CONTROL_PAN_NOUT | AF_CONTROL_SET, &nch))
return AF_ERROR;
// Read pan values
cp = &((char*)arg)[n];
j = 0; k = 0;
while((*cp == ':') && (k < AF_NCH)){
sscanf(cp, ":%f%n" , &s->level[j][k], &n);
af_msg(AF_MSG_VERBOSE,"[pan] Pan level from channel %i to"
" channel %i = %f\n",k,j,s->level[j][k]);
cp =&cp[n];
j++;
if(j>=nch){
j = 0;
k++;
}
}
return AF_OK;
}
case AF_CONTROL_PAN_LEVEL | AF_CONTROL_SET:{
int i;
int ch = ((af_control_ext_t*)arg)->ch;
float* level = ((af_control_ext_t*)arg)->arg;
if (ch >= AF_NCH)
return AF_FALSE;
for(i=0;i<AF_NCH;i++)
s->level[ch][i] = level[i];
return AF_OK;
}
case AF_CONTROL_PAN_LEVEL | AF_CONTROL_GET:{
int i;
int ch = ((af_control_ext_t*)arg)->ch;
float* level = ((af_control_ext_t*)arg)->arg;
if (ch >= AF_NCH)
return AF_FALSE;
for(i=0;i<AF_NCH;i++)
level[i] = s->level[ch][i];
return AF_OK;
}
case AF_CONTROL_PAN_NOUT | AF_CONTROL_SET:
// Reinit must be called after this function has been called
// Sanity check
if(((int*)arg)[0] <= 0 || ((int*)arg)[0] > AF_NCH){
af_msg(AF_MSG_ERROR,"[pan] The number of output channels must be"
" between 1 and %i. Current value is %i\n",AF_NCH,((int*)arg)[0]);
return AF_ERROR;
}
s->nch=((int*)arg)[0];
return AF_OK;
case AF_CONTROL_PAN_NOUT | AF_CONTROL_GET:
*(int*)arg = af->data->nch;
return AF_OK;
case AF_CONTROL_PAN_BALANCE | AF_CONTROL_SET:{
float val = *(float*)arg;
if (s->nch)
return AF_ERROR;
if (af->data->nch >= 2) {
s->level[0][0] = min(1.f, 1.f - val);
s->level[0][1] = max(0.f, val);
s->level[1][0] = max(0.f, -val);
s->level[1][1] = min(1.f, 1.f + val);
}
return AF_OK;
}
case AF_CONTROL_PAN_BALANCE | AF_CONTROL_GET:
if (s->nch)
return AF_ERROR;
*(float*)arg = s->level[0][1] - s->level[1][0];
return AF_OK;
}
return AF_UNKNOWN;
}
// Deallocate memory
static void uninit(struct af_instance_s* af)
{
if(af->data)
free(af->data->audio);
free(af->data);
if(af->setup)
free(af->setup);
}
// Filter data through filter
static af_data_t* play(struct af_instance_s* af, af_data_t* data)
{
af_data_t* c = data; // Current working data
af_data_t* l = af->data; // Local data
af_pan_t* s = af->setup; // Setup for this instance
float* in = c->audio; // Input audio data
float* out = NULL; // Output audio data
float* end = in+c->len/4; // End of loop
int nchi = c->nch; // Number of input channels
int ncho = l->nch; // Number of output channels
register int j,k;
if(AF_OK != RESIZE_LOCAL_BUFFER(af,data))
return NULL;
out = l->audio;
// Execute panning
// FIXME: Too slow
while(in < end){
for(j=0;j<ncho;j++){
register float x = 0.0;
register float* tin = in;
for(k=0;k<nchi;k++)
x += tin[k] * s->level[j][k];
out[j] = x;
}
out+= ncho;
in+= nchi;
}
// Set output data
c->audio = l->audio;
c->len = (c->len*af->mul.n)/af->mul.d;
c->nch = l->nch;
return c;
}
// Allocate memory and set function pointers
static int af_open(af_instance_t* af){
af->control=control;
af->uninit=uninit;
af->play=play;
af->mul.n=1;
af->mul.d=1;
af->data=calloc(1,sizeof(af_data_t));
af->setup=calloc(1,sizeof(af_pan_t));
if(af->data == NULL || af->setup == NULL)
return AF_ERROR;
return AF_OK;
}
// Description of this filter
af_info_t af_info_pan = {
"Panning audio filter",
"pan",
"Anders",
"",
AF_FLAGS_REENTRANT,
af_open
};
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