mpv/libaf/af_channels.c

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/* Audio filter that adds and removes channels, according to the
command line parameter channels. It is stupid and can only add
silence or copy channels not mix or filter.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "../config.h"
#include "../mp_msg.h"
#include "af.h"
// Local function for copying data
void copy(void* in, void* out, int ins, int inos,int outs, int outos, int len, int bps)
{
switch(bps){
case 1:{
int8_t* tin = (int8_t*)in;
int8_t* tout = (int8_t*)out;
tin += inos;
tout += outos;
len = len/ins;
while(len--){
*tout=*tin;
tin +=ins;
tout+=outs;
}
break;
}
case 2:{
int16_t* tin = (int16_t*)in;
int16_t* tout = (int16_t*)out;
tin += inos;
tout += outos;
len = len/(2*ins);
while(len--){
*tout=*tin;
tin +=ins;
tout+=outs;
}
break;
}
case 4:{
int32_t* tin = (int32_t*)in;
int32_t* tout = (int32_t*)out;
tin += inos;
tout += outos;
len = len/(4*ins);
while(len--){
*tout=*tin;
tin +=ins;
tout+=outs;
}
break;
}
case 8:{
int64_t* tin = (int64_t*)in;
int64_t* tout = (int64_t*)out;
tin += inos;
tout += outos;
len = len/(8*ins);
while(len--){
*tout=*tin;
tin +=ins;
tout+=outs;
}
break;
}
default:
mp_msg(MSGT_AFILTER,MSGL_ERR,"[channels] Unsupported number of bytes/sample: %i please report this error on the MPlayer mailing list. \n",bps);
}
}
// Initialization and runtime control
static int control(struct af_instance_s* af, int cmd, void* arg)
{
switch(cmd){
case AF_CONTROL_REINIT:
// Make sure this filter isn't redundant
if(af->data->nch == ((af_data_t*)arg)->nch)
return AF_DETACH;
af->data->rate = ((af_data_t*)arg)->rate;
af->data->format = ((af_data_t*)arg)->format;
af->data->bps = ((af_data_t*)arg)->bps;
af->mul.n = af->data->nch;
af->mul.d = ((af_data_t*)arg)->nch;
return AF_OK;
case AF_CONTROL_CHANNELS:
// Reinit must be called after this function has been called
// Sanity check
if(((int*)arg)[0] <= 0 || ((int*)arg)[0] > 6){
mp_msg(MSGT_AFILTER,MSGL_ERR,"[channels] The number of output channels must be between 1 and 6. Current value is%i \n",((int*)arg)[0]);
return AF_ERROR;
}
af->data->nch=((int*)arg)[0];
mp_msg(MSGT_AFILTER,MSGL_V,"[channels] Changing number of channels to %i\n",af->data->nch);
return AF_OK;
}
return AF_UNKNOWN;
}
// Deallocate memory
static void uninit(struct af_instance_s* af)
{
if(af->data)
free(af->data);
}
// 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
if(AF_OK != RESIZE_LOCAL_BUFFER(af,data))
return NULL;
// Reset unused channels if nch in < nch out
if(af->mul.n > af->mul.d)
memset(l->audio,0,(c->len*af->mul.n)/af->mul.d);
// Special case always output L & R
if(c->nch == 1){
copy(c->audio,l->audio,1,0,l->nch,0,c->len,c->bps);
copy(c->audio,l->audio,1,0,l->nch,1,c->len,c->bps);
}
else{
int i;
if(l->nch < c->nch){
for(i=0;i<l->nch;i++) // Truncates R if l->nch == 1 not good need mixing
copy(c->audio,l->audio,c->nch,i,l->nch,i,c->len,c->bps);
}
else{
for(i=0;i<c->nch;i++)
copy(c->audio,l->audio,c->nch,i,l->nch,i,c->len,c->bps);
}
}
// 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 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));
if(af->data == NULL)
return AF_ERROR;
return AF_OK;
}
// Description of this filter
af_info_t af_info_channels = {
"Insert or remove channels",
"channels",
"Anders",
"",
AF_FLAGS_REENTRANT,
open
};