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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "ad_internal.h"
static ad_info_t info =
{
"aLaw/uLaw audio decoder",
"alaw",
"Nick Kurshev",
"A'rpi",
""
};
LIBAD_EXTERN(alaw)
#include "native/alaw.h"
static int init(sh_audio_t *sh_audio)
{
/* aLaw audio codec:*/
if(!sh_audio->wf) return 0;
sh_audio->channels=sh_audio->wf->nChannels;
sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
sh_audio->i_bps=sh_audio->channels*sh_audio->samplerate;
sh_audio->samplesize=2;
return 1;
}
static int preinit(sh_audio_t *sh)
{
sh->audio_out_minsize=2048;
sh->ds->ss_div = 1; // 1 samples/packet
sh->ds->ss_mul = sh->wf->nChannels; // bytes/packet
return 1;
}
static void uninit(sh_audio_t *sh)
{
}
static int control(sh_audio_t *sh,int cmd,void* arg, ...)
{
int skip;
switch(cmd)
{
case ADCTRL_SKIP_FRAME:
skip=sh->i_bps/16;
skip=skip&(~3);
demux_read_data(sh->ds,NULL,skip);
return CONTROL_TRUE;
default:
return CONTROL_UNKNOWN;
}
return CONTROL_UNKNOWN;
}
static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
{
int len;
int l=demux_read_data(sh_audio->ds,buf,minlen/2);
unsigned short *d=(unsigned short *) buf;
unsigned char *s=buf;
len=2*l;
if(sh_audio->format==6 || sh_audio->format==0x77616C61){
/* aLaw */
while(l>0){ --l; d[l]=alaw2short[s[l]]; }
} else {
/* uLaw */
while(l>0){ --l; d[l]=ulaw2short[s[l]]; }
}
return len;
}
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