mpv/libmpcodecs/ad_msgsm.c

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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 =
{
"native GSM/MSGSM audio decoder",
"msgsm",
"A'rpi",
"XAnim",
""
};
LIBAD_EXTERN(msgsm)
#include "xa_gsm.h"
static int init(sh_audio_t *sh_audio)
{
if(!sh_audio->wf) return 0;
// MS-GSM audio codec:
GSM_Init();
sh_audio->channels=sh_audio->wf->nChannels;
sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
sh_audio->samplesize=2;
// decodes 65 byte -> 320 short
// 1 sec: sh_audio->channels*sh_audio->samplerate samples
// 1 frame: 320 samples
if(sh_audio->format==0x31 || sh_audio->format==0x32){
sh_audio->ds->ss_mul=65; sh_audio->ds->ss_div=320;
} else {
sh_audio->ds->ss_mul=33; sh_audio->ds->ss_div=160;
}
sh_audio->i_bps=sh_audio->ds->ss_mul*(sh_audio->channels*sh_audio->samplerate)/sh_audio->ds->ss_div; // 1:10
return 1;
}
static int preinit(sh_audio_t *sh_audio)
{
sh_audio->audio_out_minsize=4*320;
return 1;
}
static void uninit(sh_audio_t *sh)
{
}
static int control(sh_audio_t *sh,int cmd,void* arg, ...)
{
return CONTROL_UNKNOWN;
}
static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
{
if(sh_audio->format==0x31 || sh_audio->format==0x32){
unsigned char ibuf[65]; // 65 bytes / frame
if(demux_read_data(sh_audio->ds,ibuf,65)!=65) return -1; // EOF
XA_MSGSM_Decoder(ibuf,(unsigned short *) buf); // decodes 65 byte -> 320 short
return 2*320;
} else {
unsigned char ibuf[33]; // 33 bytes / frame
if(demux_read_data(sh_audio->ds,ibuf,33)!=33) return -1; // EOF
XA_GSM_Decoder(ibuf,(unsigned short *) buf); // decodes 33 byte -> 160 short
return 2*160;
}
}