libmpcodecs/ad_msgsm.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4
   5 #include "config.h"
   6 #include "ad_internal.h"
   7
   8 static ad_info_t info =
   9 {
  10         "native GSM/MSGSM audio decoder",
  11         "msgsm",
  12         "A'rpi",
  13         "XAnim",
  14         ""
  15 };
  16
  17 LIBAD_EXTERN(msgsm)
  18
  19 #include "native/xa_gsm.h"
  20
  21 static int init(sh_audio_t *sh_audio)
  22 {
  23   if(!sh_audio->wf) return 0;
  24   // MS-GSM audio codec:
  25   GSM_Init();
  26   sh_audio->channels=sh_audio->wf->nChannels;
  27   sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
  28   sh_audio->samplesize=2;
  29   // decodes 65 byte -> 320 short
  30   // 1 sec: sh_audio->channels*sh_audio->samplerate  samples
  31   // 1 frame: 320 samples
  32   if(sh_audio->format==0x31 || sh_audio->format==0x32){
  33     sh_audio->ds->ss_mul=65; sh_audio->ds->ss_div=320;
  34   } else {
  35     sh_audio->ds->ss_mul=33; sh_audio->ds->ss_div=160;
  36   }
  37   sh_audio->i_bps=sh_audio->ds->ss_mul*(sh_audio->channels*sh_audio->samplerate)/sh_audio->ds->ss_div;  // 1:10
  38   return 1;
  39 }
  40
  41 static int preinit(sh_audio_t *sh_audio)
  42 {
  43   sh_audio->audio_out_minsize=4*320;
  44   return 1;
  45 }
  46
  47 static void uninit(sh_audio_t *sh)
  48 {
  49 }
  50
  51 static int control(sh_audio_t *sh,int cmd,void* arg, ...)
  52 {
  53   return CONTROL_UNKNOWN;
  54 }
  55
  56 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
  57 {
  58   if(sh_audio->format==0x31 || sh_audio->format==0x32){
  59     unsigned char ibuf[65]; // 65 bytes / frame
  60     if(demux_read_data(sh_audio->ds,ibuf,65)!=65) return -1; // EOF
  61     XA_MSGSM_Decoder(ibuf,(unsigned short *) buf); // decodes 65 byte -> 320 short
  62     return 2*320;
  63   } else {
  64     unsigned char ibuf[33]; // 33 bytes / frame
  65     if(demux_read_data(sh_audio->ds,ibuf,33)!=33) return -1; // EOF
  66     XA_GSM_Decoder(ibuf,(unsigned short *) buf); // decodes 33 byte -> 160 short
  67     return 2*160;
  68   }
  69 }