libmpcodecs/ad_dvdpcm.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <unistd.h>
   4
   5 #include "config.h"
   6 #include "mp_msg.h"
   7 #include "help_mp.h"
   8 #include "ad_internal.h"
   9
  10 static ad_info_t info =
  11 {
  12         "Uncompressed DVD/VOB LPCM audio decoder",
  13         "dvdpcm",
  14         "Nick Kurshev",
  15         "A'rpi",
  16         ""
  17 };
  18
  19 LIBAD_EXTERN(dvdpcm)
  20
  21 static int init(sh_audio_t *sh)
  22 {
  23 /* DVD PCM Audio:*/
  24     sh->i_bps = 0;
  25     if(sh->codecdata_len==3){
  26         // we have LPCM header:
  27         unsigned char h=sh->codecdata[1];
  28         sh->channels=1+(h&7);
  29         switch((h>>4)&3){
  30         case 0: sh->samplerate=48000;break;
  31         case 1: sh->samplerate=96000;break;
  32         case 2: sh->samplerate=44100;break;
  33         case 3: sh->samplerate=32000;break;
  34         }
  35         switch ((h >> 6) & 3) {
  36           case 0:
  37             sh->sample_format = AF_FORMAT_S16_BE;
  38             sh->samplesize = 2;
  39             break;
  40           case 1:
  41             mp_msg(MSGT_DECAUDIO, MSGL_INFO, MSGTR_SamplesWanted);
  42             sh->i_bps = sh->channels * sh->samplerate * 5 / 2;
  43           case 2:
  44             sh->sample_format = AF_FORMAT_S24_BE;
  45             sh->samplesize = 3;
  46             break;
  47           default:
  48             sh->sample_format = AF_FORMAT_S16_BE;
  49             sh->samplesize = 2;
  50         }
  51     } else {
  52         // use defaults:
  53         sh->channels=2;
  54         sh->samplerate=48000;
  55         sh->sample_format = AF_FORMAT_S16_BE;
  56         sh->samplesize = 2;
  57     }
  58     if (!sh->i_bps)
  59     sh->i_bps = sh->samplesize * sh->channels * sh->samplerate;
  60     return 1;
  61 }
  62
  63 static int preinit(sh_audio_t *sh)
  64 {
  65   sh->audio_out_minsize=2048;
  66   return 1;
  67 }
  68
  69 static void uninit(sh_audio_t *sh)
  70 {
  71 }
  72
  73 static int control(sh_audio_t *sh,int cmd,void* arg, ...)
  74 {
  75   int skip;
  76     switch(cmd)
  77     {
  78       case ADCTRL_SKIP_FRAME:
  79         skip=sh->i_bps/16;
  80         skip=skip&(~3);
  81         demux_read_data(sh->ds,NULL,skip);
  82         return CONTROL_TRUE;
  83     }
  84   return CONTROL_UNKNOWN;
  85 }
  86
  87 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
  88 {
  89   int j,len;
  90   if (sh_audio->samplesize == 3) {
  91     if (((sh_audio->codecdata[1] >> 6) & 3) == 1) {
  92       // 20 bit
  93       // not sure if the "& 0xf0" and "<< 4" are the right way around
  94       // can somebody clarify?
  95       for (j = 0; j < minlen; j += 12) {
  96         char tmp[10];
  97         len = demux_read_data(sh_audio->ds, tmp, 10);
  98         if (len < 10) break;
  99         // first sample
 100         buf[j + 0] = tmp[0];
 101         buf[j + 1] = tmp[1];
 102         buf[j + 2] = tmp[8] & 0xf0;
 103         // second sample
 104         buf[j + 3] = tmp[2];
 105         buf[j + 4] = tmp[3];
 106         buf[j + 5] = tmp[8] << 4;
 107         // third sample
 108         buf[j + 6] = tmp[4];
 109         buf[j + 7] = tmp[5];
 110         buf[j + 8] = tmp[9] & 0xf0;
 111         // fourth sample
 112         buf[j + 9] = tmp[6];
 113         buf[j + 10] = tmp[7];
 114         buf[j + 11] = tmp[9] << 4;
 115       }
 116       len = j;
 117     } else {
 118       // 24 bit
 119       for (j = 0; j < minlen; j += 12) {
 120         char tmp[12];
 121         len = demux_read_data(sh_audio->ds, tmp, 12);
 122         if (len < 12) break;
 123         // first sample
 124         buf[j + 0] = tmp[0];
 125         buf[j + 1] = tmp[1];
 126         buf[j + 2] = tmp[8];
 127         // second sample
 128         buf[j + 3] = tmp[2];
 129         buf[j + 4] = tmp[3];
 130         buf[j + 5] = tmp[9];
 131         // third sample
 132         buf[j + 6] = tmp[4];
 133         buf[j + 7] = tmp[5];
 134         buf[j + 8] = tmp[10];
 135         // fourth sample
 136         buf[j + 9] = tmp[6];
 137         buf[j + 10] = tmp[7];
 138         buf[j + 11] = tmp[11];
 139       }
 140       len = j;
 141     }
 142   } else
 143   len=demux_read_data(sh_audio->ds,buf,(minlen+3)&(~3));
 144   return len;
 145 }