ac32spdif.c

   1 \r
   2 #include <stdio.h>\r
   3 //#include <stdlib.h>\r
   4 //#include <string.h>\r
   5 #include <memory.h>\r
   6 \r
   7 //#include "fs_codes.h"\r
   8 \r
   9 \r
  10 short bitrates[] = { 32,  40,  48,  56,  64,  80,  96, 112, 128, 160,\r
  11 192, 224, 256, 320, 384, 448, 512, 576, 640 };\r
  12 \r
  13 short fsize44[] = {  70,   88,  105,  122,  140,  175,  209,  244,  279,  349,\r
  14 418,  488,  558,  697,  836,  976, 1115, 1254, 1394 };\r
  15 \r
  16 unsigned long DecFS(char sratecode, unsigned long fsizecode)\r
  17 {\r
  18         switch (sratecode)\r
  19         {\r
  20                 case 0:\r
  21                         return (bitrates[fsizecode / 2] * 2);\r
  22                 case 1:\r
  23                         return ((fsizecode % 2) ? fsize44[fsizecode / 2] : fsize44[fsizecode / 2] - 1);\r
  24                 case 2:\r
  25                         return (bitrates[fsizecode / 2] * 3);\r
  26                 default:\r
  27                         return 0;\r
  28         }\r
  29 \r
  30         return 0;\r
  31 }\r
  32 \r
  33 \r
  34 \r
  35 \r
  36 struct WAVEHEADER {\r
  37     unsigned long  ChunkID;\r
  38     unsigned long  ChunkSize;\r
  39     unsigned long  Format;\r
  40     unsigned long  SubChunk1ID;\r
  41     unsigned long  SubChunk1Size;\r
  42     unsigned short AudioFormat;\r
  43     unsigned short NumChannels;\r
  44     unsigned long  SampleRate;\r
  45     unsigned long  ByteRate;\r
  46     unsigned short BlockAlign;\r
  47     unsigned short BitsPerSample;\r
  48     unsigned long  SubChunk2ID;\r
  49     unsigned long  SubChunk2Size;\r
  50 };\r
  51 \r
  52 \r
  53 struct AC3PREAMBLE {\r
  54         unsigned short sync1;\r
  55         unsigned short sync2;\r
  56         unsigned char burst_infoLSB;\r
  57         unsigned char burst_infoMSB;\r
  58         unsigned short lengthcode;\r
  59 };\r
  60 \r
  61 char burst[6144];\r
  62 \r
  63 FILE *infile, *outfile;\r
  64 \r
  65 unsigned long bytesread;\r
  66 unsigned long payloadbytes;\r
  67 char sampleratecode;\r
  68 unsigned long framesizecode;\r
  69 \r
  70 struct AC3PREAMBLE ac3p = { 0xF872, 0x4E1F, 1, 0, 0x3800 };\r
  71 struct WAVEHEADER wavhdr = { 0x46464952,\r
  72                                                         0,\r
  73                                                         0x45564157,\r
  74                                                         0x20746D66,\r
  75                                                         16,\r
  76                                                         1,\r
  77                                                         2,\r
  78                                                         0,\r
  79                                                         0,\r
  80                                                         4,\r
  81                                                         16,\r
  82                                                         0x61746164,\r
  83                                                         0 };\r
  84 \r
  85 unsigned long i;\r
  86 char temp;\r
  87 \r
  88 int main( int argc, char *argv[ ], char *envp[ ] )\r
  89 {\r
  90         if (argc < 3)\r
  91         {\r
  92                 printf("Wrong syntax. AC3PACK <In.ac3> <Out.wav>.\n");\r
  93                 return 0;\r
  94         }\r
  95 \r
  96         infile = fopen(argv[1], "rb");\r
  97         outfile = fopen(argv[2], "wb");\r
  98         //fseek(outfile, SEEK_SET, 44);\r
  99         fwrite (&wavhdr, sizeof(struct WAVEHEADER), 1, outfile);\r
 100 \r
 101 \r
 102 \r
 103         for(;;)\r
 104         {\r
 105                 memset (burst, 0, 6144);\r
 106                 bytesread = fread(&burst[8], 1, 6, infile);\r
 107                 if (bytesread < 6)\r
 108                 {\r
 109                         printf ("EOF reached (Frame Header reading)!\nCurrent position in INFILE: %i\n", ftell(infile));\r
 110                         break;\r
 111                 }\r
 112                 if ((burst[8] != 0x0B) || (burst[9] != 0x77))\r
 113                 {\r
 114                         printf("ERROR: INVALID SYNCWORD !\nCurrent position in INFILE: %i\n", ftell(infile));\r
 115                         break;\r
 116                 }\r
 117                 framesizecode = (burst[12] & 63);\r
 118                 sampleratecode = ((burst[12] & 192) / 64);\r
 119 \r
 120                 if (wavhdr.SampleRate == 0)\r
 121                 {\r
 122                                 printf ("First Sampleratecode: %i\n", sampleratecode);\r
 123 \r
 124                                 switch (sampleratecode)\r
 125                                 {\r
 126                                 case 0:\r
 127                                         wavhdr.SampleRate = 48000;\r
 128                                         wavhdr.ByteRate = 192000;\r
 129                                         break;\r
 130                                 case 1:\r
 131                                         wavhdr.SampleRate = 44100;\r
 132                                         wavhdr.ByteRate = 176000;\r
 133                                         break;\r
 134                                 case 2:\r
 135                                         wavhdr.SampleRate = 32000;\r
 136                                         wavhdr.ByteRate = 128000;\r
 137                                         break;\r
 138                                 default:\r
 139                                         wavhdr.SampleRate = 48000;\r
 140                                         wavhdr.ByteRate = 192000;\r
 141                                 }\r
 142                 }\r
 143 \r
 144                 payloadbytes = DecFS (sampleratecode, framesizecode);\r
 145                 payloadbytes *= 2;\r
 146 \r
 147                 bytesread = fread (&burst[14], 1, payloadbytes - 6, infile);\r
 148                 if ((bytesread + 6) < payloadbytes)\r
 149                 {\r
 150                         printf ("EOF reached (Burst Reading)!\nCurrent position in INFILE: %i\n", ftell(infile));\r
 151                         printf ("Frame size: %i  .. Bytes read: %i\n", payloadbytes, bytesread);\r
 152                         break;\r
 153                 }\r
 154                 ac3p.burst_infoMSB = (burst[13] & 7);\r
 155                 ac3p.lengthcode = (short)(payloadbytes * 8);\r
 156 \r
 157                 for (i = 8; i < (payloadbytes + 8); i += 2)\r
 158                 {\r
 159                         temp = burst[i];\r
 160                         burst[i] = burst[i + 1];\r
 161                         burst[i + 1] = temp;\r
 162                 }\r
 163 \r
 164                 memcpy (burst, &ac3p, sizeof(struct AC3PREAMBLE));\r
 165 \r
 166                 fwrite (burst, 1, 6144, outfile);\r
 167 \r
 168         }\r
 169 \r
 170         printf ("Last Sampleratecode: %i\n", sampleratecode);\r
 171 \r
 172         wavhdr.SubChunk2Size = (ftell(outfile) - 44);\r
 173         wavhdr.ChunkSize = wavhdr.SubChunk2Size + 36;\r
 174 \r
 175         fseek (outfile, SEEK_SET, 0);\r
 176         fwrite (&wavhdr, sizeof(struct WAVEHEADER), 1, outfile);\r
 177 \r
 178         fclose (infile);\r
 179         fclose (outfile);\r
 180 \r
 181         return 0;\r
 182 }\r