alawulaw.c

   1 /*****************************************************************************\
   2 **                                                                           **
   3 ** PBX4Linux                                                                 **
   4 **                                                                           **
   5 **---------------------------------------------------------------------------**
   6 ** Copyright: Andreas Eversberg                                              **
   7 **                                                                           **
   8 ** audio conversions for alaw and ulaw                                       **
   9 **                                                                           **
  10 \*****************************************************************************/
  11
  12 signed int *audio_law_to_s32;
  13 unsigned char silence;
  14
  15 /* ulaw -> signed 16-bit */
  16 static signed int audio_ulaw_to_s32[] =
  17 {
  18         0xffff8284, 0xffff8684, 0xffff8a84, 0xffff8e84,
  19         0xffff9284, 0xffff9684, 0xffff9a84, 0xffff9e84,
  20         0xffffa284, 0xffffa684, 0xffffaa84, 0xffffae84,
  21         0xffffb284, 0xffffb684, 0xffffba84, 0xffffbe84,
  22         0xffffc184, 0xffffc384, 0xffffc584, 0xffffc784,
  23         0xffffc984, 0xffffcb84, 0xffffcd84, 0xffffcf84,
  24         0xffffd184, 0xffffd384, 0xffffd584, 0xffffd784,
  25         0xffffd984, 0xffffdb84, 0xffffdd84, 0xffffdf84,
  26         0xffffe104, 0xffffe204, 0xffffe304, 0xffffe404,
  27         0xffffe504, 0xffffe604, 0xffffe704, 0xffffe804,
  28         0xffffe904, 0xffffea04, 0xffffeb04, 0xffffec04,
  29         0xffffed04, 0xffffee04, 0xffffef04, 0xfffff004,
  30         0xfffff0c4, 0xfffff144, 0xfffff1c4, 0xfffff244,
  31         0xfffff2c4, 0xfffff344, 0xfffff3c4, 0xfffff444,
  32         0xfffff4c4, 0xfffff544, 0xfffff5c4, 0xfffff644,
  33         0xfffff6c4, 0xfffff744, 0xfffff7c4, 0xfffff844,
  34         0xfffff8a4, 0xfffff8e4, 0xfffff924, 0xfffff964,
  35         0xfffff9a4, 0xfffff9e4, 0xfffffa24, 0xfffffa64,
  36         0xfffffaa4, 0xfffffae4, 0xfffffb24, 0xfffffb64,
  37         0xfffffba4, 0xfffffbe4, 0xfffffc24, 0xfffffc64,
  38         0xfffffc94, 0xfffffcb4, 0xfffffcd4, 0xfffffcf4,
  39         0xfffffd14, 0xfffffd34, 0xfffffd54, 0xfffffd74,
  40         0xfffffd94, 0xfffffdb4, 0xfffffdd4, 0xfffffdf4,
  41         0xfffffe14, 0xfffffe34, 0xfffffe54, 0xfffffe74,
  42         0xfffffe8c, 0xfffffe9c, 0xfffffeac, 0xfffffebc,
  43         0xfffffecc, 0xfffffedc, 0xfffffeec, 0xfffffefc,
  44         0xffffff0c, 0xffffff1c, 0xffffff2c, 0xffffff3c,
  45         0xffffff4c, 0xffffff5c, 0xffffff6c, 0xffffff7c,
  46         0xffffff88, 0xffffff90, 0xffffff98, 0xffffffa0,
  47         0xffffffa8, 0xffffffb0, 0xffffffb8, 0xffffffc0,
  48         0xffffffc8, 0xffffffd0, 0xffffffd8, 0xffffffe0,
  49         0xffffffe8, 0xfffffff0, 0xfffffff8, 0xffffffff,
  50         0x00007d7c, 0x0000797c, 0x0000757c, 0x0000717c,
  51         0x00006d7c, 0x0000697c, 0x0000657c, 0x0000617c,
  52         0x00005d7c, 0x0000597c, 0x0000557c, 0x0000517c,
  53         0x00004d7c, 0x0000497c, 0x0000457c, 0x0000417c,
  54         0x00003e7c, 0x00003c7c, 0x00003a7c, 0x0000387c,
  55         0x0000367c, 0x0000347c, 0x0000327c, 0x0000307c,
  56         0x00002e7c, 0x00002c7c, 0x00002a7c, 0x0000287c,
  57         0x0000267c, 0x0000247c, 0x0000227c, 0x0000207c,
  58         0x00001efc, 0x00001dfc, 0x00001cfc, 0x00001bfc,
  59         0x00001afc, 0x000019fc, 0x000018fc, 0x000017fc,
  60         0x000016fc, 0x000015fc, 0x000014fc, 0x000013fc,
  61         0x000012fc, 0x000011fc, 0x000010fc, 0x00000ffc,
  62         0x00000f3c, 0x00000ebc, 0x00000e3c, 0x00000dbc,
  63         0x00000d3c, 0x00000cbc, 0x00000c3c, 0x00000bbc,
  64         0x00000b3c, 0x00000abc, 0x00000a3c, 0x000009bc,
  65         0x0000093c, 0x000008bc, 0x0000083c, 0x000007bc,
  66         0x0000075c, 0x0000071c, 0x000006dc, 0x0000069c,
  67         0x0000065c, 0x0000061c, 0x000005dc, 0x0000059c,
  68         0x0000055c, 0x0000051c, 0x000004dc, 0x0000049c,
  69         0x0000045c, 0x0000041c, 0x000003dc, 0x0000039c,
  70         0x0000036c, 0x0000034c, 0x0000032c, 0x0000030c,
  71         0x000002ec, 0x000002cc, 0x000002ac, 0x0000028c,
  72         0x0000026c, 0x0000024c, 0x0000022c, 0x0000020c,
  73         0x000001ec, 0x000001cc, 0x000001ac, 0x0000018c,
  74         0x00000174, 0x00000164, 0x00000154, 0x00000144,
  75         0x00000134, 0x00000124, 0x00000114, 0x00000104,
  76         0x000000f4, 0x000000e4, 0x000000d4, 0x000000c4,
  77         0x000000b4, 0x000000a4, 0x00000094, 0x00000084,
  78         0x00000078, 0x00000070, 0x00000068, 0x00000060,
  79         0x00000058, 0x00000050, 0x00000048, 0x00000040,
  80         0x00000038, 0x00000030, 0x00000028, 0x00000020,
  81         0x00000018, 0x00000010, 0x00000008, 0x00000000
  82 };
  83
  84 /* alaw -> signed 16-bit */
  85 static signed int audio_alaw_to_s32[] =
  86 {
  87         0x000013fc, 0xffffec04, 0x00000144, 0xfffffebc,
  88         0x0000517c, 0xffffae84, 0x0000051c, 0xfffffae4,
  89         0x00000a3c, 0xfffff5c4, 0x00000048, 0xffffffb8,
  90         0x0000287c, 0xffffd784, 0x0000028c, 0xfffffd74,
  91         0x00001bfc, 0xffffe404, 0x000001cc, 0xfffffe34,
  92         0x0000717c, 0xffff8e84, 0x0000071c, 0xfffff8e4,
  93         0x00000e3c, 0xfffff1c4, 0x000000c4, 0xffffff3c,
  94         0x0000387c, 0xffffc784, 0x0000039c, 0xfffffc64,
  95         0x00000ffc, 0xfffff004, 0x00000104, 0xfffffefc,
  96         0x0000417c, 0xffffbe84, 0x0000041c, 0xfffffbe4,
  97         0x0000083c, 0xfffff7c4, 0x00000008, 0xfffffff8,
  98         0x0000207c, 0xffffdf84, 0x0000020c, 0xfffffdf4,
  99         0x000017fc, 0xffffe804, 0x0000018c, 0xfffffe74,
 100         0x0000617c, 0xffff9e84, 0x0000061c, 0xfffff9e4,
 101         0x00000c3c, 0xfffff3c4, 0x00000084, 0xffffff7c,
 102         0x0000307c, 0xffffcf84, 0x0000030c, 0xfffffcf4,
 103         0x000015fc, 0xffffea04, 0x00000164, 0xfffffe9c,
 104         0x0000597c, 0xffffa684, 0x0000059c, 0xfffffa64,
 105         0x00000b3c, 0xfffff4c4, 0x00000068, 0xffffff98,
 106         0x00002c7c, 0xffffd384, 0x000002cc, 0xfffffd34,
 107         0x00001dfc, 0xffffe204, 0x000001ec, 0xfffffe14,
 108         0x0000797c, 0xffff8684, 0x000007bc, 0xfffff844,
 109         0x00000f3c, 0xfffff0c4, 0x000000e4, 0xffffff1c,
 110         0x00003c7c, 0xffffc384, 0x000003dc, 0xfffffc24,
 111         0x000011fc, 0xffffee04, 0x00000124, 0xfffffedc,
 112         0x0000497c, 0xffffb684, 0x0000049c, 0xfffffb64,
 113         0x0000093c, 0xfffff6c4, 0x00000028, 0xffffffd8,
 114         0x0000247c, 0xffffdb84, 0x0000024c, 0xfffffdb4,
 115         0x000019fc, 0xffffe604, 0x000001ac, 0xfffffe54,
 116         0x0000697c, 0xffff9684, 0x0000069c, 0xfffff964,
 117         0x00000d3c, 0xfffff2c4, 0x000000a4, 0xffffff5c,
 118         0x0000347c, 0xffffcb84, 0x0000034c, 0xfffffcb4,
 119         0x000012fc, 0xffffed04, 0x00000134, 0xfffffecc,
 120         0x00004d7c, 0xffffb284, 0x000004dc, 0xfffffb24,
 121         0x000009bc, 0xfffff644, 0x00000038, 0xffffffc8,
 122         0x0000267c, 0xffffd984, 0x0000026c, 0xfffffd94,
 123         0x00001afc, 0xffffe504, 0x000001ac, 0xfffffe54,
 124         0x00006d7c, 0xffff9284, 0x000006dc, 0xfffff924,
 125         0x00000dbc, 0xfffff244, 0x000000b4, 0xffffff4c,
 126         0x0000367c, 0xffffc984, 0x0000036c, 0xfffffc94,
 127         0x00000f3c, 0xfffff0c4, 0x000000f4, 0xffffff0c,
 128         0x00003e7c, 0xffffc184, 0x000003dc, 0xfffffc24,
 129         0x000007bc, 0xfffff844, 0x00000008, 0xfffffff8,
 130         0x00001efc, 0xffffe104, 0x000001ec, 0xfffffe14,
 131         0x000016fc, 0xffffe904, 0x00000174, 0xfffffe8c,
 132         0x00005d7c, 0xffffa284, 0x000005dc, 0xfffffa24,
 133         0x00000bbc, 0xfffff444, 0x00000078, 0xffffff88,
 134         0x00002e7c, 0xffffd184, 0x000002ec, 0xfffffd14,
 135         0x000014fc, 0xffffeb04, 0x00000154, 0xfffffeac,
 136         0x0000557c, 0xffffaa84, 0x0000055c, 0xfffffaa4,
 137         0x00000abc, 0xfffff544, 0x00000058, 0xffffffa8,
 138         0x00002a7c, 0xffffd584, 0x000002ac, 0xfffffd54,
 139         0x00001cfc, 0xffffe304, 0x000001cc, 0xfffffe34,
 140         0x0000757c, 0xffff8a84, 0x0000075c, 0xfffff8a4,
 141         0x00000ebc, 0xfffff144, 0x000000d4, 0xffffff2c,
 142         0x00003a7c, 0xffffc584, 0x0000039c, 0xfffffc64,
 143         0x000010fc, 0xffffef04, 0x00000114, 0xfffffeec,
 144         0x0000457c, 0xffffba84, 0x0000045c, 0xfffffba4,
 145         0x000008bc, 0xfffff744, 0x00000018, 0xffffffe8,
 146         0x0000227c, 0xffffdd84, 0x0000022c, 0xfffffdd4,
 147         0x000018fc, 0xffffe704, 0x0000018c, 0xfffffe74,
 148         0x0000657c, 0xffff9a84, 0x0000065c, 0xfffff9a4,
 149         0x00000cbc, 0xfffff344, 0x00000094, 0xffffff6c,
 150         0x0000327c, 0xffffcd84, 0x0000032c, 0xfffffcd4
 151 };
 152
 153 /* signed 16-bit -> Xlaw */
 154 unsigned char audio_s16_to_law[65536];
 155
 156
 157 /* table is used to generate s16_to_alaw */
 158 static short audio_alaw_relations[] =
 159 {
 160         0x8684, 0x55, 0x8a84, 0xd5, 0x8e84, 0x15, 0x9284, 0x95,
 161         0x9684, 0x75, 0x9a84, 0xf5, 0x9e84, 0x35, 0xa284, 0xb5,
 162         0xa684, 0x45, 0xaa84, 0xc5, 0xae84, 0x05, 0xb284, 0x85,
 163         0xb684, 0x65, 0xba84, 0xe5, 0xbe84, 0x25, 0xc184, 0xa5,
 164         0xc384, 0x5d, 0xc584, 0xdd, 0xc784, 0x1d, 0xc984, 0x9d,
 165         0xcb84, 0x7d, 0xcd84, 0xfd, 0xcf84, 0x3d, 0xd184, 0xbd,
 166         0xd384, 0x4d, 0xd584, 0xcd, 0xd784, 0x0d, 0xd984, 0x8d,
 167         0xdb84, 0x6d, 0xdd84, 0xed, 0xdf84, 0x2d, 0xe104, 0xad,
 168         0xe204, 0x51, 0xe304, 0xd1, 0xe404, 0x11, 0xe504, 0x91,
 169         0xe604, 0x71, 0xe704, 0xf1, 0xe804, 0x31, 0xe904, 0xb1,
 170         0xea04, 0x41, 0xeb04, 0xc1, 0xec04, 0x01, 0xed04, 0x81,
 171         0xee04, 0x61, 0xef04, 0xe1, 0xf004, 0x21, 0xf0c4, 0x59,
 172         0xf0c4, 0xa1, 0xf144, 0xd9, 0xf1c4, 0x19, 0xf244, 0x99,
 173         0xf2c4, 0x79, 0xf344, 0xf9, 0xf3c4, 0x39, 0xf444, 0xb9,
 174         0xf4c4, 0x49, 0xf544, 0xc9, 0xf5c4, 0x09, 0xf644, 0x89,
 175         0xf6c4, 0x69, 0xf744, 0xe9, 0xf7c4, 0x29, 0xf844, 0x57,
 176         0xf844, 0xa9, 0xf8a4, 0xd7, 0xf8e4, 0x17, 0xf924, 0x97,
 177         0xf964, 0x77, 0xf9a4, 0xf7, 0xf9e4, 0x37, 0xfa24, 0xb7,
 178         0xfa64, 0x47, 0xfaa4, 0xc7, 0xfae4, 0x07, 0xfb24, 0x87,
 179         0xfb64, 0x67, 0xfba4, 0xe7, 0xfbe4, 0x27, 0xfc24, 0x5f,
 180         0xfc24, 0xa7, 0xfc64, 0x1f, 0xfc64, 0xdf, 0xfc94, 0x9f,
 181         0xfcb4, 0x7f, 0xfcd4, 0xff, 0xfcf4, 0x3f, 0xfd14, 0xbf,
 182         0xfd34, 0x4f, 0xfd54, 0xcf, 0xfd74, 0x0f, 0xfd94, 0x8f,
 183         0xfdb4, 0x6f, 0xfdd4, 0xef, 0xfdf4, 0x2f, 0xfe14, 0x53,
 184         0xfe14, 0xaf, 0xfe34, 0x13, 0xfe34, 0xd3, 0xfe54, 0x73,
 185         0xfe54, 0x93, 0xfe74, 0x33, 0xfe74, 0xf3, 0xfe8c, 0xb3,
 186         0xfe9c, 0x43, 0xfeac, 0xc3, 0xfebc, 0x03, 0xfecc, 0x83,
 187         0xfedc, 0x63, 0xfeec, 0xe3, 0xfefc, 0x23, 0xff0c, 0xa3,
 188         0xff1c, 0x5b, 0xff2c, 0xdb, 0xff3c, 0x1b, 0xff4c, 0x9b,
 189         0xff5c, 0x7b, 0xff6c, 0xfb, 0xff7c, 0x3b, 0xff88, 0xbb,
 190         0xff98, 0x4b, 0xffa8, 0xcb, 0xffb8, 0x0b, 0xffc8, 0x8b,
 191         0xffd8, 0x6b, 0xffe8, 0xeb, 0xfff8, 0x2b, 0xfff8, 0xab,
 192         0x0008, 0x2a, 0x0008, 0xaa, 0x0018, 0xea, 0x0028, 0x6a,
 193         0x0038, 0x8a, 0x0048, 0x0a, 0x0058, 0xca, 0x0068, 0x4a,
 194         0x0078, 0xba, 0x0084, 0x3a, 0x0094, 0xfa, 0x00a4, 0x7a,
 195         0x00b4, 0x9a, 0x00c4, 0x1a, 0x00d4, 0xda, 0x00e4, 0x5a,
 196         0x00f4, 0xa2, 0x0104, 0x22, 0x0114, 0xe2, 0x0124, 0x62,
 197         0x0134, 0x82, 0x0144, 0x02, 0x0154, 0xc2, 0x0164, 0x42,
 198         0x0174, 0xb2, 0x018c, 0x32, 0x018c, 0xf2, 0x01ac, 0x72,
 199         0x01ac, 0x92, 0x01cc, 0x12, 0x01cc, 0xd2, 0x01ec, 0x52,
 200         0x01ec, 0xae, 0x020c, 0x2e, 0x022c, 0xee, 0x024c, 0x6e,
 201         0x026c, 0x8e, 0x028c, 0x0e, 0x02ac, 0xce, 0x02cc, 0x4e,
 202         0x02ec, 0xbe, 0x030c, 0x3e, 0x032c, 0xfe, 0x034c, 0x7e,
 203         0x036c, 0x9e, 0x039c, 0x1e, 0x039c, 0xde, 0x03dc, 0x5e,
 204         0x03dc, 0xa6, 0x041c, 0x26, 0x045c, 0xe6, 0x049c, 0x66,
 205         0x04dc, 0x86, 0x051c, 0x06, 0x055c, 0xc6, 0x059c, 0x46,
 206         0x05dc, 0xb6, 0x061c, 0x36, 0x065c, 0xf6, 0x069c, 0x76,
 207         0x06dc, 0x96, 0x071c, 0x16, 0x075c, 0xd6, 0x07bc, 0x56,
 208         0x07bc, 0xa8, 0x083c, 0x28, 0x08bc, 0xe8, 0x093c, 0x68,
 209         0x09bc, 0x88, 0x0a3c, 0x08, 0x0abc, 0xc8, 0x0b3c, 0x48,
 210         0x0bbc, 0xb8, 0x0c3c, 0x38, 0x0cbc, 0xf8, 0x0d3c, 0x78,
 211         0x0dbc, 0x98, 0x0e3c, 0x18, 0x0ebc, 0xd8, 0x0f3c, 0x58,
 212         0x0f3c, 0xa0, 0x0ffc, 0x20, 0x10fc, 0xe0, 0x11fc, 0x60,
 213         0x12fc, 0x80, 0x13fc, 0x00, 0x14fc, 0xc0, 0x15fc, 0x40,
 214         0x16fc, 0xb0, 0x17fc, 0x30, 0x18fc, 0xf0, 0x19fc, 0x70,
 215         0x1afc, 0x90, 0x1bfc, 0x10, 0x1cfc, 0xd0, 0x1dfc, 0x50,
 216         0x1efc, 0xac, 0x207c, 0x2c, 0x227c, 0xec, 0x247c, 0x6c,
 217         0x267c, 0x8c, 0x287c, 0x0c, 0x2a7c, 0xcc, 0x2c7c, 0x4c,
 218         0x2e7c, 0xbc, 0x307c, 0x3c, 0x327c, 0xfc, 0x347c, 0x7c,
 219         0x367c, 0x9c, 0x387c, 0x1c, 0x3a7c, 0xdc, 0x3c7c, 0x5c,
 220         0x3e7c, 0xa4, 0x417c, 0x24, 0x457c, 0xe4, 0x497c, 0x64,
 221         0x4d7c, 0x84, 0x517c, 0x04, 0x557c, 0xc4, 0x597c, 0x44,
 222         0x5d7c, 0xb4, 0x617c, 0x34, 0x657c, 0xf4, 0x697c, 0x74,
 223         0x6d7c, 0x94, 0x717c, 0x14, 0x757c, 0xd4, 0x797c, 0x54
 224 };
 225
 226 /* generate tables for conversion of s16 to alaw/ulaw
 227  */
 228 void generate_tables(char law)
 229 {
 230         int i, j;
 231
 232         if (law == 'a') {
 233                 silence = 0x2a;
 234                 audio_law_to_s32=audio_alaw_to_s32;
 235                 /* generating alaw-table */
 236                 i = j = 0;
 237                 while(i < 65536) {
 238                         if (i-32768 > audio_alaw_relations[j<<1])
 239                                 j++;
 240                         if (j>255)
 241                                 j=255;
 242                         audio_s16_to_law[(i-32768) & 0xffff]
 243                                  = audio_alaw_relations[(j<<1)|1];
 244                         i++;
 245                 }
 246         } else {
 247                 silence = 0xff;
 248                 audio_law_to_s32=audio_ulaw_to_s32;
 249                 /* generating ulaw-table */
 250                 i = j = 0;
 251                 while(i < 32768) {
 252                         if (i-32768 > audio_ulaw_to_s32[j])
 253                                 j++;
 254                         audio_s16_to_law[(i-32768) & 0xffff] = j;
 255                         i++;
 256                 }
 257                 j = 255;
 258                 while(i < 65536) {
 259                         if (i-0x32768 > audio_ulaw_to_s32[j])
 260                                 j--;
 261                         audio_s16_to_law[(i-32768) & 0xffff] = j;
 262                         i++;
 263                 }
 264         }
 265 }
 266
 267