Citation:
typedef unsigned char alaw8;
typedef signed short pcm16;
pcm16 alawTable[] =
{688, -688, 43, -43, 2752, -2752, 172, -172,
344, -344, 11, -11, 1376, -1376, 86, -86,
944, -944, 59, -59, 3776, -3776, 236, -236,
472, -472, 27, -27, 1888, -1888, 118, -118,
560, -560, 35, -35, 2240, -2240, 140, -140,
280, -280, 3, -3, 1120, -1120, 70, -70,
816, -816, 51, -51, 3264, -3264, 204, -204,
408, -408, 19, -19, 1632, -1632, 102, -102,
752, -752, 47, -47, 3008, -3008, 188, -188,
376, -376, 15, -15, 1504, -1504, 94, -94,
1008, -1008, 63, -63, 4032, -4032, 252, -252,
504, -504, 31, -31, 2016, -2016, 126, -126,
624, -624, 39, -39, 2496, -2496, 156, -156,
312, -312, 7, -7, 1248, -1248, 78, -78,
880, -880, 55, -55, 3520, -3520, 220, -220,
440, -440, 23, -23, 1760, -1760, 110, -110,
656, -656, 41, -41, 2624, -2624, 164, -164,
328, -328, 9, -9, 1312, -1312, 82, -82,
912, -912, 57, -57, 3648, -3648, 228, -228,
456, -456, 25, -25, 1824, -1824, 114, -114,
528, -528, 33, -33, 2112, -2112, 132, -132,
264, -264, 1, -1, 1056, -1056, 66, -66,
784, -784, 49, -49, 3136, -3136, 196, -196,
392, -392, 17, -17, 1568, -1568, 98, -98,
720, -720, 45, -45, 2880, -2880, 180, -180,
360, -360, 13, -13, 1440, -1440, 90, -90,
976, -976, 61, -61, 3904, -3904, 244, -244,
488, -488, 29, -29, 1952, -1952, 122, -122,
592, -592, 37, -37, 2368, -2368, 148, -148,
296, -296, 5, -5, 1184, -1184, 74, -74,
848, -848, 53, -53, 3392, -3392, 212, -212,
424, -424, 21, -21, 1696, -1696, 106, -106};
alaw8 reverseByte[256] = {
0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0,
0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8,
0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4,
0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2,
0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA,
0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6,
0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE,
0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1,
0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9,
0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED,
0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3,
0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB,
0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7,
0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF,
0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF,
};
static pcm16 alaw2linear(alaw8 a_val){
a_val = reverseByte[a_val & 0xFF]; // isdn alaw est inverse
return alawTable[a_val];
}
