在网上看到很多ADPCM的C语言算法,用的都是那两张表,这索引表具体怎么来的就不详细探究了,小弟就想知道这玩意怎么用在具体例子里面。
比如两个连续的16bit PCM音频数据为810A和9F42,请问压缩的过程是怎么样的?
int index_adjust[8] = {-1,-1,-1,-1,2,4,6,8};
int step_table[89] = { 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 }; |