33 static const uint16_t exp2a[]=
35 0, 1435, 2901, 4400, 5931, 7496, 9096, 10730,
36 12400, 14106, 15850, 17632, 19454, 21315, 23216, 25160,
37 27146, 29175, 31249, 33368, 35534, 37747, 40009, 42320,
38 44682, 47095, 49562, 52082, 54657, 57289, 59979, 62727,
41 static const uint16_t exp2b[]=
43 3, 712, 1424, 2134, 2845, 3557, 4270, 4982,
44 5696, 6409, 7124, 7839, 8554, 9270, 9986, 10704,
45 11421, 12138, 12857, 13576, 14295, 15014, 15734, 16455,
46 17176, 17898, 18620, 19343, 20066, 20790, 21514, 22238,
51 unsigned int result= exp2a[power>>10] + 0x10000;
55 result= (result<<3) + ((result*exp2b[(power>>5)&31])>>17);
56 return result + ((result*(power&31)*89)>>22);
68 0, 1455, 2866, 4236, 5568, 6863, 8124, 9352,
69 10549, 11716, 12855, 13967, 15054, 16117, 17156, 18172,
70 19167, 20142, 21097, 22033, 22951, 23852, 24735, 25603,
71 26455, 27291, 28113, 28922, 29716, 30497, 31266, 32023, 32767,
73 4, 1459, 2870, 4240, 5572, 6867, 8127, 9355,
74 10552, 11719, 12858, 13971, 15057, 16120, 17158, 18175,
75 19170, 20145, 21100, 22036, 22954, 23854, 24738, 25605,
76 26457, 27294, 28116, 28924, 29719, 30500, 31269, 32025, 32769,
88 value <<= (31 - power_int);
91 frac_x0 = (value & 0x7c000000) >> 26;
92 frac_dx = (value & 0x03fff800) >> 11;
97 return (power_int << 15) +
value;
105 for (i = 0; i <
length; i++)
106 sum +=
MUL16(a[i], b[i]);
void ff_celp_math_init_mips(CELPMContext *c)
float ff_dot_productf(const float *a, const float *b, int length)
Return the dot product.
float(* dot_productf)(const float *a, const float *b, int length)
Return the dot product.
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
int ff_exp2(uint16_t power)
fixed-point implementation of exp2(x) in [0; 1] domain.
static const uint16_t tab_log2[33]
Table used to compute log2(x)
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
GLsizei GLboolean const GLfloat * value
simple assert() macros that are a bit more flexible than ISO C assert().
int64_t ff_dot_product(const int16_t *a, const int16_t *b, int length)
Calculate the dot product of 2 int16_t vectors.
int ff_log2_q15(uint32_t value)
Calculate log2(x).
Libavcodec external API header.
void ff_celp_math_init(CELPMContext *c)
Initialize CELPMContext.
common internal and external API header
and forward the result(frame or status change) to the corresponding input.If nothing is possible