7 |
* Returns a field of bits that indicates non zero ac blocks |
* Returns a field of bits that indicates non zero ac blocks |
8 |
* for this macro block |
* for this macro block |
9 |
*/ |
*/ |
10 |
|
|
11 |
|
/* naive C */ |
12 |
uint32_t |
uint32_t |
13 |
calc_cbp_c(const int16_t codes[6 * 64]) |
calc_cbp_plain(const int16_t codes[6 * 64]) |
14 |
{ |
{ |
15 |
uint32_t i, j; |
int i, j; |
16 |
uint32_t cbp = 0; |
uint32_t cbp = 0; |
17 |
|
|
18 |
for (i = 0; i < 6; i++) { |
for (i = 0; i < 6; i++) { |
19 |
for (j = 1; j < 61; j += 4) { |
for (j=1; j<64;j++) { |
20 |
if (codes[i * 64 + j] | codes[i * 64 + j + 1] | |
if (codes[64*i+j]) { |
|
codes[i * 64 + j + 2] | codes[i * 64 + j + 3]) { |
|
21 |
cbp |= 1 << (5 - i); |
cbp |= 1 << (5 - i); |
22 |
break; |
break; |
23 |
} |
} |
24 |
} |
} |
25 |
|
} |
26 |
|
return cbp; |
27 |
|
} |
28 |
|
|
29 |
if (codes[i * 64 + j] | codes[i * 64 + j + 1] | codes[i * 64 + j + 2]) |
/* optimized C */ |
30 |
cbp |= 1 << (5 - i); |
uint32_t |
31 |
|
calc_cbp_c(const int16_t codes[6 * 64]) |
32 |
|
{ |
33 |
|
unsigned int i=6; |
34 |
|
uint32_t cbp = 0; |
35 |
|
|
36 |
|
/* uses fixed relation: 4*codes = 1*codes64 */ |
37 |
|
/* if prototype is changed (e.g. from int16_t to something like int32) this routine |
38 |
|
has to be changed! */ |
39 |
|
|
40 |
|
do { |
41 |
|
uint64_t *codes64 = (uint64_t*)codes; /* the compiler doesn't really make this */ |
42 |
|
uint32_t *codes32 = (uint32_t*)codes; /* variables, just "addressing modes" */ |
43 |
|
|
44 |
|
cbp += cbp; |
45 |
|
if (codes[1] || codes32[1]) { |
46 |
|
cbp++; |
47 |
|
} |
48 |
|
else if (codes64[1] | codes64[2] | codes64[3]) { |
49 |
|
cbp++; |
50 |
} |
} |
51 |
|
else if (codes64[4] | codes64[5] | codes64[6] | codes64[7]) { |
52 |
|
cbp++; |
53 |
|
} |
54 |
|
else if (codes64[8] | codes64[9] | codes64[10] | codes64[11]) { |
55 |
|
cbp++; |
56 |
|
} |
57 |
|
else if (codes64[12] | codes64[13] | codes64[14] | codes64[15]) { |
58 |
|
cbp++; |
59 |
|
} |
60 |
|
codes += 64; |
61 |
|
i--; |
62 |
|
} while (i != 0); |
63 |
|
|
64 |
return cbp; |
return cbp; |
65 |
|
} |
66 |
|
|
67 |
|
|
68 |
|
|
69 |
|
|
70 |
|
/* older code maybe better on some plattforms? */ |
71 |
|
#if (0==1) |
72 |
|
for (i = 5; i >= 0; i--) { |
73 |
|
if (codes[1] | codes[2] | codes[3]) |
74 |
|
cbp |= 1 << i; |
75 |
|
else { |
76 |
|
for (j = 4; j <= 56; j+=4) /* [60],[61],[62],[63] are last */ |
77 |
|
if (codes[j] | codes[j+1] | codes[j+2] | codes[j+3]) { |
78 |
|
cbp |= 1 << i; |
79 |
|
break; |
80 |
|
} |
81 |
} |
} |
82 |
|
codes += 64; |
83 |
|
} |
84 |
|
|
85 |
|
return cbp; |
86 |
|
#endif |