Statistics
| Branch: | Revision:

ffmpeg / libavcodec / dct-test.c @ d771bcae

History | View | Annotate | Download (2.63 KB)

1 de6d9b64 Fabrice Bellard
/* DCT test. (c) 2001 Gerard Lantau. 
2
   Started from sample code by Juan J. Sierralta P.
3
*/
4
#include <stdlib.h>
5
#include <stdio.h>
6
#include <string.h>
7
#include <sys/time.h>
8
#include <unistd.h>
9
10
#include "dsputil.h"
11
12
extern void fdct(DCTELEM *block);
13
extern void init_fdct();
14
15
#define AANSCALE_BITS 12
16
static const unsigned short aanscales[64] = {
17
    /* precomputed values scaled up by 14 bits */
18
    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
19
    22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
20
    21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
21
    19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
22
    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
23
    12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
24
    8867, 12299, 11585, 10426,  8867,  6967,  4799,  2446,
25
    4520,  6270,  5906,  5315,  4520,  3552,  2446,  1247
26
};
27
28
INT64 gettime(void)
29
{
30
    struct timeval tv;
31
    gettimeofday(&tv,NULL);
32
    return (INT64)tv.tv_sec * 1000000 + tv.tv_usec;
33
}
34
35
#define NB_ITS 20000
36
#define NB_ITS_SPEED 50000
37
38
void dct_error(const char *name,
39
               void (*fdct_func)(DCTELEM *block))
40
{
41
    int it, i, scale;
42
    DCTELEM block[64], block1[64];
43
    int err_inf, v;
44
    INT64 err2, ti, ti1, it1;
45
46
    srandom(0);
47
48
    err_inf = 0;
49
    err2 = 0;
50
    for(it=0;it<NB_ITS;it++) {
51
        for(i=0;i<64;i++) 
52
            block1[i] = random() % 256;
53
        memcpy(block, block1, sizeof(DCTELEM) * 64);
54
        
55
        fdct_func(block);
56
        if (fdct_func == jpeg_fdct_ifast) {
57
            for(i=0; i<64; i++) {
58
                scale = (1 << (AANSCALE_BITS + 11)) / aanscales[i];
59
                block[i] = (block[i] * scale) >> AANSCALE_BITS;
60
            }
61
        }
62
63
        fdct(block1);
64
65
        for(i=0;i<64;i++) {
66
            v = abs(block[i] - block1[i]);
67
            if (v > err_inf)
68
                err_inf = v;
69
            err2 += v * v;
70
        }
71
    }
72
    printf("DCT %s: err_inf=%d err2=%0.2f\n", 
73
           name, err_inf, (double)err2 / NB_ITS / 64.0);
74
75
    /* speed test */
76
    for(i=0;i<64;i++) 
77
        block1[i] = 255 - 63 + i;
78
79
    ti = gettime();
80
    it1 = 0;
81
    do {
82
        for(it=0;it<NB_ITS_SPEED;it++) {
83
            memcpy(block, block1, sizeof(DCTELEM) * 64);
84
            fdct_func(block);
85
        }
86
        it1 += NB_ITS_SPEED;
87
        ti1 = gettime() - ti;
88
    } while (ti1 < 1000000);
89
90
    printf("DCT %s: %0.1f kdct/s\n", 
91
           name, (double)it1 * 1000.0 / (double)ti1);
92
}
93
94
int main(int argc, char **argv)
95
{
96
    init_fdct();
97
    
98
    printf("ffmpeg DCT test\n");
99
100
    dct_error("REF", fdct); /* only to verify code ! */
101
    dct_error("AAN", jpeg_fdct_ifast);
102
    dct_error("MMX", fdct_mmx);
103
    return 0;
104
}
105