1 files changed, 105 insertions, 0 deletions
diff --git a/libavcodec/dct-test.c b/libavcodec/dct-test.c
new file mode 100644
index 0000000000..1da23a1d8e
--- /dev/null
+++ b/libavcodec/dct-test.c
@@ -0,0 +1,105 @@
+/* DCT test. (c) 2001 Gerard Lantau. 
+   Started from sample code by Juan J. Sierralta P.
+*/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "dsputil.h"
+
+extern void fdct(DCTELEM *block);
+extern void init_fdct();
+
+#define AANSCALE_BITS 12
+static const unsigned short aanscales[64] = {
+    /* precomputed values scaled up by 14 bits */
+    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+    22725, 31521, 29692, 26722, 22725, 17855, 12299,  6270,
+    21407, 29692, 27969, 25172, 21407, 16819, 11585,  5906,
+    19266, 26722, 25172, 22654, 19266, 15137, 10426,  5315,
+    16384, 22725, 21407, 19266, 16384, 12873,  8867,  4520,
+    12873, 17855, 16819, 15137, 12873, 10114,  6967,  3552,
+    8867, 12299, 11585, 10426,  8867,  6967,  4799,  2446,
+    4520,  6270,  5906,  5315,  4520,  3552,  2446,  1247
+};
+
+INT64 gettime(void)
+{
+    struct timeval tv;
+    gettimeofday(&tv,NULL);
+    return (INT64)tv.tv_sec * 1000000 + tv.tv_usec;
+}
+
+#define NB_ITS 20000
+#define NB_ITS_SPEED 50000
+
+void dct_error(const char *name,
+               void (*fdct_func)(DCTELEM *block))
+{
+    int it, i, scale;
+    DCTELEM block[64], block1[64];
+    int err_inf, v;
+    INT64 err2, ti, ti1, it1;
+
+    srandom(0);
+
+    err_inf = 0;
+    err2 = 0;
+    for(it=0;it<NB_ITS;it++) {
+        for(i=0;i<64;i++) 
+            block1[i] = random() % 256;
+        memcpy(block, block1, sizeof(DCTELEM) * 64);
+        
+        fdct_func(block);
+        if (fdct_func == jpeg_fdct_ifast) {
+            for(i=0; i<64; i++) {
+                scale = (1 << (AANSCALE_BITS + 11)) / aanscales[i];
+                block[i] = (block[i] * scale) >> AANSCALE_BITS;
+            }
+        }
+
+        fdct(block1);
+
+        for(i=0;i<64;i++) {
+            v = abs(block[i] - block1[i]);
+            if (v > err_inf)
+                err_inf = v;
+            err2 += v * v;
+        }
+    }
+    printf("DCT %s: err_inf=%d err2=%0.2f\n", 
+           name, err_inf, (double)err2 / NB_ITS / 64.0);
+
+    /* speed test */
+    for(i=0;i<64;i++) 
+        block1[i] = 255 - 63 + i;
+
+    ti = gettime();
+    it1 = 0;
+    do {
+        for(it=0;it<NB_ITS_SPEED;it++) {
+            memcpy(block, block1, sizeof(DCTELEM) * 64);
+            fdct_func(block);
+        }
+        it1 += NB_ITS_SPEED;
+        ti1 = gettime() - ti;
+    } while (ti1 < 1000000);
+
+    printf("DCT %s: %0.1f kdct/s\n", 
+           name, (double)it1 * 1000.0 / (double)ti1);
+}
+
+int main(int argc, char **argv)
+{
+    init_fdct();
+    
+    printf("ffmpeg DCT test\n");
+
+    dct_error("REF", fdct); /* only to verify code ! */
+    dct_error("AAN", jpeg_fdct_ifast);
+    dct_error("MMX", fdct_mmx);
+    return 0;
+}
+