lavc: Use av_gettime_relative()

Whenever av_gettime() is used to measure relative period of time,
av_gettime_relative() is prefered as it guarantee monotonic time
on supported platforms.
Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/dct-test.c

@@ -348,7 +348,7 @@ static int dct_error(const struct algo *dct, int test, int is_idct, int speed, c
     init_block(block, test, is_idct, &prng, vals);
     permute(block1, block, dct->format);
 
-    ti = av_gettime();
+    ti = av_gettime_relative();
     it1 = 0;
     do {
         for (it = 0; it < NB_ITS_SPEED; it++) {
@@ -357,7 +357,7 @@ static int dct_error(const struct algo *dct, int test, int is_idct, int speed, c
         }
         emms_c();
         it1 += NB_ITS_SPEED;
-        ti1 = av_gettime() - ti;
+        ti1 = av_gettime_relative() - ti;
     } while (ti1 < 1000000);
 
     printf("%s %s: %0.1f kdct/s\n", is_idct ? "IDCT" : "DCT", dct->name,
@@ -508,7 +508,7 @@ static void idct248_error(const char *name,
     if (!speed)
         return;
 
-    ti = av_gettime();
+    ti = av_gettime_relative();
     it1 = 0;
     do {
         for (it = 0; it < NB_ITS_SPEED; it++) {
@@ -518,7 +518,7 @@ static void idct248_error(const char *name,
         }
         emms_c();
         it1 += NB_ITS_SPEED;
-        ti1 = av_gettime() - ti;
+        ti1 = av_gettime_relative() - ti;
     } while (ti1 < 1000000);
 
     printf("%s %s: %0.1f kdct/s\n", 1 ? "IDCT248" : "DCT248", name,

libavcodec/fft-test.c

@@ -438,7 +438,7 @@ int main(int argc, char **argv)
         /* we measure during about 1 seconds */
         nb_its = 1;
         for(;;) {
-            time_start = av_gettime();
+            time_start = av_gettime_relative();
             for (it = 0; it < nb_its; it++) {
                 switch (transform) {
                 case TRANSFORM_MDCT:
@@ -464,7 +464,7 @@ int main(int argc, char **argv)
 #endif
                 }
             }
-            duration = av_gettime() - time_start;
+            duration = av_gettime_relative() - time_start;
             if (duration >= 1000000)
                 break;
             nb_its *= 2;

libavcodec/motion-test.c

@@ -91,7 +91,7 @@ static void test_motion(const char *name,
     emms_c();
 
     /* speed test */
-    ti = av_gettime();
+    ti = av_gettime_relative();
     d1 = 0;
     for(it=0;it<NB_ITS;it++) {
         for(y=0;y<HEIGHT-17;y++) {
@@ -103,7 +103,7 @@ static void test_motion(const char *name,
     }
     emms_c();
     dummy = d1; /* avoid optimization */
-    ti = av_gettime() - ti;
+    ti = av_gettime_relative() - ti;
 
     printf("  %0.0f kop/s\n",
            (double)NB_ITS * (WIDTH - 16) * (HEIGHT - 16) /