swr-test: Use randomized collision free hypercube corner enumeration to select tests.

This way the user can specify how many or few tests should run while
still providing good coverage over the whole parameter set.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswresample/swresample_test.c

@@ -132,6 +132,10 @@ static void setup_array(uint8_t *out[SWR_CH_MAX], uint8_t *in, enum AVSampleForm
     }
 }
 
+static int cmp(const int *a, const int *b){
+    return *a - *b;
+}
+
 int main(int argc, char **argv){
     int in_sample_rate, out_sample_rate, ch ,i, in_ch_layout_index, out_ch_layout_index, osr, flush_count;
     int in_sample_fmt_index, out_sample_fmt_index;
@@ -145,24 +149,50 @@ int main(int argc, char **argv){
     uint8_t *amid[SWR_CH_MAX];
     int flush_i=0;
     int mode = 0;
+    int max_tests = FF_ARRAY_ELEMS(rates) * FF_ARRAY_ELEMS(layouts) * FF_ARRAY_ELEMS(formats) * FF_ARRAY_ELEMS(layouts) * FF_ARRAY_ELEMS(formats);
+    int num_tests = 10000;
+    uint32_t seed = 0;
+    int remaining_tests[max_tests];
+    int test;
 
     struct SwrContext * forw_ctx= NULL;
     struct SwrContext *backw_ctx= NULL;
 
+    if (argc > 1) {
+        if (!strcmp(argv[1], "-h")) {
+            av_log(NULL, AV_LOG_INFO, "Usage: swresample-test [<num_tests>]\n"
+                   "Default is %d\n", num_tests);
+            return 0;
+        }
+        num_tests = strtol(argv[1], NULL, 0);
+        if(num_tests<= 0 || num_tests>max_tests)
+            num_tests = max_tests;
+    }
+
+    for(i=0; i<max_tests; i++)
+        remaining_tests[i] = i;
+
+    for(test=0; test<num_tests; test++){
+        unsigned r;
+        seed = seed * 1664525 + 1013904223;
+        r = (seed * (uint64_t)(max_tests - test)) >>32;
+        FFSWAP(int, remaining_tests[r], remaining_tests[max_tests - test - 1]);
+    }
+    qsort(remaining_tests + max_tests - num_tests, num_tests, sizeof(remaining_tests[0]), cmp);
     in_sample_rate=16000;
-    for(osr=0; osr<FF_ARRAY_ELEMS(rates); osr++){
-        out_sample_rate= rates[osr];
-        for(in_sample_fmt_index=0; in_sample_fmt_index<FF_ARRAY_ELEMS(formats); in_sample_fmt_index++){
-            in_sample_fmt = formats[in_sample_fmt_index];
-            for(out_sample_fmt_index=0; out_sample_fmt_index<FF_ARRAY_ELEMS(formats); out_sample_fmt_index++){
-                out_sample_fmt = formats[out_sample_fmt_index];
-                for(in_ch_layout_index=0; in_ch_layout_index < FF_ARRAY_ELEMS(layouts); in_ch_layout_index++){
+    for(test=0; test<num_tests; test++){
+        unsigned vector= remaining_tests[max_tests - test - 1];
+
+        in_ch_layout    = layouts[vector % FF_ARRAY_ELEMS(layouts)]; vector /= FF_ARRAY_ELEMS(layouts);
+        out_ch_layout   = layouts[vector % FF_ARRAY_ELEMS(layouts)]; vector /= FF_ARRAY_ELEMS(layouts);
+        in_sample_fmt   = formats[vector % FF_ARRAY_ELEMS(formats)]; vector /= FF_ARRAY_ELEMS(formats);
+        out_sample_fmt  = formats[vector % FF_ARRAY_ELEMS(formats)]; vector /= FF_ARRAY_ELEMS(formats);
+        out_sample_rate = rates  [vector % FF_ARRAY_ELEMS(rates  )]; vector /= FF_ARRAY_ELEMS(rates);
+        av_assert0(!vector);
+
                     int in_ch_count;
-                    in_ch_layout= layouts[in_ch_layout_index];
                     in_ch_count= av_get_channel_layout_nb_channels(in_ch_layout);
-                    for(out_ch_layout_index=0; out_ch_layout_index < FF_ARRAY_ELEMS(layouts); out_ch_layout_index++){
                         int out_count, mid_count, out_ch_count;
-                        out_ch_layout= layouts[out_ch_layout_index];
                         out_ch_count= av_get_channel_layout_nb_channels(out_ch_layout);
                         fprintf(stderr, "ch %d->%d, rate:%5d->%5d, fmt:%s->%s\n",
                                in_ch_count, out_ch_count,
@@ -271,10 +301,6 @@ int main(int argc, char **argv){
 
 
                         fprintf(stderr, "\n");
-                    }
-                }
-            }
-        }
     }
 
     return 0;