Add limiter performance test: testlimiter perf.

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/testlimiter.cc

@@ -3,6 +3,8 @@
 #include <sndfile.h>
 #include <assert.h>
 #include <math.h>
+#include <string.h>
+#include <sys/time.h>
 
 #include "sfinputstream.hh"
 #include "sfoutputstream.hh"
@@ -14,10 +16,44 @@ using std::vector;
 using std::max;
 using std::min;
 
+static double
+gettime()
+{
+  timeval tv;
+  gettimeofday (&tv, 0);
+
+  return tv.tv_sec + tv.tv_usec / 1000000.0;
+}
+
+int
+perf()
+{
+  Limiter limiter (2, 44100);
+
+  limiter.set_attack (5);
+  limiter.set_release (50);
+  limiter.set_ceiling (1.0);
+
+  vector<float> samples (2 * 1024);
+
+  int n_frames = 0;
+  double start = gettime();
+  for (int i = 0; i < 10000; i++)
+    {
+      n_frames += samples.size() / 2;
+      vector<float> out_samples = limiter.process (samples);
+    }
+  double end = gettime();
+  printf ("%f ns/frame\n", (end - start) * 1000 * 1000 * 1000 / n_frames);
+  return 0;
+}
 
 int
 main (int argc, char **argv)
 {
+  if (argc == 2 && strcmp (argv[1], "perf") == 0)
+    return perf();
+
   SFInputStream in;
   SFOutputStream out;