Move Limiter implementation to separate files.

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

src/Makefile.am

@@ -3,7 +3,8 @@ bin_PROGRAMS = audiowmark
 COMMON_SRC = utils.hh utils.cc convcode.hh convcode.cc random.hh random.cc wavdata.cc wavdata.hh \
 	     audiostream.cc audiostream.hh sfinputstream.cc sfinputstream.hh stdoutwavoutputstream.cc stdoutwavoutputstream.hh \
 	     sfoutputstream.cc sfoutputstream.hh rawinputstream.cc rawinputstream.hh rawoutputstream.cc rawoutputstream.hh \
-	     rawconverter.cc rawconverter.hh mp3inputstream.cc mp3inputstream.hh wmcommon.cc wmcommon.hh fft.cc fft.hh
+	     rawconverter.cc rawconverter.hh mp3inputstream.cc mp3inputstream.hh wmcommon.cc wmcommon.hh fft.cc fft.hh \
+	     limiter.cc limiter.hh
 COMMON_LIBS = $(SNDFILE_LIBS) $(FFTW_LIBS) $(LIBGCRYPT_LIBS) $(LIBMPG123_LIBS)
 
 audiowmark_SOURCES = audiowmark.cc wmget.cc wmadd.cc $(COMMON_SRC)

src/limiter.cc

+#include "limiter.hh"
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+
+using std::vector;
+using std::max;
+
+Limiter::Limiter (int sample_rate)
+{
+  look_ahead = sample_rate * 0.005;
+  assert (look_ahead >= 1);
+
+  decay_coeff = exp (log (0.5) / (sample_rate * 0.05));
+}
+
+vector<float>
+Limiter::process (const vector<float>& samples)
+{
+  for (size_t i = 0; i < samples.size(); i++)
+    {
+      buffer.push_back (samples[i]);
+      max_buffer.push_back (1);
+    }
+  for (size_t i = 0; i < buffer.size(); i++)
+    {
+      if (fabs (buffer[i]) > 1)
+        {
+          for (uint j = 0; j < look_ahead; j++)
+            {
+              if (int (i) - int (j) > 0)
+                {
+                  double alpha = double (j) / look_ahead;
+                  max_buffer[i - j] = max<float> (max_buffer[i - j], fabs (buffer[i]) * (1 - alpha) + 1 * alpha);
+                }
+            }
+        }
+    }
+
+  vector<float> out;
+  if (buffer.size() > look_ahead)
+    {
+      size_t todo = buffer.size() - look_ahead;
+      for (size_t i = 0; i < todo; i++)
+        {
+          maximum = maximum * decay_coeff + max_buffer[i] * (1 - decay_coeff);
+          if (maximum < max_buffer[i])
+            maximum = max_buffer[i];
+
+          out.push_back (buffer[i] / maximum);
+          //printf ("%f %f\n", buffer[i], out.back());
+        }
+
+      buffer.erase (buffer.begin(), buffer.begin() + todo);
+      max_buffer.erase (max_buffer.begin(), max_buffer.begin() + todo);
+    }
+  return out;
+}

src/limiter.hh

+#ifndef AUDIOWMARK_LIMITER_HH
+#define AUDIOWMARK_LIMITER_HH
+
+#include <vector>
+#include <sys/types.h>
+
+class Limiter
+{
+  float maximum       = 1;
+  double decay_coeff  = 1;
+  uint look_ahead     = 0;
+
+  std::vector<float> max_buffer;
+  std::vector<float> buffer;
+public:
+  Limiter (int sample_rate);
+
+  std::vector<float> process (const std::vector<float>& samples);
+};
+
+#endif /* AUDIOWMARK_LIMITER_HH */

src/testlimiter.cc

@@ -5,87 +5,29 @@
 #include <math.h>
 
 #include "sfinputstream.hh"
-#include "stdoutwavoutputstream.hh"
+#include "sfoutputstream.hh"
 #include "utils.hh"
+#include "limiter.hh"
 
 using std::string;
 using std::vector;
 using std::max;
 using std::min;
 
-class Limiter
-{
-  float mx = 1;
-  double decay_coeff;
-  uint look_ahead = 0;
-  vector<float> max_buffer;
-  vector<float> buffer;
-public:
-  Limiter (int sample_rate)
-  {
-    look_ahead = sample_rate * 0.005;
-    assert (look_ahead >= 1);
-
-    decay_coeff = exp (log (0.5) / (sample_rate * 0.05));
-  }
-  vector<float>
-  process (const vector<float>& samples)
-  {
-    for (size_t i = 0; i < samples.size(); i++)
-      {
-        buffer.push_back (samples[i]);
-        max_buffer.push_back (1);
-      }
-    for (size_t i = 0; i < buffer.size(); i++)
-      {
-        if (fabs (buffer[i]) > 1)
-          {
-            for (uint j = 0; j < look_ahead; j++)
-              {
-                if (int (i) - int (j) > 0)
-                  {
-                    double alpha = double (j) / look_ahead;
-                    max_buffer[i - j] = max<float> (max_buffer[i - j], fabs (buffer[i]) * (1 - alpha) + 1 * alpha);
-                  }
-              }
-          }
-      }
-
-    vector<float> out;
-    if (buffer.size() > look_ahead)
-      {
-        size_t todo = buffer.size() - look_ahead;
-        for (size_t i = 0; i < todo; i++)
-          {
-            mx = mx * decay_coeff + max_buffer[i] * (1 - decay_coeff);
-            if (mx < max_buffer[i])
-              mx = max_buffer[i];
-
-            out.push_back (buffer[i] / mx);
-            printf ("%f %f\n", buffer[i], out.back());
-          }
-
-        buffer.erase (buffer.begin(), buffer.begin() + todo);
-        max_buffer.erase (max_buffer.begin(), max_buffer.begin() + todo);
-      }
-    return out;
-  }
-};
 
 int
 main (int argc, char **argv)
 {
   SFInputStream in;
-  StdoutWavOutputStream out;
+  SFOutputStream out;
 
-  std::string filename = (argc >= 2) ? argv[1] : "-";
-  Error err = in.open (filename.c_str());
+  Error err = in.open (argv[1]);
   if (err)
     {
       fprintf (stderr, "teststream: open input failed: %s\n", err.message());
       return 1;
     }
-  err = out.open (in.n_channels(), in.sample_rate(), 16, in.n_frames());
+  err = out.open (argv[2], in.n_channels(), in.sample_rate(), 16, in.n_frames());
   if (err)
     {
       fprintf (stderr, "teststream: open output failed: %s\n", err.message());
@@ -99,7 +41,7 @@ main (int argc, char **argv)
       for (auto& s: samples)
         s *= 1.1;
       samples = limiter.process (samples);
-      //out.write_frames (samples);
+      out.write_frames (samples);
     }
   while (samples.size());
 }