Integrate Limiter into main watermarking loop.

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

src/wmadd.cc

@@ -6,6 +6,7 @@
 #include "wmcommon.hh"
 #include "fft.hh"
 #include "convcode.hh"
+#include "limiter.hh"
 #include "sfinputstream.hh"
 #include "sfoutputstream.hh"
 #include "mp3inputstream.hh"
@@ -643,6 +644,11 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
   if (!wm_resampler.init_ok())
     return 1;
 
+  Limiter limiter (in_stream->sample_rate());
+  limiter.set_attack (Params::limiter_attack_ms);
+  limiter.set_release (Params::limiter_release_ms);
+  limiter.set_ceiling (Params::limiter_ceiling);
+
   /* for signal to noise ratio */
   double snr_delta_power = 0;
   double snr_signal_power = 0;
@@ -687,6 +693,8 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
       for (size_t i = 0; i < samples.size(); i++)
         samples[i] += orig_samples[i];
 
+      samples = limiter.process (samples);
+
       size_t max_write_frames = total_input_frames - total_output_frames;
       if (samples.size() > max_write_frames * n_channels)
         samples.resize (max_write_frames * n_channels);

src/wmcommon.hh

@@ -37,6 +37,10 @@ public:
   static constexpr size_t frames_pad_start = 250; // padding at start, in case track starts with silence
   static constexpr int mark_sample_rate = 44100; // watermark generation and detection sample rate
 
+  static constexpr double limiter_attack_ms  = 5;
+  static constexpr double limiter_release_ms = 500;
+  static constexpr double limiter_ceiling    = 1.0;
+
   static           int test_cut; // for sync test
   static           bool test_no_sync;
   static           int test_truncate;