Use longer frames (23ms -> 46ms).

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

src/wmcommon.cc

@@ -19,7 +19,7 @@
 #include "fft.hh"
 #include "convcode.hh"
 
-int    Params::frames_per_bit  = 2;
+int    Params::frames_per_bit  = 1;
 double Params::water_delta     = 0.01;
 bool   Params::mix             = true;
 bool   Params::hard            = false; // hard decode bits? (soft decoding is better)

src/wmcommon.hh

@@ -31,11 +31,11 @@ enum class Format { AUTO = 1, RAW = 2 };
 class Params
 {
 public:
-  static constexpr size_t frame_size      = 1024;
+  static constexpr size_t frame_size      = 2048;
   static           int    frames_per_bit;
   static constexpr size_t bands_per_frame = 30;
-  static constexpr int max_band          = 100;
-  static constexpr int min_band          = 20;
+  static constexpr int max_band          = 200;
+  static constexpr int min_band          = 40;
 
   static           double water_delta;
   static           bool mix;
@@ -46,12 +46,12 @@ public:
   static constexpr size_t payload_size     = 128;  // number of payload bits for the watermark
 
   static constexpr int sync_bits           = 6;
-  static constexpr int sync_frames_per_bit = 85;
+  static constexpr int sync_frames_per_bit = 42;
   static constexpr int sync_search_step    = 256;
   static constexpr int sync_search_fine    = 8;
   static constexpr double sync_threshold2  = 0.7; // minimum refined quality
 
-  static constexpr size_t frames_pad_start = 250; // padding at start, in case track starts with silence
+  static constexpr size_t frames_pad_start = 125; // 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_block_size_ms = 1000;