Support --short for 16 bit payload.

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

src/audiowmark.cc

@@ -57,6 +57,7 @@ print_usage()
   printf ("Global options:\n");
   printf ("  --strength <s>        set watermark strength              [%.6g]\n", Params::water_delta * 1000);
   printf ("  --linear              disable non-linear bit storage\n");
+  printf ("  --short               enable short payload mode (16 bits)\n");
   printf ("  --key <file>          load watermarking key from file\n");
   printf ("  -q, --quiet           disable information messages\n");
   printf ("\n");
@@ -183,6 +184,11 @@ parse_options (int   *argc_p,
 	{
           Params::mix = false;
 	}
+      else if (check_arg (argc, argv, &i, "--short"))
+        {
+          Params::payload_size = 16;
+          Params::payload_short = true;
+        }
       else if (check_arg (argc, argv, &i, "--hard"))
 	{
           Params::hard = true;

src/wmadd.cc

@@ -30,6 +30,7 @@
 #include "rawinputstream.hh"
 #include "rawoutputstream.hh"
 #include "stdoutwavoutputstream.hh"
+#include "shortcode.hh"
 
 using std::string;
 using std::vector;
@@ -149,7 +150,7 @@ init_frame_mod_vec (vector<vector<FrameMod>>& frame_mod_vec, int ab, const vecto
 
   /* forward error correction */
   ConvBlockType block_type  = ab ? ConvBlockType::b : ConvBlockType::a;
-  vector<int>   bitvec_fec  = randomize_bit_order (conv_encode (block_type, bitvec), /* encode */ true);
+  vector<int>   bitvec_fec  = randomize_bit_order (code_encode (block_type, bitvec), /* encode */ true);
 
   mark_sync (frame_mod_vec, ab);
   mark_data (frame_mod_vec, bitvec_fec);
@@ -553,6 +554,11 @@ add_watermark (const string& infile, const string& outfile, const string& bits)
       error ("audiowmark: cannot parse bits %s\n", bits.c_str());
       return 1;
     }
+  if (Params::payload_short && bitvec.size() != Params::payload_size)
+    {
+      error ("audiowmark: number of message bits must match payload size (%zd bits)\n", Params::payload_size);
+      return 1;
+    }
   if (bitvec.size() > Params::payload_size)
     {
       error ("audiowmark: number of bits in message '%s' larger than payload size\n", bits.c_str());

src/wmcommon.cc

@@ -18,6 +18,7 @@
 #include "wmcommon.hh"
 #include "fft.hh"
 #include "convcode.hh"
+#include "shortcode.hh"
 
 int    Params::frames_per_bit  = 2;
 double Params::water_delta     = 0.01;
@@ -25,6 +26,8 @@ bool   Params::mix             = true;
 bool   Params::hard            = false; // hard decode bits? (soft decoding is better)
 bool   Params::snr             = false; // compute/show snr while adding watermark
 int    Params::have_key        = 0;
+size_t Params::payload_size    = 128;
+bool   Params::payload_short   = false;
 int    Params::test_cut        = 0; // for sync test
 bool   Params::test_no_sync    = false; // disable sync
 bool   Params::test_no_limiter = false; // disable limiter
@@ -209,7 +212,7 @@ data_frame_pos (int f)
 size_t
 mark_data_frame_count()
 {
-  return conv_code_size (ConvBlockType::a, Params::payload_size) * Params::frames_per_bit;
+  return code_size (ConvBlockType::a, Params::payload_size) * Params::frames_per_bit;
 }
 
 size_t

src/wmcommon.hh

@@ -43,7 +43,8 @@ public:
   static           bool snr;                       // compute/show snr while adding watermark
   static           int  have_key;
 
-  static constexpr size_t payload_size     = 128;  // number of payload bits for the watermark
+  static           size_t payload_size;            // number of payload bits for the watermark
+  static           bool   payload_short;
 
   static constexpr int sync_bits           = 6;
   static constexpr int sync_frames_per_bit = 85;

src/wmget.cc

@@ -24,6 +24,7 @@
 #include "wavdata.hh"
 #include "wmcommon.hh"
 #include "convcode.hh"
+#include "shortcode.hh"
 
 using std::string;
 using std::vector;
@@ -758,7 +759,7 @@ public:
     SyncFinder sync_finder;
     sync_scores = sync_finder.search (wav_data, SyncFinder::Mode::BLOCK);
 
-    vector<float> raw_bit_vec_all (conv_code_size (ConvBlockType::ab, Params::payload_size));
+    vector<float> raw_bit_vec_all (code_size (ConvBlockType::ab, Params::payload_size));
     vector<int>   raw_bit_vec_norm (2);
 
     SyncFinder::Score score_all { 0, 0 };
@@ -787,13 +788,13 @@ public:
               {
                 raw_bit_vec = linear_decode (fft_range_out, wav_data.n_channels());
               }
-            assert (raw_bit_vec.size() == conv_code_size (ConvBlockType::a, Params::payload_size));
+            assert (raw_bit_vec.size() == code_size (ConvBlockType::a, Params::payload_size));
 
             raw_bit_vec = randomize_bit_order (raw_bit_vec, /* encode */ false);
 
             /* ---- deal with this pattern ---- */
             float decode_error = 0;
-            vector<int> bit_vec = conv_decode_soft (sync_score.block_type, normalize_soft_bits (raw_bit_vec), &decode_error);
+            vector<int> bit_vec = code_decode_soft (sync_score.block_type, normalize_soft_bits (raw_bit_vec), &decode_error);
 
             result_set.add_pattern (sync_score, bit_vec, decode_error, ResultSet::Type::BLOCK);
             total_count += 1;
@@ -819,7 +820,7 @@ public:
                     ab_bits[i * 2] = ab_raw_bit_vec[0][i];
                     ab_bits[i * 2 + 1] = ab_raw_bit_vec[1][i];
                   }
-                vector<int> bit_vec = conv_decode_soft (ConvBlockType::ab, normalize_soft_bits (ab_bits), &decode_error);
+                vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, normalize_soft_bits (ab_bits), &decode_error);
                 score_ab.index = sync_score.index;
                 score_ab.quality = (ab_quality[0] + ab_quality[1]) / 2;
                 result_set.add_pattern (score_ab, bit_vec, decode_error, ResultSet::Type::BLOCK);
@@ -839,7 +840,7 @@ public:
         vector<float> soft_bit_vec = normalize_soft_bits (raw_bit_vec_all);
 
         float decode_error = 0;
-        vector<int> bit_vec = conv_decode_soft (ConvBlockType::ab, soft_bit_vec, &decode_error);
+        vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, soft_bit_vec, &decode_error);
 
         result_set.add_pattern (score_all, bit_vec, decode_error, ResultSet::Type::ALL);
       }
@@ -943,7 +944,7 @@ class ClipDecoder
               }
 
             float decode_error = 0;
-            vector<int> bit_vec = conv_decode_soft (ConvBlockType::ab, normalize_soft_bits (raw_bit_vec), &decode_error);
+            vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, normalize_soft_bits (raw_bit_vec), &decode_error);
 
             SyncFinder::Score sync_score_nopad = sync_score;
             sync_score_nopad.index = time_offset_sec * wav_data.sample_rate();