ctcdecode binding fixes

native_client/ctcdecode/Makefile

@@ -4,6 +4,11 @@ include ../definitions.mk
 
 NUM_PROCESSES ?= 1
 
+# ARM64 can't find the proper libm.so without this
+ifeq ($(TARGET),rpi3-armv8)
+LDFLAGS_NEEDED += $(RASPBIAN)/lib/aarch64-linux-gnu/libm-2.24.so
+endif
+
 all: bindings
 
 clean:
@@ -12,7 +17,7 @@ clean:
 
 bindings: clean
 	pip install --quiet $(PYTHON_PACKAGES) wheel==0.31.0 setuptools==39.1.0
-	AS=$(AS) CC=$(CC) CXX=$(CXX) LD=$(LD) CFLAGS="$(CFLAGS) $(CXXFLAGS)" LDFLAGS="$(LDFLAGS_NEEDED)" $(PYTHON_PATH) $(NUMPY_INCLUDE) python ./setup.py build --num_processes $(NUM_PROCESSES) $(PYTHON_PLATFORM_NAME) $(SETUP_FLAGS)
+	AS=$(AS) CC=$(CC) CXX=$(CXX) LD=$(LD) CFLAGS="$(CFLAGS) $(CXXFLAGS)" LDFLAGS="$(LDFLAGS_NEEDED)" $(PYTHON_PATH) $(NUMPY_INCLUDE) python ./setup.py build_ext --num_processes $(NUM_PROCESSES) $(PYTHON_PLATFORM_NAME) $(SETUP_FLAGS)
 	find temp_build -type f -name "*.o" -delete
 	AS=$(AS) CC=$(CC) CXX=$(CXX) LD=$(LD) CFLAGS="$(CFLAGS) $(CXXFLAGS)" LDFLAGS="$(LDFLAGS_NEEDED)" $(PYTHON_PATH) $(NUMPY_INCLUDE) python ./setup.py bdist_wheel --num_processes $(NUM_PROCESSES) $(PYTHON_PLATFORM_NAME) $(SETUP_FLAGS)
 	rm -rf temp_build

native_client/ctcdecode/__init__.py

@@ -27,7 +27,7 @@ def ctc_beam_search_decoder(probs_seq,
                             beam_size,
                             cutoff_prob=1.0,
                             cutoff_top_n=40,
-                            ext_scoring_func=None):
+                            scorer=None):
     """Wrapper for the CTC Beam Search Decoder.
 
     :param probs_seq: 2-D list of probability distributions over each time
@@ -45,17 +45,16 @@ def ctc_beam_search_decoder(probs_seq,
                          characters with highest probs in alphabet will be
                          used in beam search, default 40.
     :type cutoff_top_n: int
-    :param ext_scoring_func: External scoring function for
-                             partially decoded sentence, e.g. word count
-                             or language model.
-    :type external_scoring_func: callable
+    :param scorer: External scorer for partially decoded sentence, e.g. word
+                   count or language model.
+    :type scorer: Scorer
     :return: List of tuples of log probability and sentence as decoding
              results, in descending order of the probability.
     :rtype: list
     """
     beam_results = swigwrapper.ctc_beam_search_decoder(
         probs_seq, alphabet.config_file(), beam_size, cutoff_prob, cutoff_top_n,
-        ext_scoring_func)
+        scorer)
     beam_results = [(res.probability, alphabet.decode(res.tokens)) for res in beam_results]
     return beam_results
 
@@ -67,7 +66,7 @@ def ctc_beam_search_decoder_batch(probs_seq,
                                   num_processes,
                                   cutoff_prob=1.0,
                                   cutoff_top_n=40,
-                                  ext_scoring_func=None):
+                                  scorer=None):
     """Wrapper for the batched CTC beam search decoder.
 
     :param probs_seq: 3-D list with each element as an instance of 2-D list
@@ -88,17 +87,16 @@ def ctc_beam_search_decoder_batch(probs_seq,
     :type cutoff_top_n: int
     :param num_processes: Number of parallel processes.
     :type num_processes: int
-    :param ext_scoring_func: External scoring function for
-                             partially decoded sentence, e.g. word count
-                             or language model.
-    :type external_scoring_function: callable
+    :param scorer: External scorer for partially decoded sentence, e.g. word
+                   count or language model.
+    :type scorer: Scorer
     :return: List of tuples of log probability and sentence as decoding
              results, in descending order of the probability.
     :rtype: list
     """
     batch_beam_results = swigwrapper.ctc_beam_search_decoder_batch(
         probs_seq, seq_lengths, alphabet.config_file(), beam_size, num_processes,
-        cutoff_prob, cutoff_top_n, ext_scoring_func)
+        cutoff_prob, cutoff_top_n, scorer)
     batch_beam_results = [
         [(res.probability, alphabet.decode(res.tokens)) for res in beam_results]
         for beam_results in batch_beam_results

native_client/ctcdecode/scorer.cpp

@@ -43,6 +43,16 @@ Scorer::Scorer(double alpha,
   setup(lm_path, trie_path);
 }
 
+Scorer::Scorer(double alpha,
+               double beta,
+               const std::string& lm_path,
+               const std::string& trie_path,
+               const char* alphabet_config_path)
+  : Scorer(alpha, beta, lm_path, trie_path, Alphabet(alphabet_config_path))
+{
+
+}
+
 Scorer::~Scorer() {
 }
 
@@ -114,7 +124,7 @@ void Scorer::save_dictionary(const std::string& path) {
 }
 
 double Scorer::get_log_cond_prob(const std::vector<std::string>& words) {
-  double cond_prob;
+  double cond_prob = OOV_SCORE;
   lm::ngram::State state, tmp_state, out_state;
   // avoid to inserting <s> in begin
   language_model_->NullContextWrite(&state);

native_client/ctcdecode/scorer.h

@@ -46,6 +46,11 @@ class Scorer {
          const std::string &lm_path,
          const std::string &trie_path,
          const Alphabet &alphabet);
+  Scorer(double alpha,
+         double beta,
+         const std::string &lm_path,
+         const std::string &trie_path,
+         const char* alphabet_config_path);
   ~Scorer();
 
   double get_log_cond_prob(const std::vector<std::string> &words);

native_client/ctcdecode/setup.py

@@ -84,14 +84,9 @@ def _single_compile(obj):
         'unittest.cc'))
 ]
 
-LIBS = ['stdc++']
-if platform.system() != 'Darwin':
-    LIBS.append('rt')
-
 ARGS = ['-O3', '-DNDEBUG', '-DKENLM_MAX_ORDER=6', '-std=c++11',
         '-Wno-unused-local-typedef', '-Wno-sign-compare']
 
-
 decoder_module = Extension(
     name='ds_ctcdecoder._swigwrapper',
     sources=['swigwrapper.i'] + FILES + glob.glob('*.cpp'),
@@ -104,7 +99,6 @@ def _single_compile(obj):
         'third_party/openfst-1.6.7/src/include',
         'third_party/ThreadPool',
     ],
-    libraries=LIBS,
     extra_compile_args=ARGS
 )
 

native_client/ctcdecode/swigwrapper.i

@@ -6,6 +6,7 @@
 %}
 
 %include "pyabc.i"
+%include "std_string.i"
 %include "std_vector.i"
 %include "numpy.i"
 
@@ -61,6 +62,9 @@ mod_decoder_batch(const double *probs,
 }
 %}
 
+
+%ignore Scorer::dictionary;
+
 %include "output.h"
 %include "scorer.h"
 %include "ctc_beam_search_decoder.h"