Merge pull request #2391 from mozilla/optional-lm-test

Make language model scoring optional in Python inference code

DeepSpeech.py

@@ -870,9 +870,12 @@ def do_single_file_inference(input_file_path):
 
         logits = np.squeeze(logits)
 
+        if FLAGS.lm_binary_path:
             scorer = Scorer(FLAGS.lm_alpha, FLAGS.lm_beta,
                             FLAGS.lm_binary_path, FLAGS.lm_trie_path,
                             Config.alphabet)
+        else:
+            scorer = None
         decoded = ctc_beam_search_decoder(logits, Config.alphabet, FLAGS.beam_width, scorer=scorer)
         # Print highest probability result
         print(decoded[0][1])

evaluate.py

@@ -42,9 +42,12 @@ def sparse_tuple_to_texts(sp_tuple, alphabet):
 
 
 def evaluate(test_csvs, create_model, try_loading):
+    if FLAGS.lm_binary_path:
         scorer = Scorer(FLAGS.lm_alpha, FLAGS.lm_beta,
                         FLAGS.lm_binary_path, FLAGS.lm_trie_path,
                         Config.alphabet)
+    else:
+        scorer = None
 
     test_csvs = FLAGS.test_files.split(',')
     test_sets = [create_dataset([csv], batch_size=FLAGS.test_batch_size, train_phase=False) for csv in test_csvs]

util/flags.py

@@ -143,14 +143,6 @@ def create_flags():
 
     # Register validators for paths which require a file to be specified
 
-    f.register_validator('lm_binary_path',
-                         os.path.isfile,
-                         message='The file pointed to by --lm_binary_path must exist and be readable.')
-
-    f.register_validator('lm_trie_path',
-                         os.path.isfile,
-                         message='The file pointed to by --lm_trie_path must exist and be readable.')
-
     f.register_validator('alphabet_config_path',
                          os.path.isfile,
                          message='The file pointed to by --alphabet_config_path must exist and be readable.')