Fix truncated words list when the replacement character is decoded

tests/test_tokenizer.py

@@ -12,3 +12,13 @@ def test_tokenizer():
  assert gpt2_tokenizer.decode(gpt2_tokens) == text
  assert multilingual_tokenizer.decode(multilingual_tokens) == text
  assert len(gpt2_tokens) > len(multilingual_tokens)
+
+
+def test_split_on_unicode():
+ multilingual_tokenizer = get_tokenizer(multilingual=True)
+
+ tokens = [8404, 871, 287, 6, 246, 526, 3210, 20378]
+ words, word_tokens = multilingual_tokenizer.split_tokens_on_unicode(tokens)
+
+ assert words == [" elle", " est", " l", "'", "�", "é", "rit", "oire"]
+ assert word_tokens == [[8404], [871], [287], [6], [246], [526], [3210], [20378]]

whisper/tokenizer.py

@@ -279,17 +279,27 @@ def split_to_word_tokens(self, tokens: List[int]):
  return self.split_tokens_on_spaces(tokens)
 
  def split_tokens_on_unicode(self, tokens: List[int]):
+ decoded_full = self.decode_with_timestamps(tokens)
+ replacement_char = "\ufffd"
+
  words = []
  word_tokens = []
  current_tokens = []
+ unicode_offset = 0
 
  for token in tokens:
  current_tokens.append(token)
  decoded = self.decode_with_timestamps(current_tokens)
- if "\ufffd" not in decoded:
+
+ if (
+ replacement_char not in decoded
+ or decoded_full[unicode_offset + decoded.index(replacement_char)]
+ == replacement_char
+ ):
  words.append(decoded)
  word_tokens.append(current_tokens)
  current_tokens = []
+ unicode_offset += len(decoded)
 
  return words, word_tokens