Handle the case when there is no voice in the video and text to translate

Author: jordimas

open_dubbing/translation.py

@@ -130,7 +130,11 @@ def _add_translations(
         stripped_translation = re.sub(
             rf"^\s*{_BREAK_MARKER}\s*|\s*{_BREAK_MARKER}\s*$", "", translated_script
         )
-        text_segments = stripped_translation.split(_BREAK_MARKER)
+        if stripped_translation:
+            text_segments = stripped_translation.split(_BREAK_MARKER)
+        else:
+            text_segments = []
+
         if len(utterance_metadata) != len(text_segments):
             raise ValueError(
                 "The utterance metadata must be of the same length as the text"

tests/translation_test.py

@@ -139,6 +139,11 @@ def test_generate_script(self, test_name, utterance_metadata, expected_script):
                     },
                 ],
             ),
+            (
+                [],
+                "",
+                [],
+            ),
         ],
     )
     def test_add_translations(