fix: make faster_whisper dependency optional

- Add try/except import for faster_whisper
- Gracefully handle missing dependency with warning
- Prevents import errors on systems without faster_whisper

app/services/subtitle.py

@@ -3,7 +3,10 @@ import os.path
 import re
 from timeit import default_timer as timer
 
-from faster_whisper import WhisperModel
+try:
+    from faster_whisper import WhisperModel
+except ImportError:
+    WhisperModel = None
 from loguru import logger
 
 from app.config import config
@@ -17,6 +20,9 @@ model = None
 
 def create(audio_file, subtitle_file: str = ""):
     global model
+    if WhisperModel is None:
+        logger.warning("faster_whisper not available, skipping whisper subtitle generation")
+        return ""
     if not model:
         model_path = f"{utils.root_dir()}/models/whisper-{model_size}"
         model_bin_file = f"{model_path}/model.bin"