small fixes

app.py

@@ -145,7 +145,7 @@ def process(
     end = time.time()
 
     metadata = torchaudio.info(filename)
-    duration = wave.num_frames / sample_rate
+    duration = metadata.num_frames / sample_rate
     rtf = (end - start) / duration
 
     logging.info(f"Finished at {date_time} s. Elapsed: {end - start: .3f} s")

model.py

@@ -163,6 +163,10 @@ def _get_gigaspeech_pre_trained_model(
         num_active_paths=num_active_paths,
     )
 
+    recognizer = sherpa.OfflineRecognizer(config)
+
+    return recognizer
+
 
 @lru_cache(maxsize=10)
 def _get_librispeech_pre_trained_model(