melodyflow loudness fix

app.py

@@ -188,12 +188,21 @@ def transform_with_melodyflow_api(audio_path, variation, custom_prompt="", solve
         # Result is a tuple of 3 audio files (variations)
         # We'll use the first variation
         if result and len(result) > 0 and result[0]:
-            # Save the result locally
+            # Save the result locally with loudness normalization
             output_filename = f"melodyflow_{variation}_{random.randint(1000, 9999)}.wav"
             
-            # Copy the result file to our local filename
-            import shutil
-            shutil.copy2(result[0], output_filename)
+            # Load the result and apply consistent loudness normalization
+            transformed_audio, sr = torchaudio.load(result[0])
+            
+            # Re-save with same loudness strategy as your MusicGen (no headroom)
+            audio_write(
+                output_filename.replace('.wav', ''), 
+                transformed_audio, 
+                sr, 
+                strategy="loudness", 
+                loudness_compressor=True
+                # Note: no loudness_headroom_db parameter like Facebook uses
+            )
             
             return output_filename, status_msg
         else: