Consistent verify logic

loki/remux.py

@@ -193,8 +193,15 @@ def mux(media):
     logger.debug(f"Mux result: {merge}")
 
     # Verify
-    if merge.returncode != 0 or not temp.exists() or temp.stat().st_size < (min_size * size):
-      logger.error(f"Mux error: {merge.stdout.decode('utf-8')}")
+    err = None
+    if merge.returncode != 0:
+      err = f"Non-zero exit code: {merge.returncode}"
+    elif not temp.exists():
+      err = 'file missing'
+    elif temp.stat().st_size < (min_size * size):
+      err = 'file too small'
+    if err is not None:
+      logger.error(f"Mux error ({err}):\n{merge.stdout.decode('utf-8')}")
       continue
 
     # Set xattr
@@ -226,9 +233,9 @@ def mux(media):
     except BaseException as e:
       err = e
     if not final.exists():
-      err = 'Output file missing'
+      err = 'file missing'
     elif final.stat().st_size < (min_size * size):
-      err = 'Output file too small'
+      err = 'file too small'
     if err is not None:
       logger.error(f"Rename error ({final}): {err}")
       continue