diff --git a/decoder.py b/decoder.py
index b23d623..b5d198e 100644
--- a/decoder.py
+++ b/decoder.py
@@ -15,7 +15,7 @@ parser.add_argument("-s", "--size", help="number of bytes to decode", type=int)
 parser.add_argument("-p", "--psize", help="packet size", type=int)
 args = parser.parse_args()
 
-cheight = cwidth = max(args.height // 10, args.width // 10)
+cheight = cwidth = max(args.height // 15, args.width // 15)
 frame_size = args.height * args.width - 4 * cheight * cwidth
 frame_bytes = frame_size * 3 // 8
 frame_xor = np.arange(frame_bytes, dtype=np.uint8)
diff --git a/encoder.py b/encoder.py
index d71990d..ab0ab1e 100644
--- a/encoder.py
+++ b/encoder.py
@@ -15,7 +15,7 @@ parser.add_argument("-m", "--mix", help="mix frames with original video", action
 args = parser.parse_args()
 
 
-cheight = cwidth = max(args.height // 10, args.width // 10)
+cheight = cwidth = max(args.height // 15, args.width // 15)
 midwidth = args.width - 2 * cwidth
 frame_size = args.height * args.width - 4 * cheight * cwidth
 # Divide by 8 / 3 for 3-bit color