diff --git a/README.md b/README.md
index 45a29df..6bffdfa 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
-# Longan_GD32VF_examples
-example project for Longan Nano (GD32VF)
+# Sipeed Longan Nano movie player
+
+Convert your 160x80 frames to RGB565 using `png2rgb565.py`, concat them
+into movie.bin and copy the file to the SD card.
diff --git a/movies/png2rgb565.py b/movies/png2rgb565.py
new file mode 100755
index 0000000..9113f04
--- /dev/null
+++ b/movies/png2rgb565.py
@@ -0,0 +1,31 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Based on https://gist.github.com/hidsh/7065820
+
+from PIL import Image
+import struct, os, sys
+
+def write_bin(f, pixel_list):
+    for pix in pixel_list:
+        # RGB565: RRRR RGGG  GGGB BBBB
+        r = (pix[0] >> 3) & 0x1F
+        g = (pix[1] >> 2) & 0x3F
+        b = (pix[2] >> 3) & 0x1F
+        # big endian u16
+        f.write(struct.pack('>H', (r << 11) + (g << 5) + b))
+
+args = sys.argv
+if len(args) != 2:
+    print('./png2rgb565.py HOGE.png')
+    exit(1)
+
+in_path = args[1]
+
+body, _ = os.path.splitext(in_path)
+out_path = body + '.rgb'
+
+img = Image.open(in_path).convert('RGB')
+
+with open(out_path, 'wb') as f:
+    write_bin(f, img.getdata())