diff --git a/Makefile b/Makefile
index 3789a89..f877125 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,7 @@ all : sample0.xex sample1.xex sample2.xex sample3.xex sample4.xex sample5.xex sa
 %.s : %.jpg dither-image.js
 	node dither-image.js $< $@
 	./gif.sh $@
+	./mp4.sh $@
 
 chickens.s : chickens.wav pack-wav.js
 	node pack-wav.js $< $@
diff --git a/gif.sh b/gif.sh
index 6cf2305..3fbffd6 100755
--- a/gif.sh
+++ b/gif.sh
@@ -1,4 +1,4 @@
-fps=60000/1001
+fps=30000/1001
 
 ffmpeg \
     -r $fps -i "$1.%01d.png" \
diff --git a/mp4.sh b/mp4.sh
new file mode 100755
index 0000000..db3e494
--- /dev/null
+++ b/mp4.sh
@@ -0,0 +1,7 @@
+fps=30000/1001
+
+ffmpeg \
+    -r $fps -i "$1.%01d.png" \
+    -vf scale=w=640:h=384:sws_flags=neighbor,format=yuv420p \
+    -g 480 \
+    -y "$1.mp4"