diff --git a/waves/doppler/README.md b/waves/doppler/README.md
index af8c038..8f05bf3 100644
--- a/waves/doppler/README.md
+++ b/waves/doppler/README.md
@@ -1 +1 @@
-ffmpeg -framerate 15 -f image2 -pattern_type glob -i "*.png" -vcodec mpeg4 -c:v libx264 -crf 20 doppler.mp4
+ffmpeg -framerate 15 -f image2 -pattern_type glob -i "*.png" -vcodec mpeg4 -c:v libx264 -crf 20 -pix_fmt yuv420p -movflags +faststart doppler.mp4
diff --git a/waves/doppler/doppler.mp4 b/waves/doppler/doppler.mp4
index 8e19763..62ba436 100644
Binary files a/waves/doppler/doppler.mp4 and b/waves/doppler/doppler.mp4 differ
diff --git a/waves/doppler2/README.md b/waves/doppler2/README.md
index 74e030a..07fa705 100644
--- a/waves/doppler2/README.md
+++ b/waves/doppler2/README.md
@@ -1 +1 @@
-ffmpeg -framerate 15 -f image2 -pattern_type glob -i "*.png" -vcodec mpeg4 -c:v libx264 -crf 20 doppler2.mp4
+ffmpeg -framerate 15 -f image2 -pattern_type glob -i "*.png" -vcodec mpeg4 -c:v libx264 -crf 20 -pix_fmt yuv420p -movflags +faststart doppler2.mp4