# media9 mp4 video not playing

In theory, media9 should be able to embed MP4 movies into a PDF. The document is compiled fine with PDFlatex, but I get a blank screen when opening it in Adobe PDF on Windows 10.

Below is a minimal TEX example. I created the MP4 movie with Kazam in Ubuntu 18 as a screencast of a couple of seconds, that outputs with codec H264 MPEG-4 AVC part 10 (avc1).

\documentclass{article}
\usepackage{media9}

\begin{document}
\begin{figure}
\includemedia[
width=\textwidth,
height=0.56\textwidth,
flashvars={
source=test.mp4
&autoPlay=true
}
]{}{VPlayer.swf}

\includemedia[
width=\textwidth,
height=0.56\textwidth,
flashvars={
source=test.flv
&autoPlay=true
}
]{}{VPlayer.swf}
\end{figure}
\end{document}


If I convert the MP4 to FLV using ffmpeg, then it works, but it takes 5 times more space on disk, and in addition much worse resolution. I am curious if there is a way to fix the MP4 inclusion, as the H264 codec is said to be supported by media9 and Flash Player.

ffmpeg -i test.mp4 test.flv


Any help is welcome. Thanks.

ffmpeg -i test.mp4 -profile:v high -pix_fmt yuv420p -g 300 test_postprocess.mp4