如何同时播放2个视频？

Question

我想在同一页面上同步播放 4 个视频。这可以通过同时启动所有视频来实现。怎么做？这是包含 2 个视频的 MWE。

\documentclass{article}
\usepackage{media9}

\begin{document}

\begin{figure*}
\fbox
{\includemedia[
    activate=pageopen,
    width=0.475\textwidth,
    addresource={VertOscAmp(a0_05h0_25dZ1w1_g1rmax20mu0_001)a.mp4},
    flashvars={%
        src=VertOscAmp(a0_05h0_25dZ1w1_g1rmax20mu0_001)a.mp4
        &scaleMode=stretch}
]{}}{StrobeMediaPlayback.swf}}
    \hfill
\fbox
{\includemedia[
    activate=pageopen,
    width=0.475\textwidth,
    addresource={VertOscAmp(a0_25h1dZ1w1_g1rmax20mu0_001)b.mp4},
    flashvars={%
        src=VertOscAmp(a0_25h1dZ1w1_g1rmax20mu0_001)b.mp4
        &scaleMode=stretch}
]{}}{StrobeMediaPlayback.swf}}
\\
\caption{caption}
\label{fig:VertOscAmp}
\end{figure*}

\end{document}