How to play background music across multiple slides when making a beamer presentation?

Question

I made a LaTeX beamer presentation and I would like to add background music to some of the slides. I did manage to play something using the media9 package, but only on a single slide, i.e. the sound stops when going to the next slide. Is it possible to embed a soundfile, let's say an MP3, that starts playing at a specific slide x and stops at another slide y (using media9 or any other package)?

Answer 1

There is a deactivate option with media9 inclusion command \includemedia. Default setting of deactivate is pageclose to unload the media player upon page change. If set to onclick, the media keeps playing in the background.

To automatically start playing, the activate command option must be set to either pageopen or pagevisible and the autoPlay Flash variable of the player must be set to true. In the code below, the sound starts playing automatically when a particular slide is opened. The sound keeps playing after leaving the slide.

To auto-stop the sound on a particular slide, we need some JavaScript that is run upon /O (page open) event of that slide.

Since version 11 of Adobe Reader, the media inclusion must take up some space (width x height) on the PDF page, otherwise the media remains dumb. In order to make the sound annotation invisible we make it transparent and suppress the progress bar of the sound player and place the whole thing after the slide heading.

\documentclass{beamer}
\usepackage{media9}

\begin{document}

\begin{frame}{dumb frame}
\dots
\end{frame}

\begin{frame}{frame with sound \includemedia[
  label=my_sound,
  width=1ex, height=1ex, transparent,
  activate=pageopen, deactivate=onclick,
  addresource=sound_sample.mp3,
  flashvars={
    source=sound_sample.mp3
   &autoPlay=true
   &hideBar=true
  },
]{}{APlayer.swf}}
\dots
\end{frame}

\begin{frame}{other frame}
\dots
\end{frame}

\pdfpageattr{/AA <</O <</S/JavaScript/JS (annotRM['my_sound'].activated=false;)>> >>}
\begin{frame}{frame where sound stops}
\dots
\end{frame}

\begin{frame}{another dumb frame}
\dots
\end{frame}

\end{document}