TEMPO: play a sound in animated GIF/PDF/SVG

Click on the image below to see the ticking metronome (SVG version) in action:

https://agrahn.gitlab.io/svg/tempoForWeb-2.1.svg

This animate-based example comes in two versions.

The PDF version requires Acrobat Reader and is thus restricted to Windows and OSX platforms for desktop PCs. (Mobile devices are not supported.) The PDF version uses media9 for playing the embedded sound file click.mp3, taken from the animate package which already provides a ticking metronome example in its manual.

The standalone SVG version runs in most contemporary Web browsers (Firefox, Chrome, Opera ...), even on mobile devices. Here, the sound is embedded as a Base64-encoded Blob using the HTML5 <audio> tag. (click.mp3 was encoded with "base64 click.mp3" on the command line.) The physically embedded sound file makes the SVG self-contained.

In either case, playback of the sound is started by JavaScript on every frame change of the running animation. The "timeline" feature of animate is used to associate the JS code with each frame (timeline input frames.txt).

The tempo marker is implemented with a second animateinline environment. It provides 39 typical metronome speeds that can be stepped trough with the +/- buttons. The buttons make use of the animate JavaScript interface to increment and decrement the tempo marker frame number. Another timeline file, tempo.txt, associates each marker frame with a JS snippet that scales the metronome speed accordingly, again using the JS interface of animate.

PDF version, to be compiled with pdflatex, lualatex, latex+dvips+ps2pdf, or xelatex:

\documentclass[varwidth,border=12pt]{standalone}

\usepackage{tikz}
\usepackage{animate}
\usepackage{media9}
\usepackage{fontawesome5}

% tempo markers
\def\tempos{{40,42,44,46,48,50,52,54,56,58,60,63,66,69,72,76,80,84,88,92,96,100,104,108,112,116,120,126,132,138,144,152,160,168,176,184,192,200,208}}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% timeline files
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% metronome
\usepackage{filecontents}
\begin{filecontents*}{frames.txt}
::0: annotRM['click'].callAS('play');
::1: annotRM['click'].callAS('play');
::2: annotRM['click'].callAS('play');
::3: annotRM['click'].callAS('play');
\end{filecontents*}
% tempo
\newwrite\TimeLineFile
\immediate\openout\TimeLineFile=tempo.txt
\foreach \i in {0,1,...,38} {
    %JavaScript for scaling the metronome's default speed (60 frames per min)
    \pgfmathparse{\tempos[\i]/60}
    \immediate\write\TimeLineFile{::\i:anim.metronome.speed=\pgfmathresult;}
}
\immediate\closeout\TimeLineFile
%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\setlength{\textwidth}{4.4cm}

\begin{document}
\begin{center}
%the sound player  
\makebox[0pt][r]{\includemedia[
  width=1ex,height=1ex,
  label=click,
  addresource=click.mp3,
  activate=pageopen,transparent,noplaybutton,
  flashvars={source=click.mp3&hideBar=true}
]{}{APlayer.swf}}%
\makebox[4cm][l]{The \LaTeX{} Metronome}\\[1ex]

%%%%%%%%%%%
% metronome
%%%%%%%%%%%
\begin{animateinline}[label=metronome,nomouse,loop,timeline=frames.txt]{1}
  \multiframe{4}{n=1+1}{
    \begin{tikzpicture}
      \path (0.3,-0.5) rectangle (4.7,0.5);
      \shade[inner color=green,outer color=green!10] (\n,0) circle(.6);
      \foreach \i in {1,...,4} \fill[cyan] (\i,0) circle(.3);
    \end{tikzpicture}
  }
\end{animateinline}

%%%%%%%%%%%
% controls
%%%%%%%%%%%
\makebox[4cm]{%
\mediabutton[
  jsaction={
    if(anim.metronome.isPlaying) anim.metronome.stopFirst(); 
    else anim.metronome.playFwd();
  }
]{\faPowerOff}\hfill
% tempo
\mediabutton[
  jsaction={ try {--anim.tempo.frameNum;} catch (e) {} }
]{\faMinusCircle}\,%
\begin{animateinline}[label=tempo,step,nomouse,poster=10,timeline=tempo.txt]{1}
  \multiframe{39}{i=0+1}{
    \pgfmathparse{\tempos[\i]}
    \makebox[\widthof{000}][c]{\strut\pgfmathresult}
  }
\end{animateinline}\,%
\mediabutton[
  jsaction={ try {++anim.tempo.frameNum;} catch (e) {} }
]{\faPlusCircle}}
\end{center}
\end{document}

SVG version, to be compiled with

latex tempoForWeb.tex
latex tempoForWeb.tex
dvisvgm --font-format=woff --exact --zoom=-1 tempoForWeb.dvi

The SVG can be viewed standalone in a Web browser, or embedded into a Web page by means of the <object> HTML tag:

\documentclass[dvisvgm,varwidth,preview]{standalone}

\usepackage{tikz}
\usepackage{animate}
\usepackage{fontawesome5}

% tempo markers
\def\tempos{{40,42,44,46,48,50,52,54,56,58,60,63,66,69,72,76,80,84,88,92,96,100,104,108,112,116,120,126,132,138,144,152,160,168,176,184,192,200,208}}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% timeline files
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% metronome
\usepackage{filecontents}
\begin{filecontents*}{frames.txt}
::0:$('click').play();
::1:$('click').play();
::2:$('click').play();
::3:$('click').play();
\end{filecontents*}
% tempo
\newwrite\TimeLineFile
\immediate\openout\TimeLineFile=tempo.txt
\foreach \i in {0,1,...,38} {
    %JavaScript for scaling the metronome's default speed (60 frames per min)
    \pgfmathparse{\tempos[\i]/60}
    \immediate\write\TimeLineFile{::\i:anim.metronome.speed=\pgfmathresult;}
}
\immediate\closeout\TimeLineFile
%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% for producing push buttons
%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\ExplSyntaxOn
\def\controlButton#1#2{% #1:button face, #2 JavaScript
  \sbox{0}{#1}
  \makebox[0pt][l]{\usebox{0}}
  \pbs_pdfannot:nnnn{\wd0}{\ht0}{\dp0}{cursor='pointer'~onmousedown='#2'}
  \phantom{\usebox{0}}
}
\ExplSyntaxOff
%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\setlength{\textwidth}{4.4cm}

\begin{document}
% embed sound
\special{dvisvgm:rawdef
  <audio xmlns="http://www.w3.org/1999/xhtml" id='click'>
    <source
    src="data:audio/mpeg;base64,
    SUQzBAAAAAAAOlRJVDIAAAAHAAADY2xpY2sAVERSTAAAAAYAAAMyMDA4AFRTU0UAAAAPAAADTGF2
    ZjUzLjMyLjEwMAD/+5DAAAAAAAAAAAAAAAAAAAAAAABYaW5nAAAABwAAAAUAAAnKAFVVVVVVVVVV
    VVVVVVVVVVVVVVV/f39/f39/f39/f39/f39/f39/f6qqqqqqqqqqqqqqqqqqqqqqqqqq1dXV1dXV
    1dXV1dXV1dXV1dXV1dX//////////////////////////wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
    AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/+5DEAAAUjaVe1JYACx40rvMw8ABACACTCHXF
    YJgmG27XRo51BcA4AABBEMFixYsPDMzXv3mb3WLFhgYGCzl5gYOde973WOdq9evfxevXv3mZ2jCx
    Y5TtbWLHJve970669e/eb0pO3vf6L16+973v8zlKdNKXvd+9/ml74wsWLHKfOUpSk3pSjCw4MFjl
    7zM0pSl7zOUpSl73vNKUp83ve/4wvXv/lKUWL198ABkAd/AMPD/8f+uAYfHWXJSmU242sLUss7ay
    Un2Hl9HqQQKKuhNUEMwoZKsdD97mXj7TiWXCLRlUog4Z7JeI5bH4qoJcV9rXKLO5cNbKcqreQWh2
    qTo02rrDIw2anjA/Z77xC1/iM9iscSZ+yba2B/ApWjVEvjV4Wrb1M+v/2eA24Y2FypG0+mtJjT3F
    NQYWGa0WePW9tz2vWkOTFLRdNmID59aPHkY7b+KatI/niTvtyPNT4f2pS9Zd6w9eajRsyQ4snzv1
    3bdZcDksc/80LPs/5y7SLUBAACmAngSgKk6TELeQlCSZIYcJ2zKaGmKuBYEwRFP/+5LEEADWea9i
    nPSACz89K6D0sbk9RIiOCzxTlJuk4q+SRRA8hgmqRaKkR6CarTZ5WsaWYaYhKSlJuYptiU0PlWpx
    yy0iWvBppG0pkF5vKdBVtxZKTJme2lym5BEi6i6KSJFMpkGiwzbaiwj1HBZetnGj2G2WhKsqm35M
    HornJMQQmEcGbhFGhVjGRc81lV0vUmKY2EU7z2zGdf7YQ9yEzPZ3/bOlPVf1iBQDiF3JaHUb7Ur0
    ynkikWExUujIAQTEJcUNgiwKQGEL5tuRPX0gZwLNIZjjZA08is0HSplCsWegIV9MHCFgLCd0+znV
    EaknrbrCtNWdbaUmp67AhwwrTo4cVQqD2NbS64eo0cfYpPVq8408MnaLDDR7WtLDqtPZZLDCW5SB
    kTFEZmqcKyZVGDYvrqrVhcTvbeJ8qNFsxRnrBSsbLVqlEu4xcrFE3FJXSTtcl+V9Luprp3/+ly3O
    5CzVyOZglLlMp71LfT5mZmdcpo3xcXeQ2qlW6iQGXGBqhwYFD8JYQ/thu8mi7xTwWEyAVC7Fq65H
    G2mHqqRYJkeN//uSxBSA2XXrWowlLcspPKr49KW5JHyp86ohnFCjQksx3n2GIksVCcTukiOC9ISF
    qHHi2xVRdI2y20lNmJIpUGEyyRIYJhnD5Q6HHEMDY4JzSMwa65EjGlhMEDJk6Hw/Q6XOnyICV0Ya
    RSMIHaIBB3kSxKn0zbxEJyA05ow200uGGSpOYKLdEgMoTySdNkAIyR16h2O2OsLihLmjuG53XSSm
    vVfnHt63TXSxSvi3//uVu3NiDb5YcawqMqoQB6O03i2q01yavzGVxOWkuZYVGZD4GxxklpRGktJW
    G5fOPozNjZprwk+ES8WpSp2xw/A2XFDbc6xo+bNEpJFAY0/N6JARL4NIWnKMIUCqYy2LM44yeBMy
    SiDcOkPRhUUyQSIT68EsA0wTCr4fQDPXCiIVBvEgcFQhRCKaTA6drFlyWYcXC4ELiIjTVTYo+dkZ
    c0dNJLOMmdJpQxHEHk8oVojksLbqNN1xITLUiyhxKZOrGl9uCKN1soVko3kI+lyjvdL3S0sYpnVU
    QgAAACulHMW9Ii4II90acSKJ0uYppABDJtfsnv/7ksQQANcZzVfHpS3K6Dkpup6QAU7WT9ZV1Ock
    M4bCMzL2EpSYtclTTyFdlmYZmiXj3HJb1dUKs+0h5lHMVbOJlKWLj+IlStMF4Pcacs0koRBYVW0X
    KLBbW1wFQyoApGw2QnJqDE4W0dydyodTpKCygWIUBE2yWiJkJkr1aeFYlpLom3GXHFWVJXXjNEv0
    O+1Ev6WuLDeEtRqc+rLGv6k37gr8ThP+cFxLC7f2qFpdFVDMQ30WFkLUbxMEEYJosSZNwtyHM8iq
    bWlWUTS8fBCzFX+PRRVdKEqRb1tl4aRTT+SWaOGmZVGOUahrCZ7GkkTT0piGGFRL1jpBK8ZJeRom
    t0UsoZNEpqg05VxC60NHDrJC2hFRNhvELQZYWSIyESoZlXUaqDSdaSm0OhlD0U2EBPnmyyQsSQdC
    1aLEK+e8JizU0UkW9cyo13pGqRPMLMprImbps4z6einX9sYteapR+5DlvxpFbUQJeMiLhpd0U5aS
    yUAQAAA/pl68Vi/7Qg4UtK3LOso+DiUVkE2dwETAJhFmkFMTULcBf8MajmiFhyj/+5LEHQAc3e9H
    +ZmAArA33dcbQADJEyHLIgYDRFdIJGeS1Jj0UCGFQ2RLBAzdFReRYwLBQLBeOGR1ArKLZkYoF6sp
    mRoTpQMyJGhqxFjx9OtFBFknNTc1KZXplWk9MxLCzJaLGJdMEay4XhznIoXjpXJU0czOsdUTcmDI
    zJatt6SS0SZTMygmcIw2RPm5ZWRh4uvPzZDNjY6dPUdalmNaPSSnjY1Ly0C4mdRov0X/5iUHOmCa
    01IXM3PQn8RHl1AXLACAAAAMS3hWjt8TEJN45REvHKFnEP/JByCg3m/xHQ0ikRYXL/4C4gLXhhh+
    QWTCO//xUSbC4EAE4AKKDSw0b//BtINyCEgDaQZBAwawDCnARIgsJ///E2ifQsmGOFlFYOiEzAAG
    gECQ6T///w8oNyQ/wCxUBAEUQBwcAgSF9AbZCEQdMAgOLNFk/////iEorotoWJBgYMFAOBha6LMB
    ADC10ZAL0hsotgzSUhxMQU1FMy45OS4zqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
    qqqqqqqqqqqq" type="audio/mpeg"/>
%    <source src="click.mp3" type="audio/mpeg"/> % alternatively: separate mp3
  </audio>
  <script type="text/javascript">
  <![CDATA[
    function $(id) {return document.getElementById(id);};
  ]]>
  </script>
}
\begin{center}
\makebox[4cm][l]{The \LaTeX{} Metronome}\\[1ex]

%%%%%%%%%%%
% metronome
%%%%%%%%%%%
\begin{animateinline}[label=metronome,nomouse,loop,timeline=frames.txt]{1}
  \multiframe{4}{n=1+1}{
    \begin{tikzpicture}
      \path (0.3,-0.5) rectangle (4.7,0.5);
      \shade[inner color=green,outer color=green!10] (\n,0) circle(.6);
      \foreach \i in {1,...,4} \fill[cyan] (\i,0) circle(.3);
    \end{tikzpicture}
  }
\end{animateinline}

%%%%%%%%%%%
% controls
%%%%%%%%%%%
\makebox[4cm]{%
\controlButton{\faPowerOff}{%
  if(anim.metronome.isPlaying) anim.metronome.stopFirst(); 
  else anim.metronome.playFwd();
}\hfill
% tempo
\controlButton{\faMinusCircle}{%
  try {--anim.tempo.frameNum;} catch (e) {}
}\,%
\begin{animateinline}[label=tempo,step,nomouse,poster=10,timeline=tempo.txt]{1}
  \multiframe{39}{i=0+1}{
    \pgfmathparse{\tempos[\i]}
    \makebox[\widthof{000}][c]{\strut\pgfmathresult}
  }
\end{animateinline}\,%
\controlButton{\faPlusCircle}{%
  try {++anim.tempo.frameNum;} catch (e) {}
}}
\end{center}
\end{document}

Standalone, animated GIF is dumb and deaf, afaik, and there does not seem to exist an easily accessible method to synchronize an embedded Gif (in a Web page) with a sound. But SVG is much superior, since it is vectorial and thus freely scalable.