diff options
| -rw-r--r-- | doc/documentation.tex | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/doc/documentation.tex b/doc/documentation.tex index fe58ba6..a6ba82b 100644 --- a/doc/documentation.tex +++ b/doc/documentation.tex @@ -72,11 +72,15 @@ seconds a new discovery packet is emitted by soundbox. Thus it can take up to \section{Playing audio} \label{playing-audio} Audio can be streamed to \texttt{soundbox} devices with the \texttt{ffmpeg} -command. Audio files or internet stream addresses can be passed as input. +command. Audio files or internet stream addresses can be passed as input. Since +\texttt{ffmpeg} supports multiple outputs, multiple \texttt{soundbox} devices +can be targeted with their IP addresses. \begin{verbatim} -ffmpeg -re -i <input> -acodec libmp3lame -f matroska \ - udp://224.0.0.99:5316 +ffmpeg -re -i <input> \ + -acodec flac -f ogg tcp://<ip-1>:5316 \ + -acodec flac -f ogg tcp://<ip-2>:5316 \ + ... \end{verbatim} More details about FFmpeg streaming can be read from the FFmpeg streaming @@ -261,26 +265,60 @@ option has to be inserted instead: echo 'dtparam=audio=on' >> /media/mmcblk0p1/config.txt \end{verbatim} +\subsection{soundbox script} + +soundbox uses the command \texttt{ffplay} for playback. A script has to be +added to call the command over and over again to allow new connections. The +script can be added with \texttt{echo} and is made executable with +\texttt{chmod}. \texttt{lbu add} will make sure that the script will be made +persistent by calling \texttt{lbu commit} later (see +section~\ref{lbu-persistence}). + +\begin{verbatim} +echo '#!/bin/ash + +set -e + +while true +do + ffplay -autoexit tcp://0.0.0.0:5316?listen +done' > /usr/local/bin/soundbox + +chmod 755 /usr/local/bin/soundbox + +lbu add /usr/local/bin/soundbox +\end{verbatim} + +This makes the command \texttt{soundbox} available on the system. + \subsection{Service configuration} To receive audio streams via the network it is required to run the -\texttt{ffplay} command continuously. This is possible by creating a service -file for the OpenRC init system with \texttt{echo} and enabling the service -with \texttt{rc-update}. +\texttt{soundbox} command continuously. This is possible by creating a service +file for the OpenRC init system with \texttt{echo}, making that executable with +\texttt{chmod} and enabling the service with \texttt{rc-update}. Also here +\texttt{lbu add} makes sure that the service file will be made persistent later +(see section~\ref{lbu-persistence} for details). \begin{verbatim} echo '#!/sbin/openrc-run name="soundbox" -command="/usr/bin/ffplay" -command_args="udp://224.0.0.99:5316" +command="/usr/local/bin/soundbox" +command_args="" pidfile="/run/soundbox.pid" command_background=true' > /etc/init.d/soundbox +chmod 755 /etc/init.d/soundbox + rc-update add soundbox default + +lbu add /etc/init.d/soundbox \end{verbatim} -\subsection{Persistence of changes and reboot} +This will make sure the soundbox script is run on every boot. + +\subsection{Persistence of changes and reboot}\label{lbu-persistence} Since a diskless Alpine Linux installation is preferred for soundbox the changes have to be made persistent with \texttt{lbu}. Rebooting after it makes |