'\" t
.\"     Title: glasscoder-ipc
.\"    Author: Fred Gleason <fredg@paravelsystems.com>
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 03/12/2021
.\"    Manual: Linux Audio Manual
.\"    Source: October 2019
.\"  Language: English
.\"
.TH "GLASSCODER\-IPC" "7" "03/12/2021" "October 2019" "Linux Audio Manual"
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  .SH "NAME"
glasscoder-ipc \- IPC methods for the GlassCoder stream encoder

  

  
  .SH "SYNOPSIS"

    .HP \w'\fBglasscoder\fR\ 'u

      \fBglasscoder\fR
       [\fIOPTIONS\fR]
      
.br

    

  

  .SH "DESCRIPTION"

  .PP
\fBglasscoder\fR(1)
is an audio encoder that is capable of generating live streams using a variety of formats and sending them to an Icecast or Shoutcast audio streaming server or posting them as HTTP Live Streams [HLS]\&. For more information regarding its overall capabilities, see the
\fBglasscoder\fR(1)
man page\&.

  .PP
A running
\fBglasscoder\fR(1)
instance can be monitored and controlled by means of two different IPC methods: its standard input/output streams and HTTP calls\&.

  

  .SH "MONITORING VIA STANDARD OUTPUT"

  .PP
\fBglasscoder\fR(1)
can output realtime information about current operating state via its standard output and/or error streams\&. The location and format in which this information is generated is controlled by means of the
\fB\-\-errors\-to\fR
and
\fB\-\-meter\-data\fR
options\&.

  .PP
When
\fB\-\-errors\-to=STDOUT\fR
is specified,
\fBglasscoder\fR(1)
will output error messages on standard output in the following machine\-readable format:

  .PP
.if n \{\
.RS 4
.\}
.nf
      ER  [\fIpriority\fR]  [\fImsg\fR]
    
.fi
.if n \{\
.RE
.\}
.sp


  .PP
where
[\fIpriority\fR]
is an integer the indicates the priority level of the error as defined by the
\fBsyslog\fR(3)
interface and
[\fImsg\fR]
is a text string describing the error\&. Each message is terminated by a newline character\&.

  .PP
When
\fB\-\-meter\-data\fR
is specified,
\fBglasscoder\fR(1)
will output realtime audio level information suitable for being rendered as an audio meter display in the following format:

  .PP
.if n \{\
.RS 4
.\}
.nf
      ME  [\fIleft\-lvl\fR\fIright\-lvl\fR]
    
.fi
.if n \{\
.RE
.\}
.sp


  .PP
where each argument is the current audio level of the corresponding channel in hexidecimal, referenced to 0 dBFS\&. Each message is terminated by a newline character\&.

  

  .SH "CONTROL VIA STANDARD INPUT"

  .PP
\fBglasscoder\fR(1)
supports the following command, sent via standard input:

  .PP
.if n \{\
.RS 4
.\}
.nf
      MD  [\fItext\fR]
    
.fi
.if n \{\
.RE
.\}
.sp


  .PP
Send the metadata
[\fItext\fR]
to the stream\&. The command should be terminated by newline\&.

  

  .SH "CONTROL VIA HTTP"

  .PP
If the
\fB\-\-metadata\-port=\fR\fB\fIport\fR\fR
option is given a non\-zero value, metadata updates can be sent to the stream by means of HTTP calls\&. For details, see the METADATA section of the
\fBglasscoder\fR(1)
man page\&.

  

  .SH "PROXY CONNECTIONS"

  .PP
It is possible to implement proxy connectors for
\fBglasscoder\fR(1)\*(Aqs IceStreamer server through use of the
\fB\-\-server\-pipe\fR
command switch\&. This switch will create a UNIX socket which can be used to pipe in open descriptors for player connections by means of ancilliary socket messages with the
\fBSCM_RIGHTS\fR
message type\&. See the
\fBunix\fR(7)
man page for more information\&. A fully worked\-out example is also available in the GlassCoder source package in the \*(Aqsrc/tests/\*(Aq subdirectory\&.

  

  .SH "AUTHOR"

  .PP
Fred Gleason <fredg@paravelsystems\&.com>

  

  .SH "SEE ALSO"

  .PP
\fBglasscoder\fR(1),
\fBcmsg\fR(3),
\fBsendmsg\fR(2),
\fBsyslog\fR(3),
\fBunix\fR(7)

  
.SH "AUTHOR"
.PP
\fBFred Gleason\fR <\&fredg@paravelsystems\&.com\&>
.RS 4
Application Author
.RE