glasscoder-ipc

7 October 2019 Linux Audio Manual

glasscoder-ipc

IPC methods for the GlassCoder stream encoder

          glasscoder
          OPTIONS

## Description

`glasscoder` 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 `glasscoder` 1 man page.

A running `glasscoder` 1 instance can be monitored and controlled by means of two different IPC methods: its standard input/output streams and HTTP calls.

## Monitoring via Standard Output

`glasscoder` 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 `--errors-to` and `--meter-data` options.

When `--errors-to=STDOUT` is specified, `glasscoder` 1 will output error messages on standard output in the following machine-readable format:

          ER priority msg

where `priority` is an integer the indicates the priority level of the error as defined by the `syslog` 3 interface and `msg` is a text string describing the error. Each message is terminated by a newline character.

When `--meter-data` is specified, `glasscoder` 1 will output realtime audio level information suitable for being rendered as an audio meter display in the following format:

          ME left-lvlright-lvl

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.

## Control via Standard Input

`glasscoder` 1 supports the following command, sent via standard input:

          MD text

Send the metadata `text` to the stream. The command should be terminated by newline.

## Control via HTTP

If the `--metadata-port=`port`` 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 `glasscoder` 1 man page.

## Proxy Connections

It is possible to implement proxy connectors for `glasscoder` 1's IceStreamer server through use of the `--server-pipe` 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 `SCM_RIGHTS` message type. See the `unix` 7 man page for more information. A fully worked-out example is also available in the GlassCoder source package in the 'src/tests/' subdirectory.

## Author

Fred Gleason <fredg@paravelsystems.com>

## See Also

glasscoder

1 ,

cmsg

3 ,

sendmsg

2 ,

syslog

3 ,

unix

7