Provided by: ezstream_0.5.6~dfsg-1.1_amd64 
NAME
ezstream — source client for Icecast with external de-/encoder support
SYNOPSIS
ezstream [-hnqVv] -c configfile
ezstream -s [playlist]
DESCRIPTION
The ezstream utility is a source client for the Icecast media streaming server. In its
basic mode of operation, it streams media files and data from standard input "as-is" — such
as Ogg Vorbis, Ogg Theora and MP3 — to a server. It can also use various external decoders
and encoders to re-encode from one format to another, and stream the result. The only
requirement is that the external programs support writing to or reading from standard input,
and can be used from the command line.
Command line parameters
-c configfile
Use the XML configuration in configfile.
-h Print a summary of available command line parameters with short descriptions and
exit.
-n Normalize metadata strings by removing excess whitespaces.
-q Be more quiet. Suppress the output that external programs send to standard error.
-s [playlist]
Run ezstream as a line-based shuffling utility. If no playlist argument is given, a
list of media file names is read from standard input instead of an input file.
After successfully reading the entire list, it is shuffled and printed to standard
output, and ezstream will exit.
-V Print the ezstream version number and exit.
-v Produce more verbose output from ezstream. Use twice for even more verbose output.
When the -q and -v parameters are provided simultaneously, an additional line of information
about the currently streamed file — playlist position, approximate playing time and bit rate
— is displayed.
Runtime control
On POSIX systems, ezstream offers limited runtime control via signals. By sending a signal
to the ezstream process, e.g. with the kill(1) utility, a certain action will be triggered.
SIGHUP
Rereads the playlist file after the track that is currently streamed. If the playlist
is not to be shuffled, ezstream attempts to find the previously streamed file and
continue with the one following it, or restarts from the beginning of the list
otherwise.
SIGUSR1
Skips the currently playing track and moves on to the next in playlist mode, or
restarts the current track when streaming a single file.
SIGUSR2
Triggers rereading of metadata for the stream by running the program or script
specified in <metadata_progname/> (see below.) This is the only meaningful signal when
streaming from standard input.
CONFIGURATION FILE SYNTAX
The ezstream utility uses a simple XML configuration file format. It has a tree-like
structure and is made up of XML elements. Of all the possible XML features, only regular
elements that contain text or other elements, and comments, appear in an ezstream
configuration file.
Each element in the configuration file consists of a start tag, its content and an end tag.
For example:
<filename>playlist.m3u</filename>
<!-- XML comments look like this. -->
XML CONFIGURATION
In this section, each available element is listed and described. Note that for this
purpose, elements are introduced in their short, i.e. empty form. In the configuration
file, they need to be used as start tag + content + end tag, like in the introductory
example shown above.
Root element
<ezstream />
(Mandatory.) The configuration file's root element. It contains all other
configuration elements.
Global configuration elements
Each of the global configuration elements have the <ezstream/> element as their parent.
<url />
(Mandatory.) Specifies the location and mount point of the Icecast server, to which the
stream will be sent. The content must be of the form http://server:port/mountpoint For
example:
<url>http://example.com:8000/stream.ogg</url>
<sourceuser />
(Optional.) Sets the source username for authentication with the Icecast server. The
default user (usually “source”) is used if this element is not provided.
<sourcepassword />
(Mandatory.) Sets the source password for authentication with the Icecast server.
<format />
(Mandatory.) This element has two different meanings, depending on whether re-encoding
is enabled or not. It specifies the output format of the stream if re-encoding is
enabled. Otherwise, it specifies the input format of all input files. Recognized and
supported values for output stream formats are VORBIS, MP3 and THEORA. Other values
will be ignored and cause ezstream to simply pass through the data, which may or may
not work.
<filename />
(Mandatory.) Set the path and name of a single media file, a playlist, the name of an
external program (see below), or the keyword stdin for streaming from standard input.
Playlists are recognized by their filename extension and end with either .m3u or .txt.
A playlist consists of filenames, one entry per line. Comments in playlists are
introduced by a ‘#’ sign at the beginning of a line and ignored by ezstream.
<playlist_program />
(Optional.) Set to 1 (one) to indicate that the file in <filename/> is actually an
executable program or script. If set to 0 (zero), <filename/> content is assumed to be
a media file, playlist file or the keyword stdin (the default).
See the SCRIPTING section for details on how the playlist program must behave.
<shuffle />
(Optional.) Set to 1 (one) to randomly shuffle the entries of the playlist specified in
<filename/>. Files are played sequentially if set to 0 (zero) or when the <shuffle/>
element is absent. This option will be ignored if <playlist_program/> is set to 1
(one.)
<metadata_progname />
(Optional.) Set the path and name of an executable program or script that should be
used by ezstream to set the metadata of the stream. The program is automatically
queried when a new track is streamed, or whenever the SIGUSR2 signal is received.
If the <metadata_progname/> element is present in the configuration, no attempts will
be made to read metadata from files that are being streamed. If this behavior is not
desired, it should be removed or commented out in the configuration file.
See the SCRIPTING section for details on how the metadata program must behave.
<metadata_format />
(Optional.) Set the format of the string that should be used for the ‘@M@’ placeholder
when setting metadata with an external program or script via <metadata_progname/>.
See the METADATA section for details on how metadata is handled by ezstream.
<stream_once />
Set to 1 (one) in order to stream the content of <filename/> only once, and to 0 (zero)
for continuous streaming (the default).
<reconnect_tries />
Set how many attempts should be made to reconnect to the Icecast server in case the
connection is interrupted. The default is to try indefinitely, which is equal to
setting this configuration option to 0 (zero).
<svrinfoname />
(Optional.) Set the name of the broadcast. Informational only.
<svrinfourl />
(Optional.) Set the URL of the web site associated with the broadcast. Informational
only.
<svrinfogenre />
(Optional.) Set the genre of the broadcast. Informational only, used for YP.
<svrinfodescription />
(Optional.) Set the description of the broadcast. Informational only, used for YP.
<svrinfobitrate />
(Optional.) Set the bit rate of the broadcast. This setting is also purely
informational and only used for YP. The value is set by the user and not ezstream, and
should match the bit rate of the stream.
<svrinfoquality />
(Optional.) Set the quality setting of an Ogg Vorbis broadcast. Informational only and
needs to be set by the user, used for YP.
<svrinfochannels />
(Optional.) Set the number of audio channels in the broadcast, e.g. 1 (one) for mono
or 2 for stereo. Informational only and needs to be set by the user, used for YP.
<svrinfosamplerate />
(Optional.) Set the sample rate of the broadcast. Informational only and needs to be
set by the user, used for YP.
<svrinfopublic />
(Optional.) Set to 1 (one) if the broadcast may be listed in a public YP directory. If
set to 0 (zero), the Icecast server will not submit this stream to a YP directory,
which is also the default if the <svrinfopublic/> element is absent.
<reencode />
(Optional.) Element that contains child elements, which specify if and how re-encoding
should be done.
Re-encoding settings
Each of the re-encoding configuration elements have the <reencode/> element as their parent.
<enable />
Set to 1 (one) to enable re-encoding. If set to 0 (zero), no re-encoding will be done,
which is also the default if the <enable/> element is absent.
<encdec />
Element that contains child elements, which specify how to decode and encode a certain
media file format for streaming. Each format is described by a separate <encdec/>
element.
Decoder/Encoder settings
Each of the decoder/encoder configuration elements have the <encdec/> element as their
parent.
<format />
This element is used by ezstream to find the appropriate encoder for the output stream
format specified in the <format/> element inside the global configuration. For
consistency reasons, it is recommended that this element is always supplied, even for
currently unsupported output formats, with content such as VORBIS, MP3, THEORA, FLAC,
et cetera.
<match />
Set the filename extension used to identify a given media file format. This allows
ezstream to find the appropriate decoder for a given file. Should be set to .mp3 for
MP3, .flac for FLAC, .ogg for Ogg Vorbis, and so on.
<decode />
Set the command to decode the specified media file format to raw data and send it to
standard output. During runtime, the placeholder ‘@T@’ is replaced with the name of
the media file, as it is specified in the <filename/> element or contained in a
playlist file. It should always be enclosed in quotes, to prevent problems with
filenames that contain whitespaces.
Metadata placeholders can be used in the <decode/> element as well, for combined
de-/encoder programs that produce data that can be streamed. See the METADATA section
for details on how metadata is handled by ezstream.
For example, to decode Ogg Vorbis files using the oggdec utility:
<decode>oggdec -R -o - "@T@"</decode>
<encode />
Set the command to encode raw data, received from standard input, to the specified
stream format.
Metadata placeholders can be used in the <encode/> element. For details about using
metadata in ezstream, see below in the METADATA section.
For example, to encode an Ogg Vorbis stream using the quality setting 1.5 with the
oggenc utility:
<encode>oggenc -r -q 1.5 -t "@M@" -</encode>
SCRIPTING
The ezstream utility provides hooks for externally controlled playlist and metadata
management. This is done by running external programs or scripts that need to behave in
ways explained here.
Common Rules
- The program must be an executable file.
- The program must write one line to standard output and exit.
- The program must not require arbitrary command line options to function. A wrapper
script must be used if there is no other way.
Playlist Programs
- The program must return only filenames, with one filename per execution.
- The program should not return an empty line unless ezstream is supposed to know that the
end of the playlist has been reached. This is significant when the <stream_once/>
option is enabled.
Metadata Programs
- The program must not return anything (just a newline character is okay) if it is called
by ezstream with a command line parameter that the program does not support.
- When called without command line parameters, the program should return a complete string
that should be used for metadata.
- When called with the command line parameter "artist", the program should return only the
artist information of the metadata. (Optional.)
- When called with the command line parameter "title", the program should return only the
title information of the metadata. (Optional.)
- The supplied metadata must be encoded in UTF-8.
METADATA
The main tool for handling metadata with ezstream is placeholders in decoder and encoder
commands that are replaced with real content during runtime. The tricky part is that one of
the placeholders has to be handled differently, depending on where the metadata comes from.
This section will explain each possible scenario.
Metadata Placeholders
@T@ Replaced with the media file name. Required in <decode/> and is available in
<metadata_format/>.
@M@ Replaced with a metadata string. See below for a detailed explanation. Available in
<decode/> and <encode/>.
@a@ Replaced with the artist information. Available in <decode/>, <encode/> and
<metadata_format/>.
@t@ Replaced with the title information. Available in <decode/>, <encode/> and
<metadata_format/>.
@s@ Replaced with the string returned by <metadata_progname/> when called without any
command line parameters. Available only in <metadata_format/>.
The @M@ Placeholder
While all other placeholders are simply replaced with whatever data they are associated
with, ‘@M@’ is context-sensitive. The logic used by ezstream is the following:
If ('@M@ is present')
If ('<metadata_progname/>' AND '<metadata_format/>')
Replace with format string result.
Else
If (NOT '<metadata_progname/>' AND '@t@ is present')
Replace with empty string.
else
Replace with generated metadata string.
Endif
Endif
Endif
The generated metadata string for ‘@M@’ is of the format “Artist - Title”, if both artist
and title information is available. If one of the two is missing, the available one is
displayed without a leading or trailing dash, e.g. just “Artist”. If neither artist nor
title are available, the name of the media file — without its file extension — is used.
Metadata Caveats
It is possible to generate strange results with odd combinations of placeholders, external
metadata programs and updates during runtime via SIGUSR2. If things start to become just
confusing, simplify.
Metadata updates during runtime are done with a relatively broken feature of libshout.
Additional metadata information that is already present in the stream sent via ezstream is
usually destroyed and replaced with the new data. It is not possible to properly discern
between artist and title information, which means that anything set with the SIGUSR2 feature
will continue to end up entirely in the "Title" field of a stream.
Of all possible Ogg-based streams, only Ogg Vorbis can have its metadata manipulated by
Icecast. Any attempt of ezstream to update other Ogg metadata is actually a no-op.
While ezstream tries to do its best with relaying metadata accurately to Icecast, and
subsequently the listeners, different codesets and locales can pose a problem. Especially
when streaming MP3 files, it may help to explicitly set a codeset to work with via the
LC_CTYPE environment variable, as ezstream assumes ID3v1 tags to be in the user's current
locale. Note that, even though support for different locales is provided by ezstream,
Icecast itself and the listening clients also have a say in the matter. The only way to
ensure consistent results with metadata in non-Ogg streams is to use the characters
available in the ISO-8859-1 codeset.
External encoders may put additional, and possibly artificial, restrictions on valid
characters in metadata.
FILES
/usr/share/doc/ezstream/examples Directory containing example configuration files for
various uses of ezstream, as well as example playlist and
metadata scripts.
SEE ALSO
ezstream-file.sh(1)
AUTHORS
ezstream was written by:
Ed Zaleski <oddsock@oddsock.org>
Moritz Grimm <mdgrimm@gmx.net>
This manual was written by Moritz Grimm.