"http://docbook.org/xml/4.2/docbookx.dtd">

<book><title>Programming With Libshout 2</title>

  <bookinfo>

    <author>

      <firstname>Brendan</firstname><surname>Cully</surname>

      <email>brendan@xiph.org</email>

    </author>

    <copyright>

      <year>2003</year>

      <holder>Brendan Cully</holder>

    </copyright>

    -->

    <orgname><ulink url="http://xiph.org/">Xiph.org</ulink></orgname>

    <releaseinfo>$Id: libshout.xml 7019 2004-07-06 08:05:47Z brendan $</releaseinfo>

    <date> 3 Jul 2003</date>

  </bookinfo>

<chapter><title>Overview</title>

<para>

libshout is a library for streaming audio to icecast or shoutcast-compatible

servers. Currently it supports two audio formats and three protocols.

</para>

<itemizedlist><title>Audio Formats</title>

  <listitem>Ogg Vorbis</listitem>

  <listitem>MP3</listitem>

</itemizedlist>

<itemizedlist><title>Protocols</title>

  <listitem>HTTP</listitem>

  <listitem>Audiocast</listitem>

  <listitem>ShoutCast</listitem>

</itemizedlist>

</chapter>

<chapter><title>Reference</title>

<section><title>Functions</title>

<section><title>Global functions</title>

<funcsynopsis id="shout_init">

<funcprototype>

  <funcdef>void <function>shout_init</function></funcdef>

  <void/>

</funcprototype>

</funcsynopsis>

Initializes the shout library. Currently this initializes the networking

mutexes when the library is built with thread safety. This function must

always be called before any other libshout function.

<funcsynopsis id="shout_shutdown">

<funcprototype>

  <funcdef>void <function>shout_shutdown</function></funcdef>

  <void/>

</funcprototype>

</funcsynopsis>

Releases any resources which may have been allocated by a call to

<link linkend="shout_init"><function>shout_init</function></link>. An

application should call this function after it has finished using libshout.

<funcsynopsis id="shout_version">

<funcprototype>

  <funcdef>const char *<function>shout_version</function></funcdef>

  <paramdef>int *<parameter>major</parameter></paramdef>

  <paramdef>int *<parameter>minor</parameter></paramdef>

  <paramdef>int *<parameter>patch</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the version of the libshout library, both as a string via the

return value, and as a set of integers corresponding to the major,

minor and patch levels of the library. The application must allocate

the integer parameters. If any parameter is NULL, libshout will not

attempt to set it.

</section>

<section><title>Managing connections</title>

<funcsynopsis id="shout_new">

<funcprototype>

  <funcdef><type>shout_t</type> *<function>shout_new</function></funcdef>

  <void/>

</funcprototype>

</funcsynopsis>

Allocates a new <type>shout_t</type> structure. May return NULL if no memory

is available. The result should be disposed of with

<link linkend="shout_free"><function>shout_free</function></link> when you are

finished with it.

<funcsynopsis id="shout_free">

<funcprototype>

  <funcdef>void <function>shout_free</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Frees a <type>shout_t</type> allocated by

<link linkend="shout_new"><function>shout_new</function></link>.

<funcsynopsis id="shout_open">

<funcprototype>

  <funcdef>int <function>shout_open</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Opens a connection to a server. All connection parameters must have been

set prior to this call.

<variablelist><title>Return Values</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>The connection was successfully opened.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> is corrupt or incorrect. Possible reasons

  include an unset host, port, or password.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_CONNECTED</constant></term>

  <listitem>The connection has already been opened.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNSUPPORTED</constant></term>

  <listitem>The protocol/format combination is unsupported. For instance,

  Ogg Vorbis may only be sent via the HTTP protocol.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOCONNECT</constant></term>

  <listitem>A connection to the server could not be established.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_SOCKET</constant></term>

  <listitem>An error occured while talking to the server.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOLOGIN</constant></term>

  <listitem>The server refused login, probably because authentication

  failed.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_MALLOC</constant></term>

  <listitem>There wasn't enough memory to complete the operation.</listitem>

  </varlistentry>

</variablelist>

<funcsynopsis id="shout_close">

<funcprototype>

  <funcdef>int <function>shout_close</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Closes a connection to the server.

<variablelist><title>Return Values</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>The connection was successfully closed.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> is not a valid <type>shout_t</type>

  object.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNCONNECTED</constant></term>

  <listitem><varname>self</varname> is not currently connected.</listitem>

  </varlistentry>

</variablelist>

<funcsynopsis id="shout_get_error">

<funcprototype>

  <funcdef>const char *<function>shout_get_error</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns a statically allocated string describing the last shout error

that occured in this connection. Only valid until the next call affecting

this connection.

<funcsynopsis id="shout_get_errno">

<funcprototype>

  <funcdef>int <function>shout_get_errno</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the shout error code of the last error that occured in this connection.

</section>

<section><title>Sending data</title>

<funcsynopsis id="shout_send">

<funcprototype>

  <funcdef>int <function>shout_send</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const unsigned char *<parameter>data></parameter></paramdef>

  <paramdef><type>size_t</type> <parameter>len</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sends <varname>len</varname> bytes of audio data from the buffer pointed to by

<varname>data</varname> to the server. The connection must already have been

established by a successful call to

<link linkend="shout_open"><function>shout_open</function></link>.

<variablelist><title>Return Values</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>The audio data was sent successfully.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> is not a valid <type>shout_t</type>

  object.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNCONNECTED</constant></term>

  <listitem><varname>self</varname> is not currently connected.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_MALLOC</constant></term>

  <listitem>There wasn't enough memory to complete the operation.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_SOCKET</constant></term>

  <listitem>An error occured while talking to the server.</listitem>

  </varlistentry>

</variablelist>

<funcsynopsis id="shout_send_raw">

<funcprototype>

  <funcdef><type>ssize_t</type> <function>shout_send_raw</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const unsigned char *<parameter>data></parameter></paramdef>

  <paramdef><type>size_t</type> <parameter>len</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sends <varname>len</varname> bytes of audio data from the buffer pointed to by

<varname>data</varname> to the server. The data is not parsed for timing

or validity, but sent raw over the connection. The connection must already have been

established by a successful call to

<link linkend="shout_open"><function>shout_open</function></link>.

<warning>This function should not be used unless you know exactly what you

are doing. Its use is deprecated and it may be removed in a future version of

the library.</warning>

<variablelist><title>Return Values</title>

  <varlistentry>

  <term>>= 0</term>

  <listitem>The number of bytes written.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> is not a valid <type>shout_t</type>

  object.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNCONNECTED</constant></term>

  <listitem><varname>self</varname> is not currently connected.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_SOCKET</constant></term>

  <listitem>An error occured while talking to the server.</listitem>

  </varlistentry>

</variablelist>

<funcsynopsis id="shout_sync">

<funcprototype>

  <funcdef>void <function>shout_sync</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Causes the caller to sleep for the amount of time necessary to play back

audio sent since the last call to <function>shout_sync</function>. Should

be called before every call to

<link linkend="shout_send"><function>shout_send</function></link> to

ensure that audio data is sent to the server at the correct speed.

Alternatively, the caller may use

<link linkend="shout_delay"><function>shout_delay</function></link> to

determine the number of milliseconds to wait and delay itself.

<funcsynopsis id="shout_delay">

<funcprototype>

  <funcdef>int <function>shout_delay</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the number of milliseconds the caller should wait before calling

<link linkend="shout_send"><function>shout_send</function></link> again.

This function is provided as an alternative to

<link linkend="shout_sync"><function>shout_sync</function></link> for

applications that may wish to do other processing in the meantime.

</section>

<section><title>Connection parameters</title>

The following functions are used to get or set attributes of the

<type>shout_t</type> object before calling

<link linkend="shout_open"><function>shout_open</function></link>.  They all

work the same way: they operate on one attribute of a

<type>shout_t</type>*.  The <function>shout_get_*</function> functions

return the value of their associated parameter, or 0 on error (that's

NULL for those functions that return strings). The

<function>shout_set_*</function> functions will return either

<constant>SHOUTERR_SUCCESS</constant> on success, or one of:

<itemizedlist>

  <listitem><constant>SHOUTERR_INSANE</constant> - <type>shout_t</type>

  is invalid.</listitem>

  <listitem><constant>SHOUTERR_MALLOC</constant> - libshout could not

  allocate enough memory to assign the parameter.</listitem>

  <listitem><constant>SHOUTERR_CONNECTED</constant> - you are attempting

  to change a connection attribute while the connection is open. Since these

  parameters are only used when first opening the connection, this operation

  would be useless.</listitem>

</itemizedlist>

<funcsynopsis id="shout_set_host">

<funcprototype>

  <funcdef>int <function>shout_set_host</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>host</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the server hostname or IP address. The default is <constant>localhost</constant>.

<funcsynopsis id="shout_get_host">

<funcprototype>

  <funcdef>const char *<function>shout_get_host</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the server hostname or IP address.

<funcsynopsis id="shout_set_port">

<funcprototype>

  <funcdef>int <function>shout_set_port</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>int <parameter>port</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the server port. The default is <constant>8000</constant>.

<funcsynopsis id="shout_get_port">

<funcprototype>

  <funcdef>int <function>shout_get_port</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the server port.

<funcsynopsis id="shout_set_user">

<funcprototype>

  <funcdef>int <function>shout_set_user</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>user</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the user to authenticate as, for protocols that can use this parameter.

The default is <constant>source</constant>.

<funcsynopsis id="shout_get_user">

<funcprototype>

  <funcdef>const char *<function>shout_get_user</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the user name.

<funcsynopsis id="shout_set_pass">

<funcprototype>

  <funcdef>int <function>shout_set_pass</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>pass</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the password to authenticate to the server with. This parameter

<emphasis>must</emphasis> be set. There is no default.

<funcsynopsis id="shout_get_pass">

<funcprototype>

  <funcdef>const char *<function>shout_get_pass</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the password.

<funcsynopsis id="shout_set_protocol">

<funcprototype>

  <funcdef>int <function>shout_set_protocol</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>int <parameter>protocol</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Set the protocol with which to connect to the server. Supported protocols

are listed in <link linkend="protocol_constants">Protocol Constants</link>.

The default is <constant>SHOUT_PROTOCOL_HTTP</constant> (compatible with

Icecast 2).

<funcsynopsis id="shout_get_protocol">

<funcprototype>

  <funcdef>int <function>shout_get_protocol</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the protocol used to connect to the server.

<funcsynopsis id="shout_set_format">

<funcprototype>

  <funcdef>int <function>shout_set_format</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>int <parameter>format</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the audio format of this stream. The currently supported formats

are listed in <link linkend="format_constants">Format Constants</link>.

The default is <constant>SHOUT_FORMAT_VORBIS</constant>.

<funcsynopsis id="shout_get_format">

<funcprototype>

  <funcdef>int <function>shout_get_format</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the audio format used by this stream.

<funcsynopsis id="shout_set_mount">

<funcprototype>

  <funcdef>int <function>shout_set_mount</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>mount</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the mount point for this stream, for protocols that support this option

(<constant>SHOUT_PROTOCOL_ICY</constant> doesn't).

<funcsynopsis id="shout_get_mount">

<funcprototype>

  <funcdef>const char *<function>shout_get_mount</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the stream mount point.

<funcsynopsis id="shout_set_dumpfile">

<funcprototype>

  <funcdef>int <function>shout_set_dumpfile</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>dumpfile</parameter></paramdef>

</funcprototype>

</funcsynopsis>

If the server supports it, you can request that your stream be archived

on the server under the name <varname>dumpfile</varname>. This can quickly

eat a lot of disk space, so think twice before setting it.

<funcsynopsis id="shout_get_dumpfile">

<funcprototype>

  <funcdef>const char *<function>shout_get_dumpfile</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the dump file, if specified.

<funcsynopsis id="shout_set_agent">

<funcprototype>

  <funcdef>int <function>shout_set_agent</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>agent</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the user agent header. This is <constant>libshout/VERSION</constant>

by default. If you don't know what this function is for, don't use it.

<funcsynopsis id="shout_get_agent">

<funcprototype>

  <funcdef>const char *<function>shout_get_agent</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the user agent.

<section><title>Directory parameters</title>

The following parameters are optional. They are used to control whether

and how your stream will be listed in the server's stream directory (if available).

<funcsynopsis id="shout_set_public">

<funcprototype>

  <funcdef>int <function>shout_set_public</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>int <parameter>makepublic</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Setting this to <constant>1</constant> asks the server to list the stream in

any directories it knows about. To suppress listing, set this to

<constant>0</constant>. The default is <constant>0</constant>.

<funcsynopsis id="shout_get_public">

<funcprototype>

  <funcdef>int <function>shout_get_public</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns whether or not this stream is public.

<funcsynopsis id="shout_set_name">

<funcprototype>

  <funcdef>int <function>shout_set_name</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>name</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the name of the stream.

<funcsynopsis id="shout_get_name">

<funcprototype>

  <funcdef>const char *<function>shout_get_name</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the stream name.

<funcsynopsis id="shout_set_url">

<funcprototype>

  <funcdef>int <function>shout_set_url</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>url</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the URL of a site about this stream.

<funcsynopsis id="shout_get_url">

<funcprototype>

  <funcdef>const char *<function>shout_get_url</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the stream URL.

<funcsynopsis id="shout_set_genre">

<funcprototype>

  <funcdef>int <function>shout_set_genre</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>genre</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the genre (or genres) of the stream. This is usually a keyword list,

eg "pop rock rap".

<funcsynopsis id="shout_get_genre">

<funcprototype>

  <funcdef>const char *<function>shout_get_genre</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the stream genre.

<funcsynopsis id="shout_set_description">

<funcprototype>

  <funcdef>int <function>shout_set_description</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>description</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets the description of this stream.

<funcsynopsis id="shout_get_description">

<funcprototype>

  <funcdef>const char *<function>shout_get_description</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the stream description.

<funcsynopsis id="shout_set_audio_info">

<funcprototype>

  <funcdef>int <function>shout_set_audio_info</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>name</parameter></paramdef>

  <paramdef>const char *<parameter>value</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets a stream audio parameter (eg bitrate, samplerate, channels or quality).

The currently defined parameters are listed in the

<link linkend="audio_info_constants">Audio Info Constants</link> section, but

you are free to add additional fields if your directory server understands them.

<funcsynopsis id="shout_get_audio_info">

<funcprototype>

  <funcdef>const char *<function>shout_get_audio_info</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>name</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Returns the value of the audio info field <varname>name</varname>, if defined.

</section>

</section>

<section><title>Metadata</title>

These functions currently only make sense for MP3 streams. Vorbis streams are expected

to embed metadata as vorbis comments in the audio stream.

<funcsynopsis id="shout_metadata_new">

<funcprototype>

  <funcdef><type>shout_metadata_t</type> *<function>shout_metadata_new</function></funcdef>

  <void/>

</funcprototype>

</funcsynopsis>

Allocates a new metadata structure, or returns NULL if no memory is available. The

returned structure should be freed with

<link linkend="shout_metadata_free">shout_metadata_free</link> when you are done with

it.

<funcsynopsis id="shout_metadata_free">

<funcprototype>

  <funcdef>void <function>shout_metadata_free</function></funcdef>

  <paramdef><type>shout_metadata_t</type> *<parameter>self</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Frees any resources associated with <varname>self</varname>.

<funcsynopsis id="shout_metadata_add">

<funcprototype>

  <funcdef>int <function>shout_metadata_add</function></funcdef>

  <paramdef><type>shout_metadata_t</type> *<parameter>self</parameter></paramdef>

  <paramdef>const char *<parameter>name</parameter></paramdef>

  <paramdef>const char *<parameter>value</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Add metadata value <varname>value</varname> to <varname>self</varname>, under the

key <varname>name</varname>. You'll probably want to set <varname>name</varname>

to <constant>"song"</constant>, though <constant>"url"</constant> may also be

useful.

<variablelist><title>Return Values</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>The metadata was copied into <varname>self</varname>.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> is not a valid <type>shout_metadata_t</type> object.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_MALLOC</constant></term>

  <listitem>Couldn't allocate enough memory to copy the metadata.</listitem>

  </varlistentry>

</variablelist>

<funcsynopsis id="shout_set_metadata">

<funcprototype>

  <funcdef>int <function>shout_set_metadata</function></funcdef>

  <paramdef><type>shout_t</type> *<parameter>self</parameter></paramdef>

  <paramdef><type>shout_metadata_t</type> *<parameter>metadata</parameter></paramdef>

</funcprototype>

</funcsynopsis>

Sets metadata on the connection <varname>self</varname> to <varname>metadata</varname>.

Only MP3 streams support this type of metadata update. You may use this function

on defined but closed connections (this is useful if you simply want to set the

metadata for a stream provided by another process).

<variablelist><title>Return Values</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>Metadata was updated successfully.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem><varname>self</varname> and/or <varname>metadata</varname> is invalid.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_MALLOC</constant></term>

  <listitem>Couldn't allocate enough memory to complete the operation.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOCONNECT</constant></term>

  <listitem>The server refused the connection attempt.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOLOGIN</constant></term>

  <listitem>The server did not accept your authorization credentials.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_SOCKET</constant></term>

  <listitem>An error occured talking to the server.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_METADATA</constant></term>

  <listitem>The server returned any other error (eg bad mount point).</listitem>

  </varlistentry>

</variablelist>

</section>

</section>

<section><title>Data Types</title>

<variablelist id="data_types">

  <varlistentry id="shout_t">

  <term><type>shout_t</type></term>

  <listitem>Opaque data type that refers to a single server connection.</listitem>

  </varlistentry>

  <varlistentry id="shout_metadata_t">

  <term><type>shout_metadata_t</type></term>

  <listitem>Opaque data type that refers to a set of metadata attributes. Currently

  the only defined attribute is <constant>song</constant>.</listitem>

  </varlistentry>

</variablelist>

</section>

<section><title>Constants</title>

<variablelist id="error_constants"><title>Error Codes</title>

  <varlistentry>

  <term><constant>SHOUTERR_SUCCESS</constant></term>

  <listitem>Indicates success.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_INSANE</constant></term>

  <listitem>Indicates bad parameters, either nonsense or not applicable due to the current

  state of the connection.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_MALLOC</constant></term>

  <listitem>Indicates the function could not allocate the memory it required.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOCONNECT</constant></term>

  <listitem>Indicates a connection with the server could not be established.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_NOLOGIN</constant></term>

  <listitem>Indicates the server refused to accept a login attempt. This could be caused

  by a bad user name or password.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_SOCKET</constant></term>

  <listitem>Indicates an error sending or receiving data.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_METADATA</constant></term>

  <listitem>Indicates an error updating metadata on the server.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_CONNECTED</constant></term>

  <listitem>Indicates that, while connected, you attempted to call a function which only makes

  sense before connection (eg you attempted to set the user name or stream name).</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNCONNECTED</constant></term>

  <listitem>Indicates that you attempted to use a function that requires an open connection

  (for example, <function>shout_send</function>) while you were not connected.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUTERR_UNSUPPORTED</constant></term>

  <listitem>Indicates that you attempted to use a function which is unsupported in the

  state of your connection. For example, attempting to set metadata while using the

  Ogg Vorbis format is unsupported.</listitem>

  </varlistentry>

</variablelist>

<variablelist id="format_constants"><title>Formats</title>

  <varlistentry>

  <term><constant>SHOUT_FORMAT_VORBIS</constant></term>

  <listitem>The Ogg Vorbis format. This is the default format.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_FORMAT_MP3</constant></term>

  <listitem>The MP3 format.</listitem>

  </varlistentry>

</variablelist>

<variablelist id="protocol_constants"><title>Protocols</title>

  <varlistentry>

  <term><constant>SHOUT_PROTOCOL_HTTP</constant></term>

  <listitem>The HTTP protocol. This is the native protocol of the

  <application>icecast 2</application> server, and is the default.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_PROTOCOL_XAUDIOCAST</constant></term>

  <listitem>The Audiocast format. This is the native protocol of

  <application>icecast 1</application>.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_PROTOCOL_ICY</constant></term>

  <listitem>The ShoutCast format. This is the native protocol of

  <application>ShoutCast</application>.</listitem>

  </varlistentry>

</variablelist>

<variablelist id="audio_info_constants"><title>Audio Parameters</title>

  <varlistentry>

  <term><constant>SHOUT_AI_BITRATE</constant></term>

  <listitem>Used to specify the nominal bitrate of the stream.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_AI_SAMPLERATE</constant></term>

  <listitem>Used to specify the samplerate of the stream.</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_AI_CHANNELS</constant></term>

  <listitem>Used to specify the number of channels (usually one or two).</listitem>

  </varlistentry>

  <varlistentry>

  <term><constant>SHOUT_AI_QUALITY</constant></term>

  <listitem>Used to specify the Ogg Vorbis encoding quality of the stream.</listitem>

  </varlistentry>

</variablelist>

</section>

</chapter>

</book>