filters.sgml

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<refentry id="mediastreamer-Filters">
<refmeta>
<refentrytitle>MSFilters</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>MEDIASTREAMER Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>MSFilters</refname><refpurpose>The basic mediastreamer element.</refpurpose>
</refnamediv>

<refsynopsisdiv><title>Synopsis</title>

<synopsis>

#include &lt;msfilter.h&gt;


            <link linkend="MSFilter">MSFilter</link>;
<link linkend="int">int</link>         <link linkend="ms-filter-add-link">ms_filter_add_link</link>              (<link linkend="MSFilter">MSFilter</link> *m1,
                                             <link linkend="MSFilter">MSFilter</link> *m2);
</synopsis>
</refsynopsisdiv>









<refsect1>
<title>Description</title>
<para>
MSFilter is the base class for all mediastreamer processing filters: codec compression, soundcard read, souncard write, etc...
MSFilter objects have to be linked between them to form a processing chain, that is then attached to a MSSync object (synchronisation source)
in order to be scheduled for processing.
</para>
</refsect1>

<refsect1>
<title>Details</title>
<refsect2>
<title><anchor id="MSFilter">MSFilter</title>
<indexterm><primary>MSFilter</primary></indexterm><programlisting>typedef struct {
	struct _MSFilterClass *klass;
	GMutex *lock;
	guchar finputs;   /* number of connected fifo inputs*/
	guchar foutputs;  /* number of connected fifo outputs*/
	guchar qinputs;   /* number of connected queue inputs*/
	guchar qoutputs;  /* number of connected queue outputs*/
	gint min_fifo_size; /* set when linking*/
	gint r_mingran;				/* read minimum granularity (for fifos).
					It can be zero so that the filter can accept any size of reading data*/
	MSFifo **infifos; /*pointer to a table of pointer to input fifos*/
	MSFifo **outfifos;  /*pointer to a table of pointer to output fifos*/
	MSQueue **inqueues;  /*pointer to a table of pointer to input queues*/
	MSQueue **outqueues;  /*pointer to a table of pointer to output queues*/
	MSFilterNotifyFunc notify_event;
	gpointer userdata;
} MSFilter;
</programlisting>
<para>
Only programmers implementing derivated objects of MSFilter are interested by the content of the structure.
</para><variablelist role="struct">
<varlistentry>
<term>struct&nbsp;<link linkend="MSFilterClass">_MSFilterClass</link>&nbsp;*<structfield>klass</structfield>;</term>
<listitem><simpara>Pointer to the class structure.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="GMutex">GMutex</link>&nbsp;*<structfield>lock</structfield>;</term>
<listitem><simpara>
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guchar">guchar</link>&nbsp;<structfield>finputs</structfield>;</term>
<listitem><simpara> Number of fifo inputs currently in use.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guchar">guchar</link>&nbsp;<structfield>foutputs</structfield>;</term>
<listitem><simpara> Number of fifo outputs currently in use.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guchar">guchar</link>&nbsp;<structfield>qinputs</structfield>;</term>
<listitem><simpara>  Number of queue inputs currently in use.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="guchar">guchar</link>&nbsp;<structfield>qoutputs</structfield>;</term>
<listitem><simpara> Number of queue outputs currently in use.
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="gint">gint</link>&nbsp;<structfield>min_fifo_size</structfield>;</term>
<listitem><simpara>
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="gint">gint</link>&nbsp;<structfield>r_mingran</structfield>;</term>
<listitem><simpara>
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="MSFifo">MSFifo</link>&nbsp;**<structfield>infifos</structfield>;</term>
<listitem><simpara>  Pointer to a table of fifo inputs
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="MSFifo">MSFifo</link>&nbsp;**<structfield>outfifos</structfield>;</term>
<listitem><simpara> Pointer to a table of ffo ouputs
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="MSQueue">MSQueue</link>&nbsp;**<structfield>inqueues</structfield>;</term>
<listitem><simpara> Pointer to a table of queue inputs
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="MSQueue">MSQueue</link>&nbsp;**<structfield>outqueues</structfield>;</term>
<listitem><simpara>Pointer to a table of queue qoutputs
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="MSFilterNotifyFunc">MSFilterNotifyFunc</link>&nbsp;<structfield>notify_event</structfield>;</term>
<listitem><simpara>
</simpara></listitem>
</varlistentry>
<varlistentry>
<term><link linkend="gpointer">gpointer</link>&nbsp;<structfield>userdata</structfield>;</term>
<listitem><simpara>

</simpara></listitem>
</varlistentry>
</variablelist></refsect2>
<refsect2>
<title><anchor id="ms-filter-add-link">ms_filter_add_link ()</title>
<indexterm><primary>ms_filter_add_link</primary></indexterm><programlisting><link linkend="int">int</link>         ms_filter_add_link              (<link linkend="MSFilter">MSFilter</link> *m1,
                                             <link linkend="MSFilter">MSFilter</link> *m2);</programlisting>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>m1</parameter>&nbsp;:</term>
<listitem><simpara>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>m2</parameter>&nbsp;:</term>
<listitem><simpara>
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara>
</simpara></listitem></varlistentry>
</variablelist></refsect2>

</refsect1>




</refentry>