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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<a href="#GstTypeFindFactory.object-hierarchy" class="shortcut">Object Hierarchy</a>
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<div class="refentry">
<a name="GstTypeFindFactory"></a><div class="titlepage"></div>
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<td valign="top">
<h2><span class="refentrytitle"><a name="GstTypeFindFactory.top_of_page"></a>GstTypeFindFactory</span></h2>
<p>GstTypeFindFactory — Information about registered typefind functions</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="GstTypeFindFactory.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">
#include <gst/gst.h>
<a class="link" href="GstTypeFindFactory.html#GstTypeFindFactory-struct" title="GstTypeFindFactory">GstTypeFindFactory</a>;
<a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> * <a class="link" href="GstTypeFindFactory.html#gst-type-find-factory-get-list" title="gst_type_find_factory_get_list ()">gst_type_find_factory_get_list</a> (<em class="parameter"><code><span class="type">void</span></code></em>);
const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> * const * <a class="link" href="GstTypeFindFactory.html#gst-type-find-factory-get-extensions" title="gst_type_find_factory_get_extensions ()">gst_type_find_factory_get_extensions</a>
(<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);
<a class="link" href="gstreamer-GstCaps.html#GstCaps" title="struct GstCaps"><span class="returnvalue">GstCaps</span></a> * <a class="link" href="GstTypeFindFactory.html#gst-type-find-factory-get-caps" title="gst_type_find_factory_get_caps ()">gst_type_find_factory_get_caps</a> (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);
<a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="GstTypeFindFactory.html#gst-type-find-factory-has-function" title="gst_type_find_factory_has_function ()">gst_type_find_factory_has_function</a> (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);
<span class="returnvalue">void</span> <a class="link" href="GstTypeFindFactory.html#gst-type-find-factory-call-function" title="gst_type_find_factory_call_function ()">gst_type_find_factory_call_function</a> (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstTypeFind.html#GstTypeFind" title="struct GstTypeFind"><span class="type">GstTypeFind</span></a> *find</code></em>);
</pre>
</div>
<div class="refsect1">
<a name="GstTypeFindFactory.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="synopsis">
<a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject">GObject</a>
+----<a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a>
+----<a class="link" href="GstObject.html" title="GstObject">GstObject</a>
+----<a class="link" href="GstPluginFeature.html" title="GstPluginFeature">GstPluginFeature</a>
+----GstTypeFindFactory
</pre>
</div>
<div class="refsect1">
<a name="GstTypeFindFactory.description"></a><h2>Description</h2>
<p>
These functions allow querying informations about registered typefind
functions. How to create and register these functions is described in
the section <GTKDOCLINK HREF="gstreamer-Writing-typefind-functions">
"Writing typefind functions"</GTKDOCLINK>.
</p>
<p>
</p>
<div class="example">
<a name="idp78768448"></a><p class="title"><b>Example 13. how to write a simple typefinder</b></p>
<div class="example-contents">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
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39</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc kwc">typedef</span> <span class="gtkdoc kwb">struct</span> <span class="gtkdoc opt">{</span>
guint8 <span class="gtkdoc opt">*</span>data<span class="gtkdoc opt">;</span>
guint size<span class="gtkdoc opt">;</span>
guint probability<span class="gtkdoc opt">;</span>
GstCaps <span class="gtkdoc opt">*</span>data<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span> MyTypeFind<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">my_peek</span> <span class="gtkdoc opt">(</span>gpointer data<span class="gtkdoc opt">,</span> gint64 offset<span class="gtkdoc opt">,</span> guint size<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
MyTypeFind <span class="gtkdoc opt">*</span>find <span class="gtkdoc opt">= (</span>MyTypeFind <span class="gtkdoc opt">*)</span> data<span class="gtkdoc opt">;</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>offset <span class="gtkdoc opt">>=</span> <span class="number">0</span> <span class="gtkdoc opt">&&</span> offset <span class="gtkdoc opt">+</span> size <span class="gtkdoc opt"><=</span> find<span class="gtkdoc opt">-></span>size<span class="gtkdoc opt">) {</span>
<span class="keyword">return</span> find<span class="gtkdoc opt">-></span>data <span class="gtkdoc opt">+</span> offset<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">return</span> NULL<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">my_suggest</span> <span class="gtkdoc opt">(</span>gpointer data<span class="gtkdoc opt">,</span> guint probability<span class="gtkdoc opt">,</span> GstCaps <span class="gtkdoc opt">*</span>caps<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
MyTypeFind <span class="gtkdoc opt">*</span>find <span class="gtkdoc opt">= (</span>MyTypeFind <span class="gtkdoc opt">*)</span> data<span class="gtkdoc opt">;</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>probability <span class="gtkdoc opt">></span> find<span class="gtkdoc opt">-></span>probability<span class="gtkdoc opt">) {</span>
find<span class="gtkdoc opt">-></span>probability <span class="gtkdoc opt">=</span> probability<span class="gtkdoc opt">;</span>
<span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#gst-caps-replace">gst_caps_replace</a></span> <span class="gtkdoc opt">(&</span>find<span class="gtkdoc opt">-></span>caps<span class="gtkdoc opt">,</span> caps<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static</span> GstCaps <span class="gtkdoc opt">*</span>
<span class="function">find_type</span> <span class="gtkdoc opt">(</span>guint8 <span class="gtkdoc opt">*</span>data<span class="gtkdoc opt">,</span> guint size<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
GList <span class="gtkdoc opt">*</span>walk<span class="gtkdoc opt">, *</span>type_list<span class="gtkdoc opt">;</span>
MyTypeFind find <span class="gtkdoc opt">= {</span>data<span class="gtkdoc opt">,</span> size<span class="gtkdoc opt">,</span> <span class="number">0</span><span class="gtkdoc opt">,</span> NULL<span class="gtkdoc opt">};</span>
GstTypeFind gst_find <span class="gtkdoc opt">= {</span>my_peek<span class="gtkdoc opt">,</span> my_suggest<span class="gtkdoc opt">, &</span>find<span class="gtkdoc opt">, };</span>
walk <span class="gtkdoc opt">=</span> type_list <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstTypeFindFactory.html#gst-type-find-factory-get-list">gst_type_find_factory_get_list</a></span> <span class="gtkdoc opt">();</span>
<span class="keyword">while</span> <span class="gtkdoc opt">(</span>walk<span class="gtkdoc opt">) {</span>
GstTypeFindFactory <span class="gtkdoc opt">*</span>factory <span class="gtkdoc opt">=</span> <span class="function">GST_TYPE_FIND_FACTORY</span> <span class="gtkdoc opt">(</span>walk<span class="gtkdoc opt">-></span>data<span class="gtkdoc opt">);</span>
walk <span class="gtkdoc opt">=</span> <span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#g-list-next">g_list_next</a></span> <span class="gtkdoc opt">(</span>walk<span class="gtkdoc opt">)</span>
<span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstTypeFindFactory.html#gst-type-find-factory-call-function">gst_type_find_factory_call_function</a></span> <span class="gtkdoc opt">(</span>factory<span class="gtkdoc opt">, &</span>gst_find<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#g-list-free">g_list_free</a></span> <span class="gtkdoc opt">(</span>type_list<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> find<span class="gtkdoc opt">.</span>caps<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">};</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
<p><br class="example-break">
</p>
<p>
The above example shows how to write a very simple typefinder that
identifies the given data. You can get quite a bit more complicated than
that though.
</p>
<p>
Last reviewed on 2005-11-09 (0.9.4)
</p>
</div>
<div class="refsect1">
<a name="GstTypeFindFactory.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GstTypeFindFactory-struct"></a><h3>GstTypeFindFactory</h3>
<pre class="programlisting">typedef struct _GstTypeFindFactory GstTypeFindFactory;</pre>
<p>
Opaque object that stores information about a typefind function.
</p>
</div>
<hr>
<div class="refsect2">
<a name="gst-type-find-factory-get-list"></a><h3>gst_type_find_factory_get_list ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> * gst_type_find_factory_get_list (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
<p>
Gets the list of all registered typefind factories. You must free the
list using <a class="link" href="GstPluginFeature.html#gst-plugin-feature-list-free" title="gst_plugin_feature_list_free ()"><code class="function">gst_plugin_feature_list_free()</code></a>.
</p>
<p>
The returned factories are sorted by highest rank first, and then by
factory name.
</p>
<p>
Free-function: gst_plugin_feature_list_free
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>the list of all
registered <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<acronym title="Generics and defining elements of containers and arrays."><span class="acronym">element-type</span></acronym> Gst.TypeFindFactory]</span>
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-type-find-factory-get-extensions"></a><h3>gst_type_find_factory_get_extensions ()</h3>
<pre class="programlisting">const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> * const * gst_type_find_factory_get_extensions
(<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);</pre>
<p>
Gets the extensions associated with a <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>. The returned
array should not be changed. If you need to change stuff in it, you should
copy it using <a href="http://library.gnome.org/devel/glib/unstable/glib-String-Utility-Functions.html#g-strdupv"><code class="function">g_strdupv()</code></a>. This function may return NULL to indicate
a 0-length list.
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>factory</code></em> :</span></p></td>
<td>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>a
NULL-terminated array of extensions associated with this factory. <span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>][<acronym title="Parameter points to an array of items."><span class="acronym">array</span></acronym> zero-terminated=1][<acronym title="Generics and defining elements of containers and arrays."><span class="acronym">element-type</span></acronym> utf8]</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-type-find-factory-get-caps"></a><h3>gst_type_find_factory_get_caps ()</h3>
<pre class="programlisting"><a class="link" href="gstreamer-GstCaps.html#GstCaps" title="struct GstCaps"><span class="returnvalue">GstCaps</span></a> * gst_type_find_factory_get_caps (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);</pre>
<p>
Gets the <a class="link" href="gstreamer-GstCaps.html#GstCaps" title="struct GstCaps"><span class="type">GstCaps</span></a> associated with a typefind factory.
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>factory</code></em> :</span></p></td>
<td>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>the <a class="link" href="gstreamer-GstCaps.html#GstCaps" title="struct GstCaps"><span class="type">GstCaps</span></a> associated with this factory. <span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-type-find-factory-has-function"></a><h3>gst_type_find_factory_has_function ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_type_find_factory_has_function (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>);</pre>
<p>
Check whether the factory has a typefind function. Typefind factories
without typefind functions are a last-effort fallback mechanism to
e.g. assume a certain media type based on the file extension.
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>factory</code></em> :</span></p></td>
<td>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>TRUE if the factory has a typefind functions set, otherwise FALSE</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-type-find-factory-call-function"></a><h3>gst_type_find_factory_call_function ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_type_find_factory_call_function (<em class="parameter"><code><a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a> *factory</code></em>,
<em class="parameter"><code><a class="link" href="gstreamer-GstTypeFind.html#GstTypeFind" title="struct GstTypeFind"><span class="type">GstTypeFind</span></a> *find</code></em>);</pre>
<p>
Calls the <a class="link" href="gstreamer-GstTypeFind.html#GstTypeFindFunction" title="GstTypeFindFunction ()"><span class="type">GstTypeFindFunction</span></a> associated with this factory.
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>factory</code></em> :</span></p></td>
<td>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>find</code></em> :</span></p></td>
<td>a properly setup <a class="link" href="gstreamer-GstTypeFind.html#GstTypeFind" title="struct GstTypeFind"><span class="type">GstTypeFind</span></a> entry. The get_data
and suggest_type members must be set. <span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span>
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