1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>GstTypeFindFactory: GStreamer 1.0 Core Reference Manual</title> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="GStreamer 1.0 Core Reference Manual"> 8<link rel="up" href="libgstreamer.html" title="GStreamer Core Library"> 9<link rel="prev" href="gstreamer-GstTypeFind.html" title="GstTypefind"> 10<link rel="next" href="gstreamer-GstUri.html" title="GstUri"> 11<meta name="generator" content="GTK-Doc V1.28 (XML mode)"> 12<link rel="stylesheet" href="style.css" type="text/css"> 13</head> 14<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 15<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="5"><tr valign="middle"> 16<td width="100%" align="left" class="shortcuts"> 17<a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span> 18 <a href="#GstTypeFindFactory.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span> 19 <a href="#GstTypeFindFactory.object-hierarchy" class="shortcut">Object Hierarchy</a></span> 20</td> 21<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td> 22<td><a accesskey="u" href="libgstreamer.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td> 23<td><a accesskey="p" href="gstreamer-GstTypeFind.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td> 24<td><a accesskey="n" href="gstreamer-GstUri.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td> 25</tr></table> 26<div class="refentry"> 27<a name="GstTypeFindFactory"></a><div class="titlepage"></div> 28<div class="refnamediv"><table width="100%"><tr> 29<td valign="top"> 30<h2><span class="refentrytitle"><a name="GstTypeFindFactory.top_of_page"></a>GstTypeFindFactory</span></h2> 31<p>GstTypeFindFactory — Information about registered typefind functions</p> 32</td> 33<td class="gallery_image" valign="top" align="right"></td> 34</tr></table></div> 35<div class="refsect1"> 36<a name="GstTypeFindFactory.functions"></a><h2>Functions</h2> 37<div class="informaltable"><table class="informaltable" width="100%" border="0"> 38<colgroup> 39<col width="150px" class="functions_return"> 40<col class="functions_name"> 41</colgroup> 42<tbody> 43<tr> 44<td class="function_type"> 45<a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> * 46</td> 47<td class="function_name"> 48<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> <span class="c_punctuation">()</span> 49</td> 50</tr> 51<tr> 52<td class="function_type">const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> * const * 53</td> 54<td class="function_name"> 55<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> <span class="c_punctuation">()</span> 56</td> 57</tr> 58<tr> 59<td class="function_type"> 60<a class="link" href="GstCaps.html" title="GstCaps"><span class="returnvalue">GstCaps</span></a> * 61</td> 62<td class="function_name"> 63<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> <span class="c_punctuation">()</span> 64</td> 65</tr> 66<tr> 67<td class="function_type"> 68<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> 69</td> 70<td class="function_name"> 71<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> <span class="c_punctuation">()</span> 72</td> 73</tr> 74<tr> 75<td class="function_type"> 76<span class="returnvalue">void</span> 77</td> 78<td class="function_name"> 79<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> <span class="c_punctuation">()</span> 80</td> 81</tr> 82</tbody> 83</table></div> 84</div> 85<div class="refsect1"> 86<a name="GstTypeFindFactory.other"></a><h2>Types and Values</h2> 87<div class="informaltable"><table class="informaltable" width="100%" border="0"> 88<colgroup> 89<col width="150px" class="name"> 90<col class="description"> 91</colgroup> 92<tbody><tr> 93<td class="datatype_keyword"> </td> 94<td class="function_name"><a class="link" href="GstTypeFindFactory.html#GstTypeFindFactory-struct" title="GstTypeFindFactory">GstTypeFindFactory</a></td> 95</tr></tbody> 96</table></div> 97</div> 98<div class="refsect1"> 99<a name="GstTypeFindFactory.object-hierarchy"></a><h2>Object Hierarchy</h2> 100<pre class="screen"> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GObject-struct">GObject</a> 101 <span class="lineart">╰──</span> <a href="/usr/share/gtk-doc/html/gobject/gobject-The-Base-Object-Type.html#GInitiallyUnowned">GInitiallyUnowned</a> 102 <span class="lineart">╰──</span> <a class="link" href="GstObject.html" title="GstObject">GstObject</a> 103 <span class="lineart">╰──</span> <a class="link" href="GstPluginFeature.html" title="GstPluginfeature">GstPluginFeature</a> 104 <span class="lineart">╰──</span> GstTypeFindFactory 105</pre> 106</div> 107<div class="refsect1"> 108<a name="GstTypeFindFactory.includes"></a><h2>Includes</h2> 109<pre class="synopsis">#include <gst/gst.h> 110</pre> 111</div> 112<div class="refsect1"> 113<a name="GstTypeFindFactory.description"></a><h2>Description</h2> 114<p>These functions allow querying information about registered typefind 115functions. How to create and register these functions is described in 116the section <GTKDOCLINK HREF="gstreamer-Writing-typefind-functions"> 117"Writing typefind functions"</GTKDOCLINK>.</p> 118<p>The following example shows how to write a very simple typefinder that 119identifies the given data. You can get quite a bit more complicated than 120that though.</p> 121<div class="informalexample"> 122 <table class="listing_frame" border="0" cellpadding="0" cellspacing="0"> 123 <tbody> 124 <tr> 125 <td class="listing_lines" align="right"><pre>1 1262 1273 1284 1295 1306 1317 1328 1339 13410 13511 13612 13713 13814 13915 14016 14117 14218 14319 14420 14521 14622 14723 14824 14925 15026 15127 15228 15329 15430 15531 15632 15733 15834 15935 16036 16137 16238 16339</pre></td> 164 <td class="listing_code"><pre class="programlisting"><span class="gtkdoc kwc">typedef</span> <span class="gtkdoc kwb">struct</span> <span class="gtkdoc opt">{</span> 165 guint8 <span class="gtkdoc opt">*</span>data<span class="gtkdoc opt">;</span> 166 guint size<span class="gtkdoc opt">;</span> 167 guint probability<span class="gtkdoc opt">;</span> 168 GstCaps <span class="gtkdoc opt">*</span>data<span class="gtkdoc opt">;</span> 169<span class="gtkdoc opt">}</span> MyTypeFind<span class="gtkdoc opt">;</span> 170<span class="gtkdoc kwb">static void</span> 171<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> 172<span class="gtkdoc opt">{</span> 173 MyTypeFind <span class="gtkdoc opt">*</span>find <span class="gtkdoc opt">= (</span>MyTypeFind <span class="gtkdoc opt">*)</span> data<span class="gtkdoc opt">;</span> 174 <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> 175 <span class="keyword">return</span> find<span class="gtkdoc opt">-></span>data <span class="gtkdoc opt">+</span> offset<span class="gtkdoc opt">;</span> 176 <span class="gtkdoc opt">}</span> 177 <span class="keyword">return</span> NULL<span class="gtkdoc opt">;</span> 178<span class="gtkdoc opt">}</span> 179<span class="gtkdoc kwb">static void</span> 180<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> 181<span class="gtkdoc opt">{</span> 182 MyTypeFind <span class="gtkdoc opt">*</span>find <span class="gtkdoc opt">= (</span>MyTypeFind <span class="gtkdoc opt">*)</span> data<span class="gtkdoc opt">;</span> 183 <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> 184 find<span class="gtkdoc opt">-></span>probability <span class="gtkdoc opt">=</span> probability<span class="gtkdoc opt">;</span> 185 <span class="function"><a href="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> 186 <span class="gtkdoc opt">}</span> 187<span class="gtkdoc opt">}</span> 188<span class="gtkdoc kwb">static</span> GstCaps <span class="gtkdoc opt">*</span> 189<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> 190<span class="gtkdoc opt">{</span> 191 GList <span class="gtkdoc opt">*</span>walk<span class="gtkdoc opt">, *</span>type_list<span class="gtkdoc opt">;</span> 192 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> 193 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> 194 walk <span class="gtkdoc opt">=</span> type_list <span class="gtkdoc opt">=</span> <span class="function"><a href="GstTypeFindFactory.html#gst-type-find-factory-get-list">gst_type_find_factory_get_list</a></span> <span class="gtkdoc opt">();</span> 195 <span class="keyword">while</span> <span class="gtkdoc opt">(</span>walk<span class="gtkdoc opt">) {</span> 196 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> 197 walk <span class="gtkdoc opt">=</span> <span class="function"><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#g-list-next">g_list_next</a></span> <span class="gtkdoc opt">(</span>walk<span class="gtkdoc opt">)</span> 198 <span class="function"><a href="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> 199 <span class="gtkdoc opt">}</span> 200 <span class="function"><a href="/usr/share/gtk-doc/html/glib/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> 201 <span class="keyword">return</span> find<span class="gtkdoc opt">.</span>caps<span class="gtkdoc opt">;</span> 202<span class="gtkdoc opt">};</span></pre></td> 203 </tr> 204 </tbody> 205 </table> 206</div> 207 208<p></p> 209</div> 210<div class="refsect1"> 211<a name="GstTypeFindFactory.functions_details"></a><h2>Functions</h2> 212<div class="refsect2"> 213<a name="gst-type-find-factory-get-list"></a><h3>gst_type_find_factory_get_list ()</h3> 214<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#GList"><span class="returnvalue">GList</span></a> * 215gst_type_find_factory_get_list (<em class="parameter"><code><span class="type">void</span></code></em>);</pre> 216<p>Gets the list of all registered typefind factories. You must free the 217list 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> 218<p>The returned factories are sorted by highest rank first, and then by 219factory name.</p> 220<p>Free-function: gst_plugin_feature_list_free</p> 221<div class="refsect3"> 222<a name="gst-type-find-factory-get-list.returns"></a><h4>Returns</h4> 223<p>the list of all 224registered <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>. </p> 225<p><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></p> 226</div> 227</div> 228<hr> 229<div class="refsect2"> 230<a name="gst-type-find-factory-get-extensions"></a><h3>gst_type_find_factory_get_extensions ()</h3> 231<pre class="programlisting">const <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> * const * 232gst_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> 233<p>Gets the extensions associated with a <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a>. The returned 234array should not be changed. If you need to change stuff in it, you should 235copy it using <a href="/usr/share/gtk-doc/html/glib/glib-String-Utility-Functions.html#g-strdupv"><code class="function">g_strdupv()</code></a>. This function may return <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to indicate 236a 0-length list.</p> 237<div class="refsect3"> 238<a name="gst-type-find-factory-get-extensions.parameters"></a><h4>Parameters</h4> 239<div class="informaltable"><table class="informaltable" width="100%" border="0"> 240<colgroup> 241<col width="150px" class="parameters_name"> 242<col class="parameters_description"> 243<col width="200px" class="parameters_annotations"> 244</colgroup> 245<tbody><tr> 246<td class="parameter_name"><p>factory</p></td> 247<td class="parameter_description"><p>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a></p></td> 248<td class="parameter_annotations"> </td> 249</tr></tbody> 250</table></div> 251</div> 252<div class="refsect3"> 253<a name="gst-type-find-factory-get-extensions.returns"></a><h4>Returns</h4> 254<p>a <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated array of extensions associated with this factory. </p> 255<p><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][<acronym title="NULL may be passed as the value in, out, in-out; or as a return value."><span class="acronym">nullable</span></acronym>]</span></p> 256</div> 257</div> 258<hr> 259<div class="refsect2"> 260<a name="gst-type-find-factory-get-caps"></a><h3>gst_type_find_factory_get_caps ()</h3> 261<pre class="programlisting"><a class="link" href="GstCaps.html" title="GstCaps"><span class="returnvalue">GstCaps</span></a> * 262gst_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> 263<p>Gets the <a class="link" href="GstCaps.html" title="GstCaps"><span class="type">GstCaps</span></a> associated with a typefind factory.</p> 264<div class="refsect3"> 265<a name="gst-type-find-factory-get-caps.parameters"></a><h4>Parameters</h4> 266<div class="informaltable"><table class="informaltable" width="100%" border="0"> 267<colgroup> 268<col width="150px" class="parameters_name"> 269<col class="parameters_description"> 270<col width="200px" class="parameters_annotations"> 271</colgroup> 272<tbody><tr> 273<td class="parameter_name"><p>factory</p></td> 274<td class="parameter_description"><p>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a></p></td> 275<td class="parameter_annotations"> </td> 276</tr></tbody> 277</table></div> 278</div> 279<div class="refsect3"> 280<a name="gst-type-find-factory-get-caps.returns"></a><h4>Returns</h4> 281<p>the <a class="link" href="GstCaps.html" title="GstCaps"><span class="type">GstCaps</span></a> associated with this factory. </p> 282<p><span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span></p> 283</div> 284</div> 285<hr> 286<div class="refsect2"> 287<a name="gst-type-find-factory-has-function"></a><h3>gst_type_find_factory_has_function ()</h3> 288<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> 289gst_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> 290<p>Check whether the factory has a typefind function. Typefind factories 291without typefind functions are a last-effort fallback mechanism to 292e.g. assume a certain media type based on the file extension.</p> 293<div class="refsect3"> 294<a name="gst-type-find-factory-has-function.parameters"></a><h4>Parameters</h4> 295<div class="informaltable"><table class="informaltable" width="100%" border="0"> 296<colgroup> 297<col width="150px" class="parameters_name"> 298<col class="parameters_description"> 299<col width="200px" class="parameters_annotations"> 300</colgroup> 301<tbody><tr> 302<td class="parameter_name"><p>factory</p></td> 303<td class="parameter_description"><p>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a></p></td> 304<td class="parameter_annotations"> </td> 305</tr></tbody> 306</table></div> 307</div> 308<div class="refsect3"> 309<a name="gst-type-find-factory-has-function.returns"></a><h4>Returns</h4> 310<p> <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the factory has a typefind functions set, otherwise <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a></p> 311</div> 312</div> 313<hr> 314<div class="refsect2"> 315<a name="gst-type-find-factory-call-function"></a><h3>gst_type_find_factory_call_function ()</h3> 316<pre class="programlisting"><span class="returnvalue">void</span> 317gst_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>, 318 <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> 319<p>Calls the <a class="link" href="gstreamer-GstTypeFind.html#GstTypeFindFunction" title="GstTypeFindFunction ()"><span class="type">GstTypeFindFunction</span></a> associated with this factory.</p> 320<div class="refsect3"> 321<a name="gst-type-find-factory-call-function.parameters"></a><h4>Parameters</h4> 322<div class="informaltable"><table class="informaltable" width="100%" border="0"> 323<colgroup> 324<col width="150px" class="parameters_name"> 325<col class="parameters_description"> 326<col width="200px" class="parameters_annotations"> 327</colgroup> 328<tbody> 329<tr> 330<td class="parameter_name"><p>factory</p></td> 331<td class="parameter_description"><p>A <a class="link" href="GstTypeFindFactory.html" title="GstTypeFindFactory"><span class="type">GstTypeFindFactory</span></a></p></td> 332<td class="parameter_annotations"> </td> 333</tr> 334<tr> 335<td class="parameter_name"><p>find</p></td> 336<td class="parameter_description"><p>a properly setup <a class="link" href="gstreamer-GstTypeFind.html#GstTypeFind" title="struct GstTypeFind"><span class="type">GstTypeFind</span></a> entry. The get_data 337and suggest_type members must be set. </p></td> 338<td class="parameter_annotations"><span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span></td> 339</tr> 340</tbody> 341</table></div> 342</div> 343</div> 344</div> 345<div class="refsect1"> 346<a name="GstTypeFindFactory.other_details"></a><h2>Types and Values</h2> 347<div class="refsect2"> 348<a name="GstTypeFindFactory-struct"></a><h3>GstTypeFindFactory</h3> 349<pre class="programlisting">typedef struct _GstTypeFindFactory GstTypeFindFactory;</pre> 350<p>Opaque object that stores information about a typefind function.</p> 351</div> 352</div> 353</div> 354<div class="footer"> 355<hr>Generated by GTK-Doc V1.28</div> 356</body> 357</html>
