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  24 <a href="#gstreamer-libs-GstTypeFindHelper.synopsis" class="shortcut">Top</a>
  25                    |
  26                   <a href="#gstreamer-libs-GstTypeFindHelper.description" class="shortcut">Description</a>
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  29 <div class="refentry">
  30 <a name="gstreamer-libs-GstTypeFindHelper"></a><div class="titlepage"></div>
  31 <div class="refnamediv"><table width="100%"><tr>
  32 <td valign="top">
  33 <h2><span class="refentrytitle"><a name="gstreamer-libs-GstTypeFindHelper.top_of_page"></a>GstTypeFindHelper</span></h2>
  34 <p>GstTypeFindHelper — Utility functions for typefinding</p>
  35 </td>
  36 <td valign="top" align="right"></td>
  37 </tr></table></div>
  38 <div class="refsynopsisdiv">
  39 <a name="gstreamer-libs-GstTypeFindHelper.synopsis"></a><h2>Synopsis</h2>
  40 <pre class="synopsis">
  41 #include &lt;gst/base/gsttypefindhelper.h&gt;
  42
  43 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper" title="gst_type_find_helper ()">gst_type_find_helper</a>                (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a> *src</code></em>,
  44                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>);
  45 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-for-buffer" title="gst_type_find_helper_for_buffer ()">gst_type_find_helper_for_buffer</a>     (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
  46                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> *buf</code></em>,
  47                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);
  48 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-for-extension" title="gst_type_find_helper_for_extension ()">gst_type_find_helper_for_extension</a>  (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
  49                                                          <em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>);
  50 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a>       (<a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()">*GstTypeFindHelperGetRangeFunction</a>)
  51                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
  52                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> offset</code></em>,
  53                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> length</code></em>,
  54                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> **buffer</code></em>);
  55 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-get-range" title="gst_type_find_helper_get_range ()">gst_type_find_helper_get_range</a>      (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
  56                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> func</code></em>,
  57                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>,
  58                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);
  59 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-get-range-ext" title="gst_type_find_helper_get_range_ext ()">gst_type_find_helper_get_range_ext</a>  (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
  60                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> func</code></em>,
  61                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>,
  62                                                          <em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>,
  63                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);
  64 </pre>
  65 </div>
  66 <div class="refsect1">
  67 <a name="gstreamer-libs-GstTypeFindHelper.description"></a><h2>Description</h2>
  68 <p>
  69 Utility functions for elements doing typefinding:
  70 <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper" title="gst_type_find_helper ()"><code class="function">gst_type_find_helper()</code></a> does typefinding in pull mode, while
  71 <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-for-buffer" title="gst_type_find_helper_for_buffer ()"><code class="function">gst_type_find_helper_for_buffer()</code></a> is useful for elements needing to do
  72 typefinding in push mode from a chain function.
  73 </p>
  74 </div>
  75 <div class="refsect1">
  76 <a name="gstreamer-libs-GstTypeFindHelper.details"></a><h2>Details</h2>
  77 <div class="refsect2">
  78 <a name="gst-type-find-helper"></a><h3>gst_type_find_helper ()</h3>
  79 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           gst_type_find_helper                (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a> *src</code></em>,
  80                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>);</pre>
  81 <p>
  82 Tries to find what type of data is flowing from the given source <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a>.
  83 </p>
  84 <p>
  85 Free-function: gst_caps_unref
  86 </p>
  87 <div class="variablelist"><table border="0">
  88 <col align="left" valign="top">
  89 <tbody>
  90 <tr>
  91 <td><p><span class="term"><em class="parameter"><code>src</code></em> :</span></p></td>
  92 <td>A source <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a>
  93 </td>
  94 </tr>
  95 <tr>
  96 <td><p><span class="term"><em class="parameter"><code>size</code></em> :</span></p></td>
  97 <td>The length in bytes</td>
  98 </tr>
  99 <tr>
 100 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 101 <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> corresponding to the data stream.
 102 Returns <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a> if no <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> matches the data stream. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 103 </td>
 104 </tr>
 105 </tbody>
 106 </table></div>
 107 </div>
 108 <hr>
 109 <div class="refsect2">
 110 <a name="gst-type-find-helper-for-buffer"></a><h3>gst_type_find_helper_for_buffer ()</h3>
 111 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           gst_type_find_helper_for_buffer     (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
 112                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> *buf</code></em>,
 113                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre>
 114 <p>
 115 Tries to find what type of data is contained in the given <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a>, the
 116 assumption being that the buffer represents the beginning of the stream or
 117 file.
 118 </p>
 119 <p>
 120 All available typefinders will be called on the data in order of rank. If
 121 a typefinding function returns a probability of <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GST-TYPE-FIND-MAXIMUM:CAPS"><span class="type">GST_TYPE_FIND_MAXIMUM</span></a>,
 122 typefinding is stopped immediately and the found caps will be returned
 123 right away. Otherwise, all available typefind functions will the tried,
 124 and the caps with the highest probability will be returned, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a> if
 125 the content of the buffer could not be identified.
 126 </p>
 127 <p>
 128 Free-function: gst_caps_unref
 129 </p>
 130 <div class="variablelist"><table border="0">
 131 <col align="left" valign="top">
 132 <tbody>
 133 <tr>
 134 <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td>
 135 <td>object doing the typefinding, or NULL (used for logging)</td>
 136 </tr>
 137 <tr>
 138 <td><p><span class="term"><em class="parameter"><code>buf</code></em> :</span></p></td>
 139 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> with data to typefind. <span class="annotation">[<acronym title="Parameter for input. Default is transfer none."><span class="acronym">in</span></acronym>][<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span>
 140 </td>
 141 </tr>
 142 <tr>
 143 <td><p><span class="term"><em class="parameter"><code>prob</code></em> :</span></p></td>
 144 <td>location to store the probability of the found
 145 caps, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a>. <span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>][<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
 146 </td>
 147 </tr>
 148 <tr>
 149 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 150 <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> corresponding to the data, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a>
 151 if no type could be found. The caller should free the caps returned
 152 with <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a>. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 153 </td>
 154 </tr>
 155 </tbody>
 156 </table></div>
 157 </div>
 158 <hr>
 159 <div class="refsect2">
 160 <a name="gst-type-find-helper-for-extension"></a><h3>gst_type_find_helper_for_extension ()</h3>
 161 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           gst_type_find_helper_for_extension  (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
 162                                                          <em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>);</pre>
 163 <p>
 164 Tries to find the best <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> associated with <em class="parameter"><code>extension</code></em>.
 165 </p>
 166 <p>
 167 All available typefinders will be checked against the extension in order
 168 of rank. The caps of the first typefinder that can handle <em class="parameter"><code>extension</code></em> will be
 169 returned.
 170 </p>
 171 <p>
 172 Free-function: gst_caps_unref
 173 </p>
 174 <div class="variablelist"><table border="0">
 175 <col align="left" valign="top">
 176 <tbody>
 177 <tr>
 178 <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td>
 179 <td>object doing the typefinding, or NULL (used for logging). <span class="annotation">[<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
 180 </td>
 181 </tr>
 182 <tr>
 183 <td><p><span class="term"><em class="parameter"><code>extension</code></em> :</span></p></td>
 184 <td>an extension</td>
 185 </tr>
 186 <tr>
 187 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 188 <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> corresponding to <em class="parameter"><code>extension</code></em>, or
 189 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a> if no type could be found. The caller should free the caps
 190 returned with <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a>. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 191 </td>
 192 </tr>
 193 </tbody>
 194 </table></div>
 195 <p class="since">Since 0.10.23</p>
 196 </div>
 197 <hr>
 198 <div class="refsect2">
 199 <a name="GstTypeFindHelperGetRangeFunction"></a><h3>GstTypeFindHelperGetRangeFunction ()</h3>
 200 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a>       (*GstTypeFindHelperGetRangeFunction)
 201                                                         (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
 202                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> offset</code></em>,
 203                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> length</code></em>,
 204                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> **buffer</code></em>);</pre>
 205 <p>
 206 This function will be called by <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-get-range" title="gst_type_find_helper_get_range ()"><code class="function">gst_type_find_helper_get_range()</code></a> when
 207 typefinding functions request to peek at the data of a stream at certain
 208 offsets. If this function returns GST_FLOW_OK, the result buffer will be
 209 stored in <em class="parameter"><code>buffer</code></em>. The  contents of <em class="parameter"><code>buffer</code></em> is invalid for any other
 210 return value.
 211 </p>
 212 <p>
 213 This function is supposed to behave exactly like a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstPadGetRangeFunction"><span class="type">GstPadGetRangeFunction</span></a>.
 214 </p>
 215 <div class="variablelist"><table border="0">
 216 <col align="left" valign="top">
 217 <tbody>
 218 <tr>
 219 <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td>
 220 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> that will handle the getrange request</td>
 221 </tr>
 222 <tr>
 223 <td><p><span class="term"><em class="parameter"><code>offset</code></em> :</span></p></td>
 224 <td>the offset of the range</td>
 225 </tr>
 226 <tr>
 227 <td><p><span class="term"><em class="parameter"><code>length</code></em> :</span></p></td>
 228 <td>the length of the range</td>
 229 </tr>
 230 <tr>
 231 <td><p><span class="term"><em class="parameter"><code>buffer</code></em> :</span></p></td>
 232 <td>a memory location to hold the result buffer</td>
 233 </tr>
 234 <tr>
 235 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 236 <td>GST_FLOW_OK for success</td>
 237 </tr>
 238 </tbody>
 239 </table></div>
 240 </div>
 241 <hr>
 242 <div class="refsect2">
 243 <a name="gst-type-find-helper-get-range"></a><h3>gst_type_find_helper_get_range ()</h3>
 244 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           gst_type_find_helper_get_range      (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
 245                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> func</code></em>,
 246                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>,
 247                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre>
 248 <p>
 249 Utility function to do pull-based typefinding. Unlike <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper" title="gst_type_find_helper ()"><code class="function">gst_type_find_helper()</code></a>
 250 however, this function will use the specified function <em class="parameter"><code>func</code></em> to obtain the
 251 data needed by the typefind functions, rather than operating on a given
 252 source pad. This is useful mostly for elements like tag demuxers which
 253 strip off data at the beginning and/or end of a file and want to typefind
 254 the stripped data stream before adding their own source pad (the specified
 255 callback can then call the upstream peer pad with offsets adjusted for the
 256 tag size, for example).
 257 </p>
 258 <p>
 259 Free-function: gst_caps_unref
 260 </p>
 261 <div class="variablelist"><table border="0">
 262 <col align="left" valign="top">
 263 <tbody>
 264 <tr>
 265 <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td>
 266 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> that will be passed as first argument to <em class="parameter"><code>func</code></em>
 267 </td>
 268 </tr>
 269 <tr>
 270 <td><p><span class="term"><em class="parameter"><code>func</code></em> :</span></p></td>
 271 <td>A generic <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> that will
 272 be used to access data at random offsets when doing the typefinding. <span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span>
 273 </td>
 274 </tr>
 275 <tr>
 276 <td><p><span class="term"><em class="parameter"><code>size</code></em> :</span></p></td>
 277 <td>The length in bytes</td>
 278 </tr>
 279 <tr>
 280 <td><p><span class="term"><em class="parameter"><code>prob</code></em> :</span></p></td>
 281 <td>location to store the probability of the found
 282 caps, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a>. <span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>][<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
 283 </td>
 284 </tr>
 285 <tr>
 286 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 287 <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> corresponding to the data stream.
 288 Returns <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a> if no <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> matches the data stream. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 289 </td>
 290 </tr>
 291 </tbody>
 292 </table></div>
 293 </div>
 294 <hr>
 295 <div class="refsect2">
 296 <a name="gst-type-find-helper-get-range-ext"></a><h3>gst_type_find_helper_get_range_ext ()</h3>
 297 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> *           gst_type_find_helper_get_range_ext  (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> *obj</code></em>,
 298                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> func</code></em>,
 299                                                          <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>,
 300                                                          <em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>,
 301                                                          <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre>
 302 <p>
 303 Utility function to do pull-based typefinding. Unlike <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper" title="gst_type_find_helper ()"><code class="function">gst_type_find_helper()</code></a>
 304 however, this function will use the specified function <em class="parameter"><code>func</code></em> to obtain the
 305 data needed by the typefind functions, rather than operating on a given
 306 source pad. This is useful mostly for elements like tag demuxers which
 307 strip off data at the beginning and/or end of a file and want to typefind
 308 the stripped data stream before adding their own source pad (the specified
 309 callback can then call the upstream peer pad with offsets adjusted for the
 310 tag size, for example).
 311 </p>
 312 <p>
 313 When <em class="parameter"><code>extension</code></em> is not NULL, this function will first try the typefind
 314 functions for the given extension, which might speed up the typefinding
 315 in many cases.
 316 </p>
 317 <p>
 318 Free-function: gst_caps_unref
 319 </p>
 320 <div class="variablelist"><table border="0">
 321 <col align="left" valign="top">
 322 <tbody>
 323 <tr>
 324 <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td>
 325 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html"><span class="type">GstObject</span></a> that will be passed as first argument to <em class="parameter"><code>func</code></em>
 326 </td>
 327 </tr>
 328 <tr>
 329 <td><p><span class="term"><em class="parameter"><code>func</code></em> :</span></p></td>
 330 <td>A generic <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> that will
 331 be used to access data at random offsets when doing the typefinding. <span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span>
 332 </td>
 333 </tr>
 334 <tr>
 335 <td><p><span class="term"><em class="parameter"><code>size</code></em> :</span></p></td>
 336 <td>The length in bytes</td>
 337 </tr>
 338 <tr>
 339 <td><p><span class="term"><em class="parameter"><code>extension</code></em> :</span></p></td>
 340 <td>extension of the media</td>
 341 </tr>
 342 <tr>
 343 <td><p><span class="term"><em class="parameter"><code>prob</code></em> :</span></p></td>
 344 <td>location to store the probability of the found
 345 caps, or <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a>. <span class="annotation">[<acronym title="Parameter for returning results. Default is transfer full."><span class="acronym">out</span></acronym>][<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
 346 </td>
 347 </tr>
 348 <tr>
 349 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 350 <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> corresponding to the data stream.
 351 Returns <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><span class="type">NULL</span></a> if no <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> matches the data stream. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span>
 352 </td>
 353 </tr>
 354 </tbody>
 355 </table></div>
 356 <p class="since">Since 0.10.26</p>
 357 </div>
 358 </div>
 359 </div>
 360 <div class="footer">
 361 <hr>
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