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| <a name="gstreamer-libs-GstTypeFindHelper"></a><div class="titlepage"></div> |
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| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="gstreamer-libs-GstTypeFindHelper.top_of_page"></a>GstTypeFindHelper</span></h2> |
| <p>GstTypeFindHelper — Utility functions for typefinding</p> |
| </td> |
| <td class="gallery_image" valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1"> |
| <a name="gstreamer-libs-GstTypeFindHelper.functions"></a><h2>Functions</h2> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="functions_return"> |
| <col class="functions_name"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| </td> |
| <td class="function_name"> |
| <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper" title="gst_type_find_helper ()">gst_type_find_helper</a> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| </td> |
| <td class="function_name"> |
| <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> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| </td> |
| <td class="function_name"> |
| <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> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| </td> |
| <td class="function_name"> |
| <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#gst-type-find-helper-for-data" title="gst_type_find_helper_for_data ()">gst_type_find_helper_for_data</a> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a> |
| </td> |
| <td class="function_name"> |
| <span class="c_punctuation">(</span><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()">*GstTypeFindHelperGetRangeFunction</a><span class="c_punctuation">)</span> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| </td> |
| <td class="function_name"> |
| <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> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect1"> |
| <a name="gstreamer-libs-GstTypeFindHelper.includes"></a><h2>Includes</h2> |
| <pre class="synopsis">#include <gst/base/gsttypefindhelper.h> |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="gstreamer-libs-GstTypeFindHelper.description"></a><h2>Description</h2> |
| <p>Utility functions for elements doing typefinding: |
| <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 |
| <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 |
| typefinding in push mode from a chain function.</p> |
| </div> |
| <div class="refsect1"> |
| <a name="gstreamer-libs-GstTypeFindHelper.functions_details"></a><h2>Functions</h2> |
| <div class="refsect2"> |
| <a name="gst-type-find-helper"></a><h3>gst_type_find_helper ()</h3> |
| <pre class="programlisting"><a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| gst_type_find_helper (<em class="parameter"><code><a href="../html/GstPad.html#GstPad-struct"><span class="type">GstPad</span></a> *src</code></em>, |
| <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>);</pre> |
| <p>Tries to find what type of data is flowing from the given source <a href="../html/GstPad.html#GstPad-struct"><span class="type">GstPad</span></a>.</p> |
| <p>Free-function: gst_caps_unref</p> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>src</p></td> |
| <td class="parameter_description"><p>A source <a href="../html/GstPad.html#GstPad-struct"><span class="type">GstPad</span></a></p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>size</p></td> |
| <td class="parameter_description"><p>The length in bytes</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper.returns"></a><h4>Returns</h4> |
| <p> the <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> corresponding to the data |
| stream. Returns <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if no <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> matches the data stream. </p> |
| <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<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> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-type-find-helper-for-buffer"></a><h3>gst_type_find_helper_for_buffer ()</h3> |
| <pre class="programlisting"><a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| gst_type_find_helper_for_buffer (<em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *obj</code></em>, |
| <em class="parameter"><code><a href="../html/GstBuffer.html#GstBuffer-struct"><span class="type">GstBuffer</span></a> *buf</code></em>, |
| <em class="parameter"><code><a href="../html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre> |
| <p>Tries to find what type of data is contained in the given <a href="../html/GstBuffer.html#GstBuffer-struct"><span class="type">GstBuffer</span></a>, the |
| assumption being that the buffer represents the beginning of the stream or |
| file.</p> |
| <p>All available typefinders will be called on the data in order of rank. If |
| a typefinding function returns a probability of <a href="../html/gstreamer-GstTypeFind.html#GST-TYPE-FIND-MAXIMUM:CAPS"><code class="literal">GST_TYPE_FIND_MAXIMUM</code></a>, |
| typefinding is stopped immediately and the found caps will be returned |
| right away. Otherwise, all available typefind functions will the tried, |
| and the caps with the highest probability will be returned, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if |
| the content of the buffer could not be identified.</p> |
| <p>Free-function: gst_caps_unref</p> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-buffer.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>obj</p></td> |
| <td class="parameter_description"><p> object doing the typefinding, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> (used for logging). </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>buf</p></td> |
| <td class="parameter_description"><p> a <a href="../html/GstBuffer.html#GstBuffer-struct"><span class="type">GstBuffer</span></a> with data to typefind. </p></td> |
| <td class="parameter_annotations"><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></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>prob</p></td> |
| <td class="parameter_description"><p> location to store the probability of the found |
| caps, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. </p></td> |
| <td class="parameter_annotations"><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></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-buffer.returns"></a><h4>Returns</h4> |
| <p> the <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> corresponding to the data, |
| or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if no type could be found. The caller should free the caps |
| returned with <a href="../html/GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a>. </p> |
| <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<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> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-type-find-helper-for-extension"></a><h3>gst_type_find_helper_for_extension ()</h3> |
| <pre class="programlisting"><a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| gst_type_find_helper_for_extension (<em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *obj</code></em>, |
| <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>);</pre> |
| <p>Tries to find the best <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> associated with <em class="parameter"><code>extension</code></em> |
| .</p> |
| <p>All available typefinders will be checked against the extension in order |
| of rank. The caps of the first typefinder that can handle <em class="parameter"><code>extension</code></em> |
| will be |
| returned.</p> |
| <p>Free-function: gst_caps_unref</p> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-extension.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>obj</p></td> |
| <td class="parameter_description"><p> object doing the typefinding, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> (used for logging). </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>extension</p></td> |
| <td class="parameter_description"><p>an extension</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-extension.returns"></a><h4>Returns</h4> |
| <p> the <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> corresponding to |
| <em class="parameter"><code>extension</code></em> |
| , or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if no type could be found. The caller should free |
| the caps returned with <a href="../html/GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a>. </p> |
| <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<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> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-type-find-helper-for-data"></a><h3>gst_type_find_helper_for_data ()</h3> |
| <pre class="programlisting"><a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| gst_type_find_helper_for_data (<em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *obj</code></em>, |
| <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint8"><span class="type">guint8</span></a> *data</code></em>, |
| <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gsize"><span class="type">gsize</span></a> size</code></em>, |
| <em class="parameter"><code><a href="../html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre> |
| <p>Tries to find what type of data is contained in the given <em class="parameter"><code>data</code></em> |
| , the |
| assumption being that the data represents the beginning of the stream or |
| file.</p> |
| <p>All available typefinders will be called on the data in order of rank. If |
| a typefinding function returns a probability of <a href="../html/gstreamer-GstTypeFind.html#GST-TYPE-FIND-MAXIMUM:CAPS"><code class="literal">GST_TYPE_FIND_MAXIMUM</code></a>, |
| typefinding is stopped immediately and the found caps will be returned |
| right away. Otherwise, all available typefind functions will the tried, |
| and the caps with the highest probability will be returned, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if |
| the content of <em class="parameter"><code>data</code></em> |
| could not be identified.</p> |
| <p>Free-function: gst_caps_unref</p> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-data.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>obj</p></td> |
| <td class="parameter_description"><p> object doing the typefinding, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> (used for logging). </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>data</p></td> |
| <td class="parameter_description"><p> a pointer with data to typefind. </p></td> |
| <td class="parameter_annotations"><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></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>size</p></td> |
| <td class="parameter_description"><p> the size of <em class="parameter"><code>data</code></em> |
| . </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="Parameter for input. Default is transfer none."><span class="acronym">in</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>prob</p></td> |
| <td class="parameter_description"><p> location to store the probability of the found |
| caps, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. </p></td> |
| <td class="parameter_annotations"><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></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-for-data.returns"></a><h4>Returns</h4> |
| <p> the <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> corresponding to the data, |
| or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if no type could be found. The caller should free the caps |
| returned with <a href="../html/GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a>. </p> |
| <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<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> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstTypeFindHelperGetRangeFunction"></a><h3>GstTypeFindHelperGetRangeFunction ()</h3> |
| <pre class="programlisting"><a href="../html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a> |
| <span class="c_punctuation">(</span>*GstTypeFindHelperGetRangeFunction<span class="c_punctuation">)</span> (<em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *obj</code></em>, |
| <em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *parent</code></em>, |
| <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint64"><span class="type">guint64</span></a> offset</code></em>, |
| <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint"><span class="type">guint</span></a> length</code></em>, |
| <em class="parameter"><code><a href="../html/GstBuffer.html#GstBuffer-struct"><span class="type">GstBuffer</span></a> **buffer</code></em>);</pre> |
| <p>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 |
| typefinding functions request to peek at the data of a stream at certain |
| offsets. If this function returns GST_FLOW_OK, the result buffer will be |
| stored in <em class="parameter"><code>buffer</code></em> |
| . The contents of <em class="parameter"><code>buffer</code></em> |
| is invalid for any other |
| return value.</p> |
| <p>This function is supposed to behave exactly like a <a href="../html/GstPad.html#GstPadGetRangeFunction"><span class="type">GstPadGetRangeFunction</span></a>.</p> |
| <div class="refsect3"> |
| <a name="GstTypeFindHelperGetRangeFunction.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>obj</p></td> |
| <td class="parameter_description"><p>a <a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> that will handle the getrange request</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>parent</p></td> |
| <td class="parameter_description"><p> the parent of <em class="parameter"><code>obj</code></em> |
| or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>offset</p></td> |
| <td class="parameter_description"><p>the offset of the range</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>length</p></td> |
| <td class="parameter_description"><p>the length of the range</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>buffer</p></td> |
| <td class="parameter_description"><p>a memory location to hold the result buffer</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="GstTypeFindHelperGetRangeFunction.returns"></a><h4>Returns</h4> |
| <p> GST_FLOW_OK for success</p> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-type-find-helper-get-range"></a><h3>gst_type_find_helper_get_range ()</h3> |
| <pre class="programlisting"><a href="../html/GstCaps.html#GstCaps-struct"><span class="returnvalue">GstCaps</span></a> * |
| gst_type_find_helper_get_range (<em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *obj</code></em>, |
| <em class="parameter"><code><a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> *parent</code></em>, |
| <em class="parameter"><code><a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> func</code></em>, |
| <em class="parameter"><code><a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#guint64"><span class="type">guint64</span></a> size</code></em>, |
| <em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/glibglib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *extension</code></em>, |
| <em class="parameter"><code><a href="../html/gstreamer-GstTypeFind.html#GstTypeFindProbability"><span class="type">GstTypeFindProbability</span></a> *prob</code></em>);</pre> |
| <p>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> |
| however, this function will use the specified function <em class="parameter"><code>func</code></em> |
| to obtain the |
| data needed by the typefind functions, rather than operating on a given |
| source pad. This is useful mostly for elements like tag demuxers which |
| strip off data at the beginning and/or end of a file and want to typefind |
| the stripped data stream before adding their own source pad (the specified |
| callback can then call the upstream peer pad with offsets adjusted for the |
| tag size, for example).</p> |
| <p>When <em class="parameter"><code>extension</code></em> |
| is not <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, this function will first try the typefind |
| functions for the given extension, which might speed up the typefinding |
| in many cases.</p> |
| <p>Free-function: gst_caps_unref</p> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-get-range.parameters"></a><h4>Parameters</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="parameters_name"> |
| <col class="parameters_description"> |
| <col width="200px" class="parameters_annotations"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="parameter_name"><p>obj</p></td> |
| <td class="parameter_description"><p>A <a href="../html/GstObject.html#GstObject-struct"><span class="type">GstObject</span></a> that will be passed as first argument to <em class="parameter"><code>func</code></em> |
| </p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>parent</p></td> |
| <td class="parameter_description"><p> the parent of <em class="parameter"><code>obj</code></em> |
| or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="NULL is OK, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>func</p></td> |
| <td class="parameter_description"><p> A generic <a class="link" href="gstreamer-libs-GstTypeFindHelper.html#GstTypeFindHelperGetRangeFunction" title="GstTypeFindHelperGetRangeFunction ()"><span class="type">GstTypeFindHelperGetRangeFunction</span></a> that will |
| be used to access data at random offsets when doing the typefinding. </p></td> |
| <td class="parameter_annotations"><span class="annotation">[<acronym title="The callback is valid only during the call to the method."><span class="acronym">scope call</span></acronym>]</span></td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>size</p></td> |
| <td class="parameter_description"><p>The length in bytes</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>extension</p></td> |
| <td class="parameter_description"><p>extension of the media</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>prob</p></td> |
| <td class="parameter_description"><p> location to store the probability of the found |
| caps, or <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. </p></td> |
| <td class="parameter_annotations"><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></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect3"> |
| <a name="gst-type-find-helper-get-range.returns"></a><h4>Returns</h4> |
| <p> the <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> corresponding to the data |
| stream. Returns <a href="/usr/share/gtk-doc/html/glibglib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> if no <a href="../html/GstCaps.html#GstCaps-struct"><span class="type">GstCaps</span></a> matches the data stream. </p> |
| <p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>][<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> |
| </div> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gstreamer-libs-GstTypeFindHelper.other_details"></a><h2>Types and Values</h2> |
| </div> |
| </div> |
| <div class="footer"> |
| <hr>Generated by GTK-Doc V1.25</div> |
| </body> |
| </html> |
