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  33 <h2><span class="refentrytitle"><a name="gstreamer-libs-gstdataprotocol.top_of_page"></a>gstdataprotocol</span></h2>
  34 <p>gstdataprotocol — Serialization of caps, buffers and events.</p>
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  39 <a name="gstreamer-libs-gstdataprotocol.synopsis"></a><h2>Synopsis</h2>
  40 <pre class="synopsis">
  41 #include &lt;gst/dataprotocol/dataprotocol.h&gt;
  42
  43 enum                <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag">GstDPHeaderFlag</a>;
  44 enum                <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPayloadType" title="enum GstDPPayloadType">GstDPPayloadType</a>;
  45 #define             <a class="link" href="gstreamer-libs-gstdataprotocol.html#GST-DP-HEADER-LENGTH:CAPS" title="GST_DP_HEADER_LENGTH">GST_DP_HEADER_LENGTH</a>
  46 enum                <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion">GstDPVersion</a>;
  47 #define             <a class="link" href="gstreamer-libs-gstdataprotocol.html#GST-DP-VERSION-MAJOR:CAPS" title="GST_DP_VERSION_MAJOR">GST_DP_VERSION_MAJOR</a>
  48 #define             <a class="link" href="gstreamer-libs-gstdataprotocol.html#GST-DP-VERSION-MINOR:CAPS" title="GST_DP_VERSION_MINOR">GST_DP_VERSION_MINOR</a>
  49 <span class="returnvalue">void</span>                <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-init" title="gst_dp_init ()">gst_dp_init</a>                         (<em class="parameter"><code><span class="type">void</span></code></em>);
  50 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (<a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFromBufferFunction" title="GstDPHeaderFromBufferFunction ()">*GstDPHeaderFromBufferFunction</a>)    (<em class="parameter"><code>const <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>,
  51                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  52                                                          <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>,
  53                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>);
  54 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (<a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketFromCapsFunction" title="GstDPPacketFromCapsFunction ()">*GstDPPacketFromCapsFunction</a>)      (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
  55                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  56                                                          <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>,
  57                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
  58                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);
  59 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (<a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketFromEventFunction" title="GstDPPacketFromEventFunction ()">*GstDPPacketFromEventFunction</a>)     (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> *event</code></em>,
  60                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  61                                                          <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>,
  62                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
  63                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);
  64                     <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer">GstDPPacketizer</a>;
  65 <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="returnvalue">GstDPPacketizer</span></a> *   <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-packetizer-new" title="gst_dp_packetizer_new ()">gst_dp_packetizer_new</a>               (<em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion"><span class="type">GstDPVersion</span></a> version</code></em>);
  66 <span class="returnvalue">void</span>                <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-packetizer-free" title="gst_dp_packetizer_free ()">gst_dp_packetizer_free</a>              (<em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a> *packetizer</code></em>);
  67 <span class="returnvalue">guint16</span>             <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-crc" title="gst_dp_crc ()">gst_dp_crc</a>                          (<em class="parameter"><code>const <span class="type">guint8</span> *buffer</code></em>,
  68                                                          <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>);
  69 <span class="returnvalue">guint32</span>             <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-header-payload-length" title="gst_dp_header_payload_length ()">gst_dp_header_payload_length</a>        (<em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);
  70 <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPayloadType" title="enum GstDPPayloadType"><span class="returnvalue">GstDPPayloadType</span></a>    <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-header-payload-type" title="gst_dp_header_payload_type ()">gst_dp_header_payload_type</a>          (<em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);
  71 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-header-from-buffer" title="gst_dp_header_from_buffer ()">gst_dp_header_from_buffer</a>           (<em class="parameter"><code>const <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>,
  72                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  73                                                          <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>,
  74                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>);
  75 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-packet-from-caps" title="gst_dp_packet_from_caps ()">gst_dp_packet_from_caps</a>             (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
  76                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  77                                                          <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>,
  78                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
  79                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);
  80 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-packet-from-event" title="gst_dp_packet_from_event ()">gst_dp_packet_from_event</a>            (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> *event</code></em>,
  81                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
  82                                                          <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>,
  83                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
  84                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);
  85 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="returnvalue">GstBuffer</span></a> *         <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-buffer-from-header" title="gst_dp_buffer_from_header ()">gst_dp_buffer_from_header</a>           (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  86                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);
  87 <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-gstdataprotocol.html#gst-dp-caps-from-packet" title="gst_dp_caps_from_packet ()">gst_dp_caps_from_packet</a>             (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  88                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
  89                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);
  90 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="returnvalue">GstEvent</span></a> *          <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-event-from-packet" title="gst_dp_event_from_packet ()">gst_dp_event_from_packet</a>            (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  91                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
  92                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);
  93 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-header" title="gst_dp_validate_header ()">gst_dp_validate_header</a>              (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  94                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);
  95 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-payload" title="gst_dp_validate_payload ()">gst_dp_validate_payload</a>             (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  96                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
  97                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);
  98 <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-packet" title="gst_dp_validate_packet ()">gst_dp_validate_packet</a>              (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
  99                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
 100                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);
 101 </pre>
 102 </div>
 103 <div class="refsect1">
 104 <a name="gstreamer-libs-gstdataprotocol.description"></a><h2>Description</h2>
 105 <p>
 106 This helper library provides serialization of GstBuffer, GstCaps and
 107 GstEvent structures.
 108 </p>
 109 <p>
 110 This serialization is useful when GStreamer needs to interface with
 111 the outside world to transport data between distinct GStreamer pipelines.
 112 The connections with the outside world generally don't have mechanisms
 113 to transport properties of these structures.
 114 </p>
 115 <p>
 116 For example, transporting buffers across named pipes or network connections
 117 doesn't maintain the buffer size and separation.
 118 </p>
 119 <p>
 120 This data protocol assumes a reliable connection-oriented transport, such as
 121 TCP, a pipe, or a file.  The protocol does not serialize the caps for
 122 each buffer; instead, it transport the caps only when they change in the
 123 stream.  This implies that there will always be a caps packet before any
 124 buffer packets.
 125 </p>
 126 <p>
 127 The versioning of the protocol is independent of GStreamer's version.
 128 The major number gets incremented, and the minor reset, for incompatible
 129 changes.  The minor number gets incremented for compatible changes that
 130 allow clients who do not completely understand the newer protocol version
 131 to still decode what they do understand.
 132 </p>
 133 <p>
 134 Version 0.2 serializes only a small subset of all events, with a custom
 135 payload for each type.  Also, all GDP streams start with the initial caps
 136 packet.
 137 </p>
 138 <p>
 139 Version 1.0 serializes all events by taking the string representation of
 140 the event as the payload.  In addition, GDP streams can now start with
 141 events as well, as required by the new data stream model in GStreamer 0.10.
 142 </p>
 143 <p>
 144 Converting buffers, caps and events to GDP buffers is done using a
 145 <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a> object and invoking its packetizer functions.
 146 For backwards-compatibility reasons, the old 0.2 methods are still
 147 available but deprecated.
 148 </p>
 149 <p>
 150 For reference, this image shows the byte layout of the GDP header:
 151 </p>
 152 <p>
 153 <img src="gdp-header.png">
 154 </p>
 155 </div>
 156 <div class="refsect1">
 157 <a name="gstreamer-libs-gstdataprotocol.details"></a><h2>Details</h2>
 158 <div class="refsect2">
 159 <a name="GstDPHeaderFlag"></a><h3>enum GstDPHeaderFlag</h3>
 160 <pre class="programlisting">typedef enum {
 161   GST_DP_HEADER_FLAG_NONE        = 0,
 162   GST_DP_HEADER_FLAG_CRC_HEADER  = (1 &lt;&lt; 0),
 163   GST_DP_HEADER_FLAG_CRC_PAYLOAD = (1 &lt;&lt; 1),
 164   GST_DP_HEADER_FLAG_CRC         = (1 &lt;&lt; 1) | (1 &lt;&lt; 0),
 165 } GstDPHeaderFlag;
 166 </pre>
 167 <p>
 168 header flags for the dataprotocol.
 169 </p>
 170 <div class="variablelist"><table border="0">
 171 <col align="left" valign="top">
 172 <tbody>
 173 <tr>
 174 <td><p><a name="GST-DP-HEADER-FLAG-NONE:CAPS"></a><span class="term"><code class="literal">GST_DP_HEADER_FLAG_NONE</code></span></p></td>
 175 <td>No flag present.
 176 </td>
 177 </tr>
 178 <tr>
 179 <td><p><a name="GST-DP-HEADER-FLAG-CRC-HEADER:CAPS"></a><span class="term"><code class="literal">GST_DP_HEADER_FLAG_CRC_HEADER</code></span></p></td>
 180 <td>a header CRC field is present.
 181 </td>
 182 </tr>
 183 <tr>
 184 <td><p><a name="GST-DP-HEADER-FLAG-CRC-PAYLOAD:CAPS"></a><span class="term"><code class="literal">GST_DP_HEADER_FLAG_CRC_PAYLOAD</code></span></p></td>
 185 <td>a payload CRC field is present.
 186 </td>
 187 </tr>
 188 <tr>
 189 <td><p><a name="GST-DP-HEADER-FLAG-CRC:CAPS"></a><span class="term"><code class="literal">GST_DP_HEADER_FLAG_CRC</code></span></p></td>
 190 <td>a CRC for header and payload is present.
 191 </td>
 192 </tr>
 193 </tbody>
 194 </table></div>
 195 </div>
 196 <hr>
 197 <div class="refsect2">
 198 <a name="GstDPPayloadType"></a><h3>enum GstDPPayloadType</h3>
 199 <pre class="programlisting">typedef enum {
 200   GST_DP_PAYLOAD_NONE            = 0,
 201   GST_DP_PAYLOAD_BUFFER,
 202   GST_DP_PAYLOAD_CAPS,
 203   GST_DP_PAYLOAD_EVENT_NONE      = 64,
 204 } GstDPPayloadType;
 205 </pre>
 206 <p>
 207 The GDP payload types. a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> payload type is encoded with the
 208 event type number starting from <em class="parameter"><code>GST_DP_PAYLOAD_EVENT_NONE</code></em>.
 209 </p>
 210 <div class="variablelist"><table border="0">
 211 <col align="left" valign="top">
 212 <tbody>
 213 <tr>
 214 <td><p><a name="GST-DP-PAYLOAD-NONE:CAPS"></a><span class="term"><code class="literal">GST_DP_PAYLOAD_NONE</code></span></p></td>
 215 <td>Invalid payload type.
 216 </td>
 217 </tr>
 218 <tr>
 219 <td><p><a name="GST-DP-PAYLOAD-BUFFER:CAPS"></a><span class="term"><code class="literal">GST_DP_PAYLOAD_BUFFER</code></span></p></td>
 220 <td>
 221 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> payload packet.
 222 </td>
 223 </tr>
 224 <tr>
 225 <td><p><a name="GST-DP-PAYLOAD-CAPS"></a><span class="term"><code class="literal">GST_DP_PAYLOAD_CAPS</code></span></p></td>
 226 <td>
 227 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> payload packet.
 228 </td>
 229 </tr>
 230 <tr>
 231 <td><p><a name="GST-DP-PAYLOAD-EVENT-NONE:CAPS"></a><span class="term"><code class="literal">GST_DP_PAYLOAD_EVENT_NONE</code></span></p></td>
 232 <td>First value of <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> payload packets.
 233 </td>
 234 </tr>
 235 </tbody>
 236 </table></div>
 237 </div>
 238 <hr>
 239 <div class="refsect2">
 240 <a name="GST-DP-HEADER-LENGTH:CAPS"></a><h3>GST_DP_HEADER_LENGTH</h3>
 241 <pre class="programlisting">#define GST_DP_HEADER_LENGTH 62
 242 </pre>
 243 <p>
 244 The header size in bytes.
 245 </p>
 246 </div>
 247 <hr>
 248 <div class="refsect2">
 249 <a name="GstDPVersion"></a><h3>enum GstDPVersion</h3>
 250 <pre class="programlisting">typedef enum {
 251   GST_DP_VERSION_0_2 = 1,
 252   GST_DP_VERSION_1_0,
 253 } GstDPVersion;
 254 </pre>
 255 <p>
 256 The version of the GDP protocol being used.
 257 </p>
 258 <div class="variablelist"><table border="0">
 259 <col align="left" valign="top">
 260 <tbody>
 261 <tr>
 262 <td><p><a name="GST-DP-VERSION-0-2:CAPS"></a><span class="term"><code class="literal">GST_DP_VERSION_0_2</code></span></p></td>
 263 <td>protocol version 0.2
 264 </td>
 265 </tr>
 266 <tr>
 267 <td><p><a name="GST-DP-VERSION-1-0:CAPS"></a><span class="term"><code class="literal">GST_DP_VERSION_1_0</code></span></p></td>
 268 <td>protocol version 1.0
 269 </td>
 270 </tr>
 271 </tbody>
 272 </table></div>
 273 </div>
 274 <hr>
 275 <div class="refsect2">
 276 <a name="GST-DP-VERSION-MAJOR:CAPS"></a><h3>GST_DP_VERSION_MAJOR</h3>
 277 <pre class="programlisting">#define GST_DP_VERSION_MAJOR 0
 278 </pre>
 279 <p>
 280 The major version number of the GStreamer Data Protocol.
 281 </p>
 282 </div>
 283 <hr>
 284 <div class="refsect2">
 285 <a name="GST-DP-VERSION-MINOR:CAPS"></a><h3>GST_DP_VERSION_MINOR</h3>
 286 <pre class="programlisting">#define GST_DP_VERSION_MINOR 2
 287 </pre>
 288 <p>
 289 The minor version number of the GStreamer Data Protocol.
 290 </p>
 291 </div>
 292 <hr>
 293 <div class="refsect2">
 294 <a name="gst-dp-init"></a><h3>gst_dp_init ()</h3>
 295 <pre class="programlisting"><span class="returnvalue">void</span>                gst_dp_init                         (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
 296 <p>
 297 Initialize GStreamer Data Protocol library.
 298 </p>
 299 <p>
 300 Should be called before using these functions from source linking
 301 to this source file.
 302 </p>
 303 </div>
 304 <hr>
 305 <div class="refsect2">
 306 <a name="GstDPHeaderFromBufferFunction"></a><h3>GstDPHeaderFromBufferFunction ()</h3>
 307 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (*GstDPHeaderFromBufferFunction)    (<em class="parameter"><code>const <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>,
 308                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 309                                                          <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>,
 310                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>);</pre>
 311 </div>
 312 <hr>
 313 <div class="refsect2">
 314 <a name="GstDPPacketFromCapsFunction"></a><h3>GstDPPacketFromCapsFunction ()</h3>
 315 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (*GstDPPacketFromCapsFunction)      (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
 316                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 317                                                          <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>,
 318                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
 319                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);</pre>
 320 </div>
 321 <hr>
 322 <div class="refsect2">
 323 <a name="GstDPPacketFromEventFunction"></a><h3>GstDPPacketFromEventFunction ()</h3>
 324 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            (*GstDPPacketFromEventFunction)     (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> *event</code></em>,
 325                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 326                                                          <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>,
 327                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
 328                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);</pre>
 329 </div>
 330 <hr>
 331 <div class="refsect2">
 332 <a name="GstDPPacketizer"></a><h3>GstDPPacketizer</h3>
 333 <pre class="programlisting">typedef struct {
 334   GstDPVersion version;
 335
 336   GstDPHeaderFromBufferFunction header_from_buffer;
 337   GstDPPacketFromCapsFunction packet_from_caps;
 338   GstDPPacketFromEventFunction packet_from_event;
 339 } GstDPPacketizer;
 340 </pre>
 341 <p>
 342 Data protocol packetizer handle.
 343 </p>
 344 <div class="variablelist"><table border="0">
 345 <col align="left" valign="top">
 346 <tbody>
 347 <tr>
 348 <td><p><span class="term"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion"><span class="type">GstDPVersion</span></a> <em class="structfield"><code><a name="GstDPPacketizer.version"></a>version</code></em>;</span></p></td>
 349 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion"><span class="type">GstDPVersion</span></a> of the protocol to be used</td>
 350 </tr>
 351 <tr>
 352 <td><p><span class="term"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFromBufferFunction" title="GstDPHeaderFromBufferFunction ()"><span class="type">GstDPHeaderFromBufferFunction</span></a> <em class="structfield"><code><a name="GstDPPacketizer.header-from-buffer"></a>header_from_buffer</code></em>;</span></p></td>
 353 <td>buffer serializer function</td>
 354 </tr>
 355 <tr>
 356 <td><p><span class="term"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketFromCapsFunction" title="GstDPPacketFromCapsFunction ()"><span class="type">GstDPPacketFromCapsFunction</span></a> <em class="structfield"><code><a name="GstDPPacketizer.packet-from-caps"></a>packet_from_caps</code></em>;</span></p></td>
 357 <td>caps serializer function</td>
 358 </tr>
 359 <tr>
 360 <td><p><span class="term"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketFromEventFunction" title="GstDPPacketFromEventFunction ()"><span class="type">GstDPPacketFromEventFunction</span></a> <em class="structfield"><code><a name="GstDPPacketizer.packet-from-event"></a>packet_from_event</code></em>;</span></p></td>
 361 <td>event serializer function</td>
 362 </tr>
 363 </tbody>
 364 </table></div>
 365 </div>
 366 <hr>
 367 <div class="refsect2">
 368 <a name="gst-dp-packetizer-new"></a><h3>gst_dp_packetizer_new ()</h3>
 369 <pre class="programlisting"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="returnvalue">GstDPPacketizer</span></a> *   gst_dp_packetizer_new               (<em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion"><span class="type">GstDPVersion</span></a> version</code></em>);</pre>
 370 <p>
 371 Creates a new packetizer.
 372 </p>
 373 <div class="variablelist"><table border="0">
 374 <col align="left" valign="top">
 375 <tbody>
 376 <tr>
 377 <td><p><span class="term"><em class="parameter"><code>version</code></em> :</span></p></td>
 378 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPVersion" title="enum GstDPVersion"><span class="type">GstDPVersion</span></a> of the protocol to packetize for.</td>
 379 </tr>
 380 <tr>
 381 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 382 <td>a newly allocated <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a>
 383 </td>
 384 </tr>
 385 </tbody>
 386 </table></div>
 387 </div>
 388 <hr>
 389 <div class="refsect2">
 390 <a name="gst-dp-packetizer-free"></a><h3>gst_dp_packetizer_free ()</h3>
 391 <pre class="programlisting"><span class="returnvalue">void</span>                gst_dp_packetizer_free              (<em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a> *packetizer</code></em>);</pre>
 392 <p>
 393 Free the given packetizer.
 394 </p>
 395 <div class="variablelist"><table border="0">
 396 <col align="left" valign="top">
 397 <tbody><tr>
 398 <td><p><span class="term"><em class="parameter"><code>packetizer</code></em> :</span></p></td>
 399 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a> to free.</td>
 400 </tr></tbody>
 401 </table></div>
 402 </div>
 403 <hr>
 404 <div class="refsect2">
 405 <a name="gst-dp-crc"></a><h3>gst_dp_crc ()</h3>
 406 <pre class="programlisting"><span class="returnvalue">guint16</span>             gst_dp_crc                          (<em class="parameter"><code>const <span class="type">guint8</span> *buffer</code></em>,
 407                                                          <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>);</pre>
 408 <p>
 409 Calculate a CRC for the given buffer over the given number of bytes.
 410 This is only provided for verification purposes; typical GDP users
 411 will not need this function.
 412 </p>
 413 <div class="variablelist"><table border="0">
 414 <col align="left" valign="top">
 415 <tbody>
 416 <tr>
 417 <td><p><span class="term"><em class="parameter"><code>buffer</code></em> :</span></p></td>
 418 <td>array of bytes</td>
 419 </tr>
 420 <tr>
 421 <td><p><span class="term"><em class="parameter"><code>length</code></em> :</span></p></td>
 422 <td>the length of <em class="parameter"><code>buffer</code></em>
 423 </td>
 424 </tr>
 425 <tr>
 426 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 427 <td>a two-byte CRC checksum.</td>
 428 </tr>
 429 </tbody>
 430 </table></div>
 431 </div>
 432 <hr>
 433 <div class="refsect2">
 434 <a name="gst-dp-header-payload-length"></a><h3>gst_dp_header_payload_length ()</h3>
 435 <pre class="programlisting"><span class="returnvalue">guint32</span>             gst_dp_header_payload_length        (<em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);</pre>
 436 <p>
 437 Get the length of the payload described by <em class="parameter"><code>header</code></em>.
 438 </p>
 439 <div class="variablelist"><table border="0">
 440 <col align="left" valign="top">
 441 <tbody>
 442 <tr>
 443 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 444 <td>the byte header of the packet array</td>
 445 </tr>
 446 <tr>
 447 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 448 <td>the length of the payload this header describes.</td>
 449 </tr>
 450 </tbody>
 451 </table></div>
 452 </div>
 453 <hr>
 454 <div class="refsect2">
 455 <a name="gst-dp-header-payload-type"></a><h3>gst_dp_header_payload_type ()</h3>
 456 <pre class="programlisting"><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPayloadType" title="enum GstDPPayloadType"><span class="returnvalue">GstDPPayloadType</span></a>    gst_dp_header_payload_type          (<em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);</pre>
 457 <p>
 458 Get the type of the payload described by <em class="parameter"><code>header</code></em>.
 459 </p>
 460 <div class="variablelist"><table border="0">
 461 <col align="left" valign="top">
 462 <tbody>
 463 <tr>
 464 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 465 <td>the byte header of the packet array</td>
 466 </tr>
 467 <tr>
 468 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 469 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPayloadType" title="enum GstDPPayloadType"><span class="type">GstDPPayloadType</span></a> the payload this header describes.</td>
 470 </tr>
 471 </tbody>
 472 </table></div>
 473 </div>
 474 <hr>
 475 <div class="refsect2">
 476 <a name="gst-dp-header-from-buffer"></a><h3>gst_dp_header_from_buffer ()</h3>
 477 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_header_from_buffer           (<em class="parameter"><code>const <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>,
 478                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 479                                                          <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>,
 480                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>);</pre>
 481 <div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
 482 <h3 class="title">Warning</h3>
 483 <p><code class="literal">gst_dp_header_from_buffer</code> is deprecated and should not be used in newly-written code. use a <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a></p>
 484 </div>
 485 <p>
 486 Creates a GDP header from the given buffer.
 487 </p>
 488 <div class="variablelist"><table border="0">
 489 <col align="left" valign="top">
 490 <tbody>
 491 <tr>
 492 <td><p><span class="term"><em class="parameter"><code>buffer</code></em> :</span></p></td>
 493 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> to create a header for</td>
 494 </tr>
 495 <tr>
 496 <td><p><span class="term"><em class="parameter"><code>flags</code></em> :</span></p></td>
 497 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> to create the header with</td>
 498 </tr>
 499 <tr>
 500 <td><p><span class="term"><em class="parameter"><code>length</code></em> :</span></p></td>
 501 <td>a guint pointer to store the header length in</td>
 502 </tr>
 503 <tr>
 504 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 505 <td>a guint8 * pointer to store a newly allocated header byte array in</td>
 506 </tr>
 507 <tr>
 508 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 509 <td>
 510 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the header was successfully created.</td>
 511 </tr>
 512 </tbody>
 513 </table></div>
 514 </div>
 515 <hr>
 516 <div class="refsect2">
 517 <a name="gst-dp-packet-from-caps"></a><h3>gst_dp_packet_from_caps ()</h3>
 518 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_packet_from_caps             (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>,
 519                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 520                                                          <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>,
 521                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
 522                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);</pre>
 523 <div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
 524 <h3 class="title">Warning</h3>
 525 <p><code class="literal">gst_dp_packet_from_caps</code> is deprecated and should not be used in newly-written code. use a <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a></p>
 526 </div>
 527 <p>
 528 Creates a GDP packet from the given caps.
 529 </p>
 530 <div class="variablelist"><table border="0">
 531 <col align="left" valign="top">
 532 <tbody>
 533 <tr>
 534 <td><p><span class="term"><em class="parameter"><code>caps</code></em> :</span></p></td>
 535 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> to create a packet for</td>
 536 </tr>
 537 <tr>
 538 <td><p><span class="term"><em class="parameter"><code>flags</code></em> :</span></p></td>
 539 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> to create the header with</td>
 540 </tr>
 541 <tr>
 542 <td><p><span class="term"><em class="parameter"><code>length</code></em> :</span></p></td>
 543 <td>a guint pointer to store the header length in</td>
 544 </tr>
 545 <tr>
 546 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 547 <td>a guint8 pointer to store a newly allocated header byte array in</td>
 548 </tr>
 549 <tr>
 550 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 551 <td>a guint8 pointer to store a newly allocated payload byte array in</td>
 552 </tr>
 553 <tr>
 554 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 555 <td>
 556 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the packet was successfully created.</td>
 557 </tr>
 558 </tbody>
 559 </table></div>
 560 </div>
 561 <hr>
 562 <div class="refsect2">
 563 <a name="gst-dp-packet-from-event"></a><h3>gst_dp_packet_from_event ()</h3>
 564 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_packet_from_event            (<em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> *event</code></em>,
 565                                                          <em class="parameter"><code><a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> flags</code></em>,
 566                                                          <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>,
 567                                                          <em class="parameter"><code><span class="type">guint8</span> **header</code></em>,
 568                                                          <em class="parameter"><code><span class="type">guint8</span> **payload</code></em>);</pre>
 569 <div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
 570 <h3 class="title">Warning</h3>
 571 <p><code class="literal">gst_dp_packet_from_event</code> is deprecated and should not be used in newly-written code. use a <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPPacketizer" title="GstDPPacketizer"><span class="type">GstDPPacketizer</span></a></p>
 572 </div>
 573 <p>
 574 Creates a GDP packet from the given event.
 575 </p>
 576 <div class="variablelist"><table border="0">
 577 <col align="left" valign="top">
 578 <tbody>
 579 <tr>
 580 <td><p><span class="term"><em class="parameter"><code>event</code></em> :</span></p></td>
 581 <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> to create a packet for</td>
 582 </tr>
 583 <tr>
 584 <td><p><span class="term"><em class="parameter"><code>flags</code></em> :</span></p></td>
 585 <td>the <a class="link" href="gstreamer-libs-gstdataprotocol.html#GstDPHeaderFlag" title="enum GstDPHeaderFlag"><span class="type">GstDPHeaderFlag</span></a> to create the header with</td>
 586 </tr>
 587 <tr>
 588 <td><p><span class="term"><em class="parameter"><code>length</code></em> :</span></p></td>
 589 <td>a guint pointer to store the header length in</td>
 590 </tr>
 591 <tr>
 592 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 593 <td>a guint8 pointer to store a newly allocated header byte array in</td>
 594 </tr>
 595 <tr>
 596 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 597 <td>a guint8 pointer to store a newly allocated payload byte array in</td>
 598 </tr>
 599 <tr>
 600 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 601 <td>
 602 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the packet was successfully created.</td>
 603 </tr>
 604 </tbody>
 605 </table></div>
 606 </div>
 607 <hr>
 608 <div class="refsect2">
 609 <a name="gst-dp-buffer-from-header"></a><h3>gst_dp_buffer_from_header ()</h3>
 610 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="returnvalue">GstBuffer</span></a> *         gst_dp_buffer_from_header           (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 611                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);</pre>
 612 <p>
 613 Creates a newly allocated <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> from the given header.
 614 The buffer data needs to be copied into it before validating.
 615 </p>
 616 <p>
 617 Use this function if you want to pre-allocate a buffer based on the
 618 packet header to read the packet payload in to.
 619 </p>
 620 <p>
 621 This function does not check the header passed to it, use
 622 <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-header" title="gst_dp_validate_header ()"><code class="function">gst_dp_validate_header()</code></a> first if the header data is unchecked.
 623 </p>
 624 <div class="variablelist"><table border="0">
 625 <col align="left" valign="top">
 626 <tbody>
 627 <tr>
 628 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 629 <td>the length of the packet header</td>
 630 </tr>
 631 <tr>
 632 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 633 <td>the byte array of the packet header</td>
 634 </tr>
 635 <tr>
 636 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 637 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> if the buffer was successfully created, or NULL.</td>
 638 </tr>
 639 </tbody>
 640 </table></div>
 641 </div>
 642 <hr>
 643 <div class="refsect2">
 644 <a name="gst-dp-caps-from-packet"></a><h3>gst_dp_caps_from_packet ()</h3>
 645 <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_dp_caps_from_packet             (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 646                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
 647                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);</pre>
 648 <p>
 649 Creates a newly allocated <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> from the given packet.
 650 </p>
 651 <p>
 652 This function does not check the arguments passed to it, use
 653 <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-packet" title="gst_dp_validate_packet ()"><code class="function">gst_dp_validate_packet()</code></a> first if the header and payload data are
 654 unchecked.
 655 </p>
 656 <div class="variablelist"><table border="0">
 657 <col align="left" valign="top">
 658 <tbody>
 659 <tr>
 660 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 661 <td>the length of the packet header</td>
 662 </tr>
 663 <tr>
 664 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 665 <td>the byte array of the packet header</td>
 666 </tr>
 667 <tr>
 668 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 669 <td>the byte array of the packet payload</td>
 670 </tr>
 671 <tr>
 672 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 673 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> containing the caps represented in the packet,
 674 or NULL if the packet could not be converted.</td>
 675 </tr>
 676 </tbody>
 677 </table></div>
 678 </div>
 679 <hr>
 680 <div class="refsect2">
 681 <a name="gst-dp-event-from-packet"></a><h3>gst_dp_event_from_packet ()</h3>
 682 <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="returnvalue">GstEvent</span></a> *          gst_dp_event_from_packet            (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 683                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
 684                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);</pre>
 685 <p>
 686 Creates a newly allocated <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> from the given packet.
 687 </p>
 688 <p>
 689 This function does not check the arguments passed to it, use
 690 <a class="link" href="gstreamer-libs-gstdataprotocol.html#gst-dp-validate-packet" title="gst_dp_validate_packet ()"><code class="function">gst_dp_validate_packet()</code></a> first if the header and payload data are
 691 unchecked.
 692 </p>
 693 <div class="variablelist"><table border="0">
 694 <col align="left" valign="top">
 695 <tbody>
 696 <tr>
 697 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 698 <td>the length of the packet header</td>
 699 </tr>
 700 <tr>
 701 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 702 <td>the byte array of the packet header</td>
 703 </tr>
 704 <tr>
 705 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 706 <td>the byte array of the packet payload</td>
 707 </tr>
 708 <tr>
 709 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 710 <td>A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a> if the event was successfully created,
 711 or NULL if an event could not be read from the payload.</td>
 712 </tr>
 713 </tbody>
 714 </table></div>
 715 </div>
 716 <hr>
 717 <div class="refsect2">
 718 <a name="gst-dp-validate-header"></a><h3>gst_dp_validate_header ()</h3>
 719 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_validate_header              (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 720                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>);</pre>
 721 <p>
 722 Validates the given packet header by checking the CRC checksum.
 723 </p>
 724 <div class="variablelist"><table border="0">
 725 <col align="left" valign="top">
 726 <tbody>
 727 <tr>
 728 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 729 <td>the length of the packet header</td>
 730 </tr>
 731 <tr>
 732 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 733 <td>the byte array of the packet header</td>
 734 </tr>
 735 <tr>
 736 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 737 <td>
 738 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the CRC matches, or no CRC checksum is present.</td>
 739 </tr>
 740 </tbody>
 741 </table></div>
 742 </div>
 743 <hr>
 744 <div class="refsect2">
 745 <a name="gst-dp-validate-payload"></a><h3>gst_dp_validate_payload ()</h3>
 746 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_validate_payload             (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 747                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
 748                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);</pre>
 749 <p>
 750 Validates the given packet payload using the given packet header
 751 by checking the CRC checksum.
 752 </p>
 753 <div class="variablelist"><table border="0">
 754 <col align="left" valign="top">
 755 <tbody>
 756 <tr>
 757 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 758 <td>the length of the packet header</td>
 759 </tr>
 760 <tr>
 761 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 762 <td>the byte array of the packet header</td>
 763 </tr>
 764 <tr>
 765 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 766 <td>the byte array of the packet payload</td>
 767 </tr>
 768 <tr>
 769 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 770 <td>
 771 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the CRC matches, or no CRC checksum is present.</td>
 772 </tr>
 773 </tbody>
 774 </table></div>
 775 </div>
 776 <hr>
 777 <div class="refsect2">
 778 <a name="gst-dp-validate-packet"></a><h3>gst_dp_validate_packet ()</h3>
 779 <pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            gst_dp_validate_packet              (<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> header_length</code></em>,
 780                                                          <em class="parameter"><code>const <span class="type">guint8</span> *header</code></em>,
 781                                                          <em class="parameter"><code>const <span class="type">guint8</span> *payload</code></em>);</pre>
 782 <p>
 783 Validates the given packet by checking version information and checksums.
 784 </p>
 785 <div class="variablelist"><table border="0">
 786 <col align="left" valign="top">
 787 <tbody>
 788 <tr>
 789 <td><p><span class="term"><em class="parameter"><code>header_length</code></em> :</span></p></td>
 790 <td>the length of the packet header</td>
 791 </tr>
 792 <tr>
 793 <td><p><span class="term"><em class="parameter"><code>header</code></em> :</span></p></td>
 794 <td>the byte array of the packet header</td>
 795 </tr>
 796 <tr>
 797 <td><p><span class="term"><em class="parameter"><code>payload</code></em> :</span></p></td>
 798 <td>the byte array of the packet payload</td>
 799 </tr>
 800 <tr>
 801 <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
 802 <td>
 803 <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the packet validates.</td>
 804 </tr>
 805 </tbody>
 806 </table></div>
 807 </div>
 808 </div>
 809 <div class="refsect1">
 810 <a name="gstreamer-libs-gstdataprotocol.see-also"></a><h2>See Also</h2>
 811 <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a>, <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstEvent.html#GstEvent"><span class="type">GstEvent</span></a>, <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a>
 812 </div>
 813 </div>
 814 <div class="footer">
 815 <hr>
 816           Generated by GTK-Doc V1.18</div>
 817 </body>
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