<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>GstBaseParse</title> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="index.html" title="GStreamer 0.10 Library Reference Manual"> <link rel="up" href="gstreamer-base.html" title="GStreamer Base and Utillity Classes"> <link rel="prev" href="gstreamer-base.html" title="GStreamer Base and Utillity Classes"> <link rel="next" href="GstBaseSrc.html" title="GstBaseSrc"> <meta name="generator" content="GTK-Doc V1.17 (XML mode)"> <link rel="stylesheet" href="style.css" type="text/css"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2"> <tr valign="middle"> <td><a accesskey="p" href="gstreamer-base.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> <td><a accesskey="u" href="gstreamer-base.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td> <td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td> <th width="100%" align="center">GStreamer 0.10 Library Reference Manual</th> <td><a accesskey="n" href="GstBaseSrc.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td> </tr> <tr><td colspan="5" class="shortcuts"> <a href="#gstreamer-libs-GstBaseParse.synopsis" class="shortcut">Top</a> | <a href="#gstreamer-libs-GstBaseParse.description" class="shortcut">Description</a> </td></tr> </table> <div class="refentry"> <a name="gstreamer-libs-GstBaseParse"></a><div class="titlepage"></div> <div class="refnamediv"><table width="100%"><tr> <td valign="top"> <h2><span class="refentrytitle"><a name="gstreamer-libs-GstBaseParse.top_of_page"></a>GstBaseParse</span></h2> <p>GstBaseParse — Base class for stream parsers</p> </td> <td valign="top" align="right"></td> </tr></table></div> <div class="refsynopsisdiv"> <a name="gstreamer-libs-GstBaseParse.synopsis"></a><h2>Synopsis</h2> <pre class="synopsis"> #include <gst/base/gstbaseparse.h> struct <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse">GstBaseParse</a>; struct <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseClass" title="struct GstBaseParseClass">GstBaseParseClass</a>; <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-duration" title="gst_base_parse_set_duration ()">gst_base_parse_set_duration</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> fmt</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> duration</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> interval</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-average-bitrate" title="gst_base_parse_set_average_bitrate ()">gst_base_parse_set_average_bitrate</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> bitrate</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-min-frame-size" title="gst_base_parse_set_min_frame_size ()">gst_base_parse_set_min_frame_size</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> min_size</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-passthrough" title="gst_base_parse_set_passthrough ()">gst_base_parse_set_passthrough</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> passthrough</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-syncable" title="gst_base_parse_set_syncable ()">gst_base_parse_set_syncable</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> syncable</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-has-timing-info" title="gst_base_parse_set_has_timing_info ()">gst_base_parse_set_has_timing_info</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> has_timing</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-frame-rate" title="gst_base_parse_set_frame_rate ()">gst_base_parse_set_frame_rate</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> fps_num</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> fps_den</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> lead_in</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> lead_out</code></em>); <a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-convert-default" title="gst_base_parse_convert_default ()">gst_base_parse_convert_default</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> src_format</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> src_value</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> dest_format</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> *dest_value</code></em>); <a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-add-index-entry" title="gst_base_parse_add_index_entry ()">gst_base_parse_add_index_entry</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> offset</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a> ts</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> key</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> force</code></em>); <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame">GstBaseParseFrame</a>; enum <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrameFlags" title="enum GstBaseParseFrameFlags">GstBaseParseFrameFlags</a>; <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="returnvalue">GstBaseParseFrame</span></a> * <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-new" title="gst_base_parse_frame_new ()">gst_base_parse_frame_new</a> (<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>, <em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrameFlags" title="enum GstBaseParseFrameFlags"><span class="type">GstBaseParseFrameFlags</span></a> flags</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> overhead</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-init" title="gst_base_parse_frame_init ()">gst_base_parse_frame_init</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>); <span class="returnvalue">void</span> <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-free" title="gst_base_parse_frame_free ()">gst_base_parse_frame_free</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>); <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-GstBaseParse.html#gst-base-parse-push-frame" title="gst_base_parse_push_frame ()">gst_base_parse_push_frame</a> (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>); #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-DRAINING:CAPS" title="GST_BASE_PARSE_DRAINING()">GST_BASE_PARSE_DRAINING</a> (parse) #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-FLAG-DRAINING:CAPS" title="GST_BASE_PARSE_FLAG_DRAINING">GST_BASE_PARSE_FLAG_DRAINING</a> #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-FLAG-LOST-SYNC:CAPS" title="GST_BASE_PARSE_FLAG_LOST_SYNC">GST_BASE_PARSE_FLAG_LOST_SYNC</a> #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-FLOW-DROPPED:CAPS" title="GST_BASE_PARSE_FLOW_DROPPED">GST_BASE_PARSE_FLOW_DROPPED</a> #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-FLOW-QUEUED:CAPS" title="GST_BASE_PARSE_FLOW_QUEUED">GST_BASE_PARSE_FLOW_QUEUED</a> #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-LOST-SYNC:CAPS" title="GST_BASE_PARSE_LOST_SYNC()">GST_BASE_PARSE_LOST_SYNC</a> (parse) #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-SINK-PAD:CAPS" title="GST_BASE_PARSE_SINK_PAD()">GST_BASE_PARSE_SINK_PAD</a> (obj) #define <a class="link" href="gstreamer-libs-GstBaseParse.html#GST-BASE-PARSE-SRC-PAD:CAPS" title="GST_BASE_PARSE_SRC_PAD()">GST_BASE_PARSE_SRC_PAD</a> (obj) </pre> </div> <div class="refsect1"> <a name="gstreamer-libs-GstBaseParse.description"></a><h2>Description</h2> <p> This base class is for parser elements that process data and splits it into separate audio/video/whatever frames. </p> <p> It provides for: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"><p>provides one sink pad and one source pad</p></li> <li class="listitem"><p>handles state changes</p></li> <li class="listitem"><p>can operate in pull mode or push mode</p></li> <li class="listitem"><p>handles seeking in both modes</p></li> <li class="listitem"><p>handles events (NEWSEGMENT/EOS/FLUSH)</p></li> <li class="listitem"><p> handles queries (POSITION/DURATION/SEEKING/FORMAT/CONVERT) </p></li> <li class="listitem"><p>handles flushing</p></li> </ul></div> <p> </p> <p> The purpose of this base class is to provide the basic functionality of a parser and share a lot of rather complex code. </p> <p> Description of the parsing mechanism: </p> <div class="orderedlist"><ol class="orderedlist" type="1"> <li class="listitem"><div class="itemizedlist"> <p class="title"><b>Set-up phase</b></p> <ul class="itemizedlist" type="disc"> <li class="listitem"><p> GstBaseParse class calls <em class="parameter"><code>set_sink_caps</code></em> to inform the subclass about incoming sinkpad caps. Subclass should set the srcpad caps accordingly. </p></li> <li class="listitem"><p> GstBaseParse calls <em class="parameter"><code>start</code></em> to inform subclass that data processing is about to start now. </p></li> <li class="listitem"><p> At least at this point subclass needs to tell the GstBaseParse class how big data chunks it wants to receive (min_frame_size). It can do this with <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-min-frame-size" title="gst_base_parse_set_min_frame_size ()"><code class="function">gst_base_parse_set_min_frame_size()</code></a>. </p></li> <li class="listitem"><p> GstBaseParse class sets up appropriate data passing mode (pull/push) and starts to process the data. </p></li> </ul> </div></li> <li class="listitem"><div class="itemizedlist"> <p class="title"><b>Parsing phase</b></p> <ul class="itemizedlist" type="disc"> <li class="listitem"><p> GstBaseParse gathers at least min_frame_size bytes of data either by pulling it from upstream or collecting buffers in an internal <a class="link" href="GstAdapter.html" title="GstAdapter"><span class="type">GstAdapter</span></a>. </p></li> <li class="listitem"><p> A buffer of (at least) min_frame_size bytes is passed to subclass with <em class="parameter"><code>check_valid_frame</code></em>. Subclass checks the contents and returns TRUE if the buffer contains a valid frame. It also needs to set the <em class="parameter"><code>framesize</code></em> according to the detected frame size. If buffer didn't contain a valid frame, this call must return FALSE and optionally set the <em class="parameter"><code>skipsize</code></em> value to inform base class that how many bytes it needs to skip in order to find a valid frame. <em class="parameter"><code>framesize</code></em> can always indicate a new minimum for current frame parsing. The passed buffer is read-only. Note that <em class="parameter"><code>check_valid_frame</code></em> might receive any small amount of input data when leftover data is being drained (e.g. at EOS). </p></li> <li class="listitem"><p> After valid frame is found, it will be passed again to subclass with <em class="parameter"><code>parse_frame</code></em> call. Now subclass is responsible for parsing the frame contents and setting the caps, and buffer metadata (e.g. buffer timestamp and duration, or keyframe if applicable). (although the latter can also be done by GstBaseParse if it is appropriately configured, see below). Frame is provided with timestamp derived from upstream (as much as generally possible), duration obtained from configuration (see below), and offset if meaningful (in pull mode). </p></li> <li class="listitem"><p> Finally the buffer can be pushed downstream and the parsing loop starts over again. Just prior to actually pushing the buffer in question, it is passed to <em class="parameter"><code>pre_push_buffer</code></em> which gives subclass yet one last chance to examine buffer metadata, or to send some custom (tag) events, or to perform custom (segment) filtering. </p></li> <li class="listitem"><p> During the parsing process GstBaseParseClass will handle both srcpad and sinkpad events. They will be passed to subclass if <em class="parameter"><code>event</code></em> or <em class="parameter"><code>src_event</code></em> callbacks have been provided. </p></li> </ul> </div></li> <li class="listitem"><div class="itemizedlist"> <p class="title"><b>Shutdown phase</b></p> <ul class="itemizedlist" type="disc"><li class="listitem"><p> GstBaseParse class calls <em class="parameter"><code>stop</code></em> to inform the subclass that data parsing will be stopped. </p></li></ul> </div></li> </ol></div> <p> </p> <p> Subclass is responsible for providing pad template caps for source and sink pads. The pads need to be named "sink" and "src". It also needs to set the fixed caps on srcpad, when the format is ensured (e.g. when base class calls subclass' <em class="parameter"><code>set_sink_caps</code></em> function). </p> <p> This base class uses <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GST-FORMAT-DEFAULT:CAPS"><span class="type">GST_FORMAT_DEFAULT</span></a> as a meaning of frames. So, subclass conversion routine needs to know that conversion from <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GST-FORMAT-TIME:CAPS"><span class="type">GST_FORMAT_TIME</span></a> to <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GST-FORMAT-DEFAULT:CAPS"><span class="type">GST_FORMAT_DEFAULT</span></a> must return the frame number that can be found from the given byte position. </p> <p> GstBaseParse uses subclasses conversion methods also for seeking (or otherwise uses its own default one, see also below). </p> <p> Subclass <em class="parameter"><code>start</code></em> and <em class="parameter"><code>stop</code></em> functions will be called to inform the beginning and end of data processing. </p> <p> Things that subclass need to take care of: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"><p>Provide pad templates</p></li> <li class="listitem"><p> Fixate the source pad caps when appropriate </p></li> <li class="listitem"><p> Inform base class how big data chunks should be retrieved. This is done with <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-min-frame-size" title="gst_base_parse_set_min_frame_size ()"><code class="function">gst_base_parse_set_min_frame_size()</code></a> function. </p></li> <li class="listitem"><p> Examine data chunks passed to subclass with <em class="parameter"><code>check_valid_frame</code></em> and tell if they contain a valid frame </p></li> <li class="listitem"><p> Set the caps and timestamp to frame that is passed to subclass with <em class="parameter"><code>parse_frame</code></em> function. </p></li> <li class="listitem"><p>Provide conversion functions</p></li> <li class="listitem"><p> Update the duration information with <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-duration" title="gst_base_parse_set_duration ()"><code class="function">gst_base_parse_set_duration()</code></a> </p></li> <li class="listitem"><p> Optionally passthrough using <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-passthrough" title="gst_base_parse_set_passthrough ()"><code class="function">gst_base_parse_set_passthrough()</code></a> </p></li> <li class="listitem"><p> Configure various baseparse parameters using <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-average-bitrate" title="gst_base_parse_set_average_bitrate ()"><code class="function">gst_base_parse_set_average_bitrate()</code></a>, <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-syncable" title="gst_base_parse_set_syncable ()"><code class="function">gst_base_parse_set_syncable()</code></a> and <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-frame-rate" title="gst_base_parse_set_frame_rate ()"><code class="function">gst_base_parse_set_frame_rate()</code></a>. </p></li> <li class="listitem"><p> In particular, if subclass is unable to determine a duration, but parsing (or specs) yields a frames per seconds rate, then this can be provided to GstBaseParse to enable it to cater for buffer time metadata (which will be taken from upstream as much as possible). Internally keeping track of frame durations and respective sizes that have been pushed provides GstBaseParse with an estimated bitrate. A default <em class="parameter"><code>convert</code></em> (used if not overriden) will then use these rates to perform obvious conversions. These rates are also used to update (estimated) duration at regular frame intervals. </p></li> </ul></div> <p> </p> </div> <div class="refsect1"> <a name="gstreamer-libs-GstBaseParse.details"></a><h2>Details</h2> <div class="refsect2"> <a name="GstBaseParse"></a><h3>struct GstBaseParse</h3> <pre class="programlisting">struct GstBaseParse { GstElement element; }; </pre> <p> The opaque <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> data structure. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a> <em class="structfield"><code><a name="GstBaseParse.element"></a>element</code></em>;</span></p></td> <td>the parent element.</td> </tr></tbody> </table></div> </div> <hr> <div class="refsect2"> <a name="GstBaseParseClass"></a><h3>struct GstBaseParseClass</h3> <pre class="programlisting">struct GstBaseParseClass { GstElementClass parent_class; /* virtual methods for subclasses */ gboolean (*start) (GstBaseParse * parse); gboolean (*stop) (GstBaseParse * parse); gboolean (*set_sink_caps) (GstBaseParse * parse, GstCaps * caps); gboolean (*check_valid_frame) (GstBaseParse * parse, GstBaseParseFrame * frame, guint * framesize, gint * skipsize); GstFlowReturn (*parse_frame) (GstBaseParse * parse, GstBaseParseFrame * frame); GstFlowReturn (*pre_push_frame) (GstBaseParse * parse, GstBaseParseFrame * frame); gboolean (*convert) (GstBaseParse * parse, GstFormat src_format, gint64 src_value, GstFormat dest_format, gint64 * dest_value); gboolean (*event) (GstBaseParse * parse, GstEvent * event); gboolean (*src_event) (GstBaseParse * parse, GstEvent * event); }; </pre> <p> Subclasses can override any of the available virtual methods or not, as needed. At minimum <em class="parameter"><code>check_valid_frame</code></em> and <em class="parameter"><code>parse_frame</code></em> needs to be overridden. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#GstElementClass"><span class="type">GstElementClass</span></a> <em class="structfield"><code><a name="GstBaseParseClass.parent-class"></a>parent_class</code></em>;</span></p></td> <td>the parent class</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.start"></a>start</code></em> ()</span></p></td> <td>Optional. Called when the element starts processing. Allows opening external resources.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.stop"></a>stop</code></em> ()</span></p></td> <td>Optional. Called when the element stops processing. Allows closing external resources.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.set-sink-caps"></a>set_sink_caps</code></em> ()</span></p></td> <td>allows the subclass to be notified of the actual caps set.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.check-valid-frame"></a>check_valid_frame</code></em> ()</span></p></td> <td>Check if the given piece of data contains a valid frame.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.parse-frame"></a>parse_frame</code></em> ()</span></p></td> <td>Parse the already checked frame. Subclass need to set the buffer timestamp, duration, caps and possibly other necessary metadata. This is called with srcpad's STREAM_LOCK held.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.pre-push-frame"></a>pre_push_frame</code></em> ()</span></p></td> <td>Optional. Called just prior to pushing a frame (after any pending events have been sent) to give subclass a chance to perform additional actions at this time (e.g. tag sending) or to decide whether this buffer should be dropped or not (e.g. custom segment clipping).</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.convert"></a>convert</code></em> ()</span></p></td> <td>Optional. Convert between formats.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.event"></a>event</code></em> ()</span></p></td> <td>Optional. Event handler on the sink pad. This function should return TRUE if the event was handled and can be dropped.</td> </tr> <tr> <td><p><span class="term"><em class="structfield"><code><a name="GstBaseParseClass.src-event"></a>src_event</code></em> ()</span></p></td> <td>Optional. Event handler on the source pad. Should return TRUE if the event was handled and can be dropped.</td> </tr> </tbody> </table></div> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-duration"></a><h3>gst_base_parse_set_duration ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_duration (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> fmt</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> duration</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> interval</code></em>);</pre> <p> Sets the duration of the currently playing media. Subclass can use this when it is able to determine duration and/or notices a change in the media duration. Alternatively, if <em class="parameter"><code>interval</code></em> is non-zero (default), then stream duration is determined based on estimated bitrate, and updated every <em class="parameter"><code>interval</code></em> frames. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>fmt</code></em> :</span></p></td> <td> <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>duration</code></em> :</span></p></td> <td>duration value.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>interval</code></em> :</span></p></td> <td>how often to update the duration estimate based on bitrate, or 0.</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-average-bitrate"></a><h3>gst_base_parse_set_average_bitrate ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_average_bitrate (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> bitrate</code></em>);</pre> <p> Optionally sets the average bitrate detected in media (if non-zero), e.g. based on metadata, as it will be posted to the application. </p> <p> By default, announced average bitrate is estimated. The average bitrate is used to estimate the total duration of the stream and to estimate a seek position, if there's no index and the format is syncable (see <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-set-syncable" title="gst_base_parse_set_syncable ()"><code class="function">gst_base_parse_set_syncable()</code></a>). </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>bitrate</code></em> :</span></p></td> <td>average bitrate in bits/second</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-min-frame-size"></a><h3>gst_base_parse_set_min_frame_size ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_min_frame_size (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> min_size</code></em>);</pre> <p> Subclass can use this function to tell the base class that it needs to give at least <span class="type">min_size</span> buffers. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>min_size</code></em> :</span></p></td> <td>Minimum size of the data that this base class should give to subclass.</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-passthrough"></a><h3>gst_base_parse_set_passthrough ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_passthrough (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> passthrough</code></em>);</pre> <p> Set if the nature of the format or configuration does not allow (much) parsing, and the parser should operate in passthrough mode (which only applies when operating in push mode). That is, incoming buffers are pushed through unmodified, i.e. no <em class="parameter"><code>check_valid_frame</code></em> or <em class="parameter"><code>parse_frame</code></em> callbacks will be invoked, but <em class="parameter"><code>pre_push_buffer</code></em> will still be invoked, so subclass can perform as much or as little is appropriate for passthrough semantics in <em class="parameter"><code>pre_push_buffer</code></em>. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> </td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>passthrough</code></em> :</span></p></td> <td> <a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if parser should run in passthrough mode</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-syncable"></a><h3>gst_base_parse_set_syncable ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_syncable (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> syncable</code></em>);</pre> <p> Set if frame starts can be identified. This is set by default and determines whether seeking based on bitrate averages is possible for a format/stream. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> </td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>syncable</code></em> :</span></p></td> <td>set if frame starts can be identified</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-has-timing-info"></a><h3>gst_base_parse_set_has_timing_info ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_has_timing_info (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> has_timing</code></em>);</pre> <p> Set if frames carry timing information which the subclass can (generally) parse and provide. In particular, intrinsic (rather than estimated) time can be obtained following a seek. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> </td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>has_timing</code></em> :</span></p></td> <td>whether frames carry timing information</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-set-frame-rate"></a><h3>gst_base_parse_set_frame_rate ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_set_frame_rate (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> fps_num</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> fps_den</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> lead_in</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> lead_out</code></em>);</pre> <p> If frames per second is configured, parser can take care of buffer duration and timestamping. When performing segment clipping, or seeking to a specific location, a corresponding decoder might need an initial <em class="parameter"><code>lead_in</code></em> and a following <em class="parameter"><code>lead_out</code></em> number of frames to ensure the desired segment is entirely filled upon decoding. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>the <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> to set</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>fps_num</code></em> :</span></p></td> <td>frames per second (numerator).</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>fps_den</code></em> :</span></p></td> <td>frames per second (denominator).</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>lead_in</code></em> :</span></p></td> <td>frames needed before a segment for subsequent decode</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>lead_out</code></em> :</span></p></td> <td>frames needed after a segment</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-convert-default"></a><h3>gst_base_parse_convert_default ()</h3> <pre class="programlisting"><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_base_parse_convert_default (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> src_format</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> src_value</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> dest_format</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint64"><span class="type">gint64</span></a> *dest_value</code></em>);</pre> <p> Default implementation of "convert" vmethod in <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> class. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>src_format</code></em> :</span></p></td> <td> <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> describing the source format.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>src_value</code></em> :</span></p></td> <td>Source value to be converted.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>dest_format</code></em> :</span></p></td> <td> <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstFormat.html#GstFormat"><span class="type">GstFormat</span></a> defining the converted format.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>dest_value</code></em> :</span></p></td> <td>Pointer where the conversion result will be put.</td> </tr> <tr> <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> <td>TRUE if conversion was successful.</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-add-index-entry"></a><h3>gst_base_parse_add_index_entry ()</h3> <pre class="programlisting"><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_base_parse_add_index_entry (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint64"><span class="type">guint64</span></a> offset</code></em>, <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstClock.html#GstClockTime"><span class="type">GstClockTime</span></a> ts</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> key</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> force</code></em>);</pre> <p> Adds an entry to the index associating <em class="parameter"><code>offset</code></em> to <em class="parameter"><code>ts</code></em>. It is recommended to only add keyframe entries. <em class="parameter"><code>force</code></em> allows to bypass checks, such as whether the stream is (upstream) seekable, another entry is already "close" to the new entry, etc. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>offset</code></em> :</span></p></td> <td>offset of entry</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>ts</code></em> :</span></p></td> <td>timestamp associated with offset</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>key</code></em> :</span></p></td> <td>whether entry refers to keyframe</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>force</code></em> :</span></p></td> <td>add entry disregarding sanity checks</td> </tr> <tr> <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> <td> <a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> indicating whether entry was added</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GstBaseParseFrame"></a><h3>GstBaseParseFrame</h3> <pre class="programlisting">typedef struct { GstBuffer * buffer; guint flags; gint overhead; } GstBaseParseFrame; </pre> <p> Frame (context) data passed to each frame parsing virtual methods. In addition to providing the data to be checked for a valid frame or an already identified frame, it conveys additional metadata or control information from and to the subclass w.r.t. the particular frame in question (rather than global parameters). Some of these may apply to each parsing stage, others only to some a particular one. These parameters are effectively zeroed at start of each frame's processing, i.e. parsing virtual method invocation sequence. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> *<em class="structfield"><code><a name="GstBaseParseFrame.buffer"></a>buffer</code></em>;</span></p></td> <td>data to check for valid frame or parsed frame. Subclass is allowed to replace this buffer.</td> </tr> <tr> <td><p><span class="term"><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> <em class="structfield"><code><a name="GstBaseParseFrame.flags"></a>flags</code></em>;</span></p></td> <td>a combination of input and output <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrameFlags" title="enum GstBaseParseFrameFlags"><span class="type">GstBaseParseFrameFlags</span></a> that convey additional context to subclass or allow subclass to tune subsequent <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> actions.</td> </tr> <tr> <td><p><span class="term"><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> <em class="structfield"><code><a name="GstBaseParseFrame.overhead"></a>overhead</code></em>;</span></p></td> <td>subclass can set this to indicates the metadata overhead for the given frame, which is then used to enable more accurate bitrate computations. If this is -1, it is assumed that this frame should be skipped in bitrate calculation.</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GstBaseParseFrameFlags"></a><h3>enum GstBaseParseFrameFlags</h3> <pre class="programlisting">typedef enum { GST_BASE_PARSE_FRAME_FLAG_NONE = 0, GST_BASE_PARSE_FRAME_FLAG_NO_FRAME = (1 << 0), GST_BASE_PARSE_FRAME_FLAG_CLIP = (1 << 1) } GstBaseParseFrameFlags; </pre> <p> Flags to be used in a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a>. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><a name="GST-BASE-PARSE-FRAME-FLAG-NONE:CAPS"></a><span class="term"><code class="literal">GST_BASE_PARSE_FRAME_FLAG_NONE</code></span></p></td> <td>no flag </td> </tr> <tr> <td><p><a name="GST-BASE-PARSE-FRAME-FLAG-NO-FRAME:CAPS"></a><span class="term"><code class="literal">GST_BASE_PARSE_FRAME_FLAG_NO_FRAME</code></span></p></td> <td>set to indicate this buffer should not be counted as frame, e.g. if this frame is dependent on a previous one. As it is not counted as a frame, bitrate increases but frame to time conversions are maintained. </td> </tr> <tr> <td><p><a name="GST-BASE-PARSE-FRAME-FLAG-CLIP:CAPS"></a><span class="term"><code class="literal">GST_BASE_PARSE_FRAME_FLAG_CLIP</code></span></p></td> <td> <em class="parameter"><code>pre_push_buffer</code></em> can set this to indicate that regular segment clipping can still be performed (as opposed to any custom one having been done). </td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-frame-new"></a><h3>gst_base_parse_frame_new ()</h3> <pre class="programlisting"><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="returnvalue">GstBaseParseFrame</span></a> * gst_base_parse_frame_new (<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>, <em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrameFlags" title="enum GstBaseParseFrameFlags"><span class="type">GstBaseParseFrameFlags</span></a> flags</code></em>, <em class="parameter"><code><a href="/home/kou/work/ruby/ruby-gnome2.win32/glib2/vendor/local/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> overhead</code></em>);</pre> <p> Allocates a new <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a>. This function is mainly for bindings, elements written in C should usually allocate the frame on the stack and then use <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-init" title="gst_base_parse_frame_init ()"><code class="function">gst_base_parse_frame_init()</code></a> to initialise it. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>buffer</code></em> :</span></p></td> <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a>. <span class="annotation">[<acronym title="Don't free data after the code is done."><span class="acronym">transfer none</span></acronym>]</span> </td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>flags</code></em> :</span></p></td> <td>the flags</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>overhead</code></em> :</span></p></td> <td>number of bytes in this frame which should be counted as metadata overhead, ie. not used to calculate the average bitrate. Set to -1 to mark the entire frame as metadata. If in doubt, set to 0.</td> </tr> <tr> <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> <td>a newly-allocated <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a>. Free with <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-free" title="gst_base_parse_frame_free ()"><code class="function">gst_base_parse_frame_free()</code></a> when no longer needed, unless you gave away ownership to <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-push-frame" title="gst_base_parse_push_frame ()"><code class="function">gst_base_parse_push_frame()</code></a>.</td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-frame-init"></a><h3>gst_base_parse_frame_init ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_frame_init (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>);</pre> <p> Sets a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> to initial state. Currently this means all public fields are zero-ed and a private flag is set to make sure <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-free" title="gst_base_parse_frame_free ()"><code class="function">gst_base_parse_frame_free()</code></a> only frees the contents but not the actual frame. Use this function to initialise a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> allocated on the stack. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><em class="parameter"><code>frame</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a>.</td> </tr></tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-frame-free"></a><h3>gst_base_parse_frame_free ()</h3> <pre class="programlisting"><span class="returnvalue">void</span> gst_base_parse_frame_free (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>);</pre> </div> <hr> <div class="refsect2"> <a name="gst-base-parse-push-frame"></a><h3>gst_base_parse_push_frame ()</h3> <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a> gst_base_parse_push_frame (<em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a> *parse</code></em>, <em class="parameter"><code><a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a> *frame</code></em>);</pre> <p> Pushes the frame downstream, sends any pending events and does some timestamp and segment handling. Takes ownership of <em class="parameter"><code>frame</code></em> and will clear it (if it was initialised with <a class="link" href="gstreamer-libs-GstBaseParse.html#gst-base-parse-frame-init" title="gst_base_parse_frame_init ()"><code class="function">gst_base_parse_frame_init()</code></a>) or free it. </p> <p> This must be called with sinkpad STREAM_LOCK held. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody> <tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td> <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParse" title="struct GstBaseParse"><span class="type">GstBaseParse</span></a>.</td> </tr> <tr> <td><p><span class="term"><em class="parameter"><code>frame</code></em> :</span></p></td> <td>a <a class="link" href="gstreamer-libs-GstBaseParse.html#GstBaseParseFrame" title="GstBaseParseFrame"><span class="type">GstBaseParseFrame</span></a>. <span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span> </td> </tr> <tr> <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> <td><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="type">GstFlowReturn</span></a></td> </tr> </tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-DRAINING:CAPS"></a><h3>GST_BASE_PARSE_DRAINING()</h3> <pre class="programlisting">#define GST_BASE_PARSE_DRAINING(parse) (!!(GST_BASE_PARSE_CAST(parse)->flags & GST_BASE_PARSE_FLAG_DRAINING)) </pre> <p> Obtains current drain status (ie. whether EOS has been received and the parser is now processing the frames at the end of the stream) </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>base parse instance</td> </tr></tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-FLAG-DRAINING:CAPS"></a><h3>GST_BASE_PARSE_FLAG_DRAINING</h3> <pre class="programlisting">#define GST_BASE_PARSE_FLAG_DRAINING (1 << 1) </pre> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-FLAG-LOST-SYNC:CAPS"></a><h3>GST_BASE_PARSE_FLAG_LOST_SYNC</h3> <pre class="programlisting">#define GST_BASE_PARSE_FLAG_LOST_SYNC (1 << 0) </pre> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-FLOW-DROPPED:CAPS"></a><h3>GST_BASE_PARSE_FLOW_DROPPED</h3> <pre class="programlisting">#define GST_BASE_PARSE_FLOW_DROPPED GST_FLOW_CUSTOM_SUCCESS </pre> <p> A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="type">GstFlowReturn</span></a> that can be returned from parse_frame to indicate that no output buffer was generated, or from pre_push_buffer to to forego pushing buffer. </p> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-FLOW-QUEUED:CAPS"></a><h3>GST_BASE_PARSE_FLOW_QUEUED</h3> <pre class="programlisting">#define GST_BASE_PARSE_FLOW_QUEUED GST_FLOW_CUSTOM_SUCCESS_1 </pre> <p> A <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="type">GstFlowReturn</span></a> that can be returned from parse frame to indicate that the buffer will be queued to be pushed when the next OK </p> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-LOST-SYNC:CAPS"></a><h3>GST_BASE_PARSE_LOST_SYNC()</h3> <pre class="programlisting">#define GST_BASE_PARSE_LOST_SYNC(parse) (!!(GST_BASE_PARSE_CAST(parse)->flags & GST_BASE_PARSE_FLAG_LOST_SYNC)) </pre> <p> Obtains current sync status. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><em class="parameter"><code>parse</code></em> :</span></p></td> <td>base parse instance</td> </tr></tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-SINK-PAD:CAPS"></a><h3>GST_BASE_PARSE_SINK_PAD()</h3> <pre class="programlisting">#define GST_BASE_PARSE_SINK_PAD(obj) (GST_BASE_PARSE_CAST (obj)->sinkpad) </pre> <p> Gives the pointer to the sink <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a> object of the element. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td> <td>base parse instance</td> </tr></tbody> </table></div> <p class="since">Since 0.10.33</p> </div> <hr> <div class="refsect2"> <a name="GST-BASE-PARSE-SRC-PAD:CAPS"></a><h3>GST_BASE_PARSE_SRC_PAD()</h3> <pre class="programlisting">#define GST_BASE_PARSE_SRC_PAD(obj) (GST_BASE_PARSE_CAST (obj)->srcpad) </pre> <p> Gives the pointer to the source <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a> object of the element. </p> <div class="variablelist"><table border="0"> <col align="left" valign="top"> <tbody><tr> <td><p><span class="term"><em class="parameter"><code>obj</code></em> :</span></p></td> <td>base parse instance</td> </tr></tbody> </table></div> <p class="since">Since 0.10.33</p> </div> </div> <div class="refsect1"> <a name="gstreamer-libs-GstBaseParse.see-also"></a><h2>See Also</h2> <a class="link" href="GstBaseTransform.html" title="GstBaseTransform"><span class="type">GstBaseTransform</span></a> </div> </div> <div class="footer"> <hr> Generated by GTK-Doc V1.17</div> </body> </html>