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4439f8157b
Original commit message from CVS: add licensing advisory information to plugin writers guide
195 lines
7.5 KiB
XML
195 lines
7.5 KiB
XML
<?xml version='1.0'?>
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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
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<!ENTITY % image-entities SYSTEM "image.entities">
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%image-entities;
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<!ENTITY % version-entities SYSTEM "version.entities">
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%version-entities;
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<!ENTITY TITLEPAGE SYSTEM "titlepage.xml">
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<!ENTITY INTRO_PREFACE SYSTEM "intro-preface.xml">
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<!ENTITY INTRO_BASICS SYSTEM "intro-basics.xml">
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<!ENTITY BUILDING_BOILER SYSTEM "building-boiler.xml">
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<!ENTITY BUILDING_DEBUG SYSTEM "building-debug.xml">
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<!ENTITY BUILDING_PADS SYSTEM "building-pads.xml">
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<!ENTITY BUILDING_CHAINFN SYSTEM "building-chainfn.xml">
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<!ENTITY BUILDING_STATE SYSTEM "building-state.xml">
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<!ENTITY BUILDING_PROPS SYSTEM "building-props.xml">
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<!ENTITY BUILDING_SIGNALS SYSTEM "building-signals.xml">
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<!ENTITY BUILDING_TESTAPP SYSTEM "building-testapp.xml">
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<!ENTITY BUILDING_FILTERFACT SYSTEM "building-filterfactory.xml">
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<!ENTITY ADVANCED_SCHEDULING SYSTEM "advanced-scheduling.xml">
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<!ENTITY ADVANCED_TYPES SYSTEM "advanced-types.xml">
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<!ENTITY ADVANCED_REQUEST SYSTEM "advanced-request.xml">
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<!ENTITY ADVANCED_CLOCK SYSTEM "advanced-clock.xml">
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<!ENTITY ADVANCED_DPARAMS SYSTEM "advanced-dparams.xml">
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<!ENTITY ADVANCED_MIDI SYSTEM "advanced-midi.xml">
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<!ENTITY ADVANCED_INTERFACES SYSTEM "advanced-interfaces.xml">
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<!ENTITY ADVANCED_TAGGING SYSTEM "advanced-tagging.xml">
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<!ENTITY ADVANCED_EVENTS SYSTEM "advanced-events.xml">
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<!ENTITY OTHER_SOURCE SYSTEM "other-source.xml">
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<!ENTITY OTHER_SINK SYSTEM "other-sink.xml">
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<!ENTITY OTHER_ONETON SYSTEM "other-oneton.xml">
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<!ENTITY OTHER_NTOONE SYSTEM "other-ntoone.xml">
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<!ENTITY OTHER_NTON SYSTEM "other-nton.xml">
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<!ENTITY OTHER_AUTOPLUGGER SYSTEM "other-autoplugger.xml">
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<!ENTITY OTHER_MANAGER SYSTEM "other-manager.xml">
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<!ENTITY APPENDIX_CHECKLIST SYSTEM "appendix-checklist.xml">
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<!ENTITY APPENDIX_LICENSING SYSTEM "appendix-licensing.xml">
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<!ENTITY APPENDIX_PYTHON SYSTEM "appendix-python.xml">
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<!ENTITY GStreamer "<application>GStreamer</application>">
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<!ENTITY GstAppDevMan "<emphasis>GStreamer Application Development Manual</emphasis>">
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<!ENTITY GstLibRef "<emphasis>GStreamer Library Reference</emphasis>">
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]>
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<book id="index">
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&TITLEPAGE;
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<!-- ############# part ############### -->
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<part id="part-introduction" xreflabel="Introduction">
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<title>Introduction</title>
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<partintro>
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<para>
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&GStreamer; is an exremely powerful and versatile framework for creating
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streaming media applications. Many of the virtues of the &GStreamer;
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framework come from its modularity: &GStreamer; can seamlessly
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incorporate new plugin modules. But because modularity and power often
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come at a cost of greater complexity (consider, for example, <ulink
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type="http" url="http://www.omg.org/">CORBA</ulink>), writing new
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plugins is not always easy.
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</para>
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<para>
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This guide is intended to help you understand the &GStreamer; framework
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(version &GST_VERSION;) so you can develop new plugins to extend the
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existing functionality. The guide addresses most issues by following the
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development of an example plugin - an audio filter plugin -
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written in C. However, the later parts of the guide also present some
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issues involved in writing other types of plugins, and the end of the
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guide describes some of the Python bindings for &GStreamer;.
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</para>
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</partintro>
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&INTRO_PREFACE;
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&INTRO_BASICS;
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</part>
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<!-- ############ part ############# -->
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<part id="part-building" xreflabel="Building a Plugin">
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<title>Building a Plugin</title>
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<partintro>
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<para>
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You are now ready to learn how to build a plugin. In this part of the
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guide, you will learn how to apply basic &GStreamer;
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programming concepts to write a simple plugin. The previous parts of the
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guide have contained no explicit example code, perhaps making things a
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bit abstract and difficult to understand. In contrast, this section will
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present both applications and code by following the development of an
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example audio filter plugin called <quote>ExampleFilter</quote>.
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</para>
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<para>
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The example filter element will begin with a single input pad and a
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single
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output pad. The filter will, at first, simply pass media and event data
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from its sink pad to its source pad without modification. But by the end
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of this part of the guide, you will learn to add some more interesting
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functionality, including properties and signal handlers. And after
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reading the next part of the guide, <xref linkend="part-advanced"/>, you
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will be able to add even more functionality to your plugins.
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</para>
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<para>
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The example code used in this part of the guide can be found in
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<filename class="directory">examples/pwg/examplefilter/</filename> in
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your &GStreamer; directory.
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</para>
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</partintro>
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&BUILDING_BOILER;
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&BUILDING_PADS;
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&BUILDING_CHAINFN;
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&BUILDING_STATE;
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&BUILDING_PROPS;
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&BUILDING_SIGNALS;
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&BUILDING_TESTAPP;
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&BUILDING_FILTERFACT;
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</part>
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<!-- ############ part ############# -->
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<part id="part-advanced" xreflabel="Advanced Filter Concepts">
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<title>Advanced Filter Concepts</title>
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<partintro>
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<para>
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By now, you should be able to create basic filter elements that can
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receive and send data. This is the simple model that &GStreamer; stands
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for. But &GStreamer; can do much more than only this! In this chapter,
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various advanced topics will be discussed, such as scheduling, special
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pad types, clocking, events, interfaces, tagging and more. These topics
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are the sugar that makes &GStreamer; so easy to use for applications.
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</para>
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</partintro>
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&ADVANCED_SCHEDULING;
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&ADVANCED_TYPES;
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&ADVANCED_REQUEST;
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&ADVANCED_CLOCK;
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&ADVANCED_DPARAMS;
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&ADVANCED_MIDI;
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&ADVANCED_INTERFACES;
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&ADVANCED_TAGGING;
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&ADVANCED_EVENTS;
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<!-- FIXME: add querying, event handling and conversion -->
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</part>
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<!-- ############ part ############# -->
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<part id="part-other" xreflabel="Other Element Types">
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<title>Other Element Types</title>
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<partintro>
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<para>
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By now, we have looked at pretty much any feature that can be embedded
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into a &GStreamer; element. However, we have limited ourselves to the
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simple model of a filter element. In this chapter, we will look at the
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specific difficulties and things to keep in mind when writing specific
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types of elements. We will discuss output elements (sinks), input
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elements (sources), 1-to-N elements, N-to-1 elements, N-to-N elements,
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autopluggers and managers. Some of these represent elements that don't
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actually exist. Rather, they represent a general concept.
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</para>
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</partintro>
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&OTHER_SOURCE;
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&OTHER_SINK;
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&OTHER_ONETON;
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&OTHER_NTOONE;
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&OTHER_NTON;
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&OTHER_AUTOPLUGGER;
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&OTHER_MANAGER;
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</part>
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<!-- ############ part ############# -->
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<part id="part-appendix" xreflabel="Appendices">
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<title>Appendices</title>
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<partintro>
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<para>
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This chapter contains things that don't belong anywhere else.
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</para>
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</partintro>
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&APPENDIX_CHECKLIST;
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&APPENDIX_LICENSING;
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&APPENDIX_PYTHON;
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</part>
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</book>
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