%image-entities;
%version-entities;
%url-entities;
The code for this example is automatically extracted from
the documentation and built under examples/manual
in the GStreamer tarball.
">
GStreamer">
]>
Wim
Taymans
wim.taymans@chello.be
Steve
Baker
stevebaker_org@yahoo.co.uk
Andy
Wingo
wingo@pobox.com
Ronald
S.
Bultje
rbultje@ronald.bitfreak.net
This material may be distributed only subject to the terms and
conditions set forth in the Open Publication License, v1.0 or later (the
latest version is presently available at http://www.opencontent.org/opl.shtml).
&GStreamer; Application Development Manual (&GST_VERSION;)
Overview
&GStreamer; is an exremely powerful and versatile framework for
creating streaming media applications. Many of the virtues of the
&GStreamer; framework come from its modularity: &GStreamer; can
seamlessly incorporate new plugin modules. But because modularity
and power often come at a cost of greater complexity (consider,
for example, CORBA), writing new
applications is not always easy.
This guide is intended to help you understand the &GStreamer;
framework (version &GST_VERSION;) so you can develop applications
based on it. The first chapters will focus on development of a
simple audio player, with much effort going into helping you
understand &GStreamer; concepts. Later chapters will go into
more advanced topics related to media playback, but also at
other forms of media processing (capture, editing, etc.).
&INTRO;
&MOTIVATION;
&CONCEPTS;
Basic Concepts
In these chapters, we will discuss the basic concepts of &GStreamer;
and the most-used objects, such as elements, pads and buffers. We
will use a visual representation of these objects so that we can
visualize the more complex pipelines you will learn to build later
on. You will get a first glance at the &GStreamer; API, which should
be enough for building elementary applications. Later on in this
part, you will also learn to build a basic command-line application.
Note that this part will give a look into the low-level API and
concepts of &GStreamer;. Once you're going to build applications,
you might want to use higher-level APIs. Those will be discussed
later on in this manual.
&INIT;
&ELEMENTS;
&BINS;
&BUS;
&PADS;
&DATA;
&HELLOWORLD;
Advanced &GStreamer; concepts
In this part we will cover the more advanced features of &GStreamer;.
With the basics you learned in the previous part you should be
able to create a simple application. However,
&GStreamer; provides much more candy than just the basics of playing
back audio files. In this chapter, you will learn more of the
low-level features and internals of &GStreamer;.
Some parts of this part will serve mostly as an explanation of
how &GStreamer; works internally; they are not actually needed for
actual application development. This includes chapter such as the
ones covering scheduling, autoplugging and synchronization. Other
chapters, however, discuss more advanced ways of
pipeline-application interaction, and can turn out to be very useful
for certain applications. This includes the chapters on metadata,
querying and events, interfaces, dynamic parameters and pipeline
data manipulation.
&QUERYEVENTS;
&METADATA;
&INTERFACES;
&CLOCKS;
&DPARAMS;
&THREADS;
&AUTOPLUGGING;
&DATAACCESS;
Higher-level interfaces for &GStreamer; applications
In the previous two parts, you have learned many of the internals
and their corresponding low-level interfaces into &GStreamer;
application programming. Many people will, however, not need so
much control (and as much code), but will prefer to use a standard
playback interface that does most of the difficult internals for
them. In this chapter, we will introduce you into the concept of
autopluggers, playback managing elements, XML-based pipelines and
other such things. Those higher-level interfaces are intended to
simplify &GStreamer;-based application programming. They do, however,
also reduce the flexibility. It is up to the application developer
to choose which interface he will want to use.
&COMPONENTS;
&XML;
Appendices
By now, you've learned all about the internals of &GStreamer; and
application programming using the &GStreamer; framework. This part
will go into some random bits that are useful to know if you're
going to use &GStreamer; for serious application programming. It
will touch upon things related to integration with popular desktop
environments that we run on (GNOME, KDE, OS X, Windows), it will
shortly explain how applications included with &GStreamer; can help
making your life easier, and some information on debugging.
In addition, we also provide a porting guide which will explain
easily how to port &GStreamer;-0.8 applications to &GStreamer;-0.9.
&CHECKLIST;
&PORTING;
&INTEGRATION;
&LICENSING;
&WIN32;
"ES;