mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-15 13:53:19 +00:00
d2c3b2087d
Original commit message from CVS: conversion to docbook-xml. i don't have to ask that this be testing, because not ionly is it perfect, but i'm sure you folks will learn that on your own :-)
131 lines
4 KiB
XML
131 lines
4 KiB
XML
<chapter id="cha-goals">
|
|
<title>Goals</title>
|
|
<para>
|
|
GStreamer was designed to provide a solution to the current Linux media
|
|
problems.
|
|
</para>
|
|
|
|
<sect1 id="sec-goals-design">
|
|
<title>The design goals</title>
|
|
<para>
|
|
We descibe what we try to achieve with GStreamer.
|
|
</para>
|
|
<sect2 id="sec-goals-clean">
|
|
<title>Clean and powerfull</title>
|
|
<para>
|
|
GStreamer wants to provide a clean interface to:
|
|
</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>
|
|
The application programmer who wants to build a media pipeline.
|
|
The programmer can use an extensive set of powerfull tools to create
|
|
media pipelines without writing a single line of code. Performing
|
|
complex media manipulations becomes very easy.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
The plugin programmer. Plugin programmers are provided a clean and
|
|
simple API to create self contained plugins. An extensive debugging
|
|
and tracing mechanism has been integrated. GStreamer also comes with
|
|
an extensive set of real-life plugins that serve as an example too.
|
|
</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
</sect2>
|
|
<sect2 id="sec-goals-object">
|
|
<title>Object oriented</title>
|
|
<para>
|
|
Adhere as much as possible to the glib2.0 object model. A programmer familiar
|
|
with glib2 and GTK+ will be confortable with GStreamer.
|
|
</para>
|
|
<para>
|
|
GStreamer uses the mechanism of signals and object arguments.
|
|
</para>
|
|
<para>
|
|
All objects can be queried at runtime for their various properties and
|
|
capabilities.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="sec-goals-extensible">
|
|
<title>Extensible</title>
|
|
<para>
|
|
All GStreamer Objects can be extended using the glib2 inheritance methods.
|
|
</para>
|
|
<para>
|
|
All plugins are loaded dynamically and can be extended and upgraded
|
|
independently.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="sec-goals-binary">
|
|
<title>Allow binary only plugins</title>
|
|
<para>
|
|
plugins are shared libraries that are loaded at runtime. since all the
|
|
properties of the plugin can be set using the GObject properties, there
|
|
is no need to have any header files installed for the plugins.
|
|
</para>
|
|
<para>
|
|
Special care has been taking into making the plugin completely self
|
|
contained. This is in the operations, specification of the capabilities
|
|
of the plugin and properties.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="sec-goals-performance">
|
|
<title>High performance</title>
|
|
<para>
|
|
High performance is obtained by:
|
|
</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>
|
|
Using glib g_mem_chunk where possible to minimize dynamic memory
|
|
allocation.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Connections between plugins are extremely light-weight. Data can travel
|
|
the pipeline with minimal overhead.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Provide a mechanism to directly work on the target memory. A
|
|
plugin can for example directly write to the X servers shared mem.
|
|
Buffers can also point to arbitrary memory like kernel memory.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Refcounting and copy on write to minimize the amount of memcpy.
|
|
Subbufers to efficiently split the data in a buffer.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Pipelines can be constructed using cothreads to minimize the
|
|
threading overhead. Cothreads are a simple user-space method for
|
|
switching between subtasks.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
HW acceleration is possible by writing a specialized plugin.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Uses a plugin registry with the specifications of the plugins so
|
|
that the plugin loading can be delayed until the plugin is actually
|
|
used.
|
|
</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
</sect2>
|
|
</sect1>
|
|
</chapter>
|