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110 lines
3 KiB
Text
110 lines
3 KiB
Text
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<chapter id="cha-goals">
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<title>Goals</title>
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<para>
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GStreamer was designed to provide a solution to the current Linux media
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problems.
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</para>
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<sect1 id="sec-goals-design">
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<title>The design goals</title>
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<para>
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We descibe what we try to achieve with GStreamer.
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</para>
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<sect2 id="sec-goals-clean">
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<title>Clean and powerfull</title>
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<para>
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GStreamer wants to provide a clean interface to:
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</para>
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<itemizedlist>
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<listitem>
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<para>
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The application programmer who wants to build a media pipeline.
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</para>
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</listitem>
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<listitem>
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<para>
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The plugin programmer.
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</para>
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</listitem>
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</itemizedlist>
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</sect2>
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<sect2 id="sec-goals-object">
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<title>Object oriented</title>
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<para>
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Adhere as much as possible to the GTK+ object model. A programmer familiar
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with GTK+ will be confortable with GStreamer.
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</para>
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<para>
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GStreamer uses the mechanisems of signals and object arguments.
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</para>
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</sect2>
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<sect2 id="sec-goals-extensible">
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<title>Extensible</title>
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<para>
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All GStreamer Objects can be extended using the GTK+ inheritance methods.
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</para>
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<para>
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All plugins are loaded dynamically and can be extended and upgraded
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independently.
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</para>
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</sect2>
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<sect2 id="sec-goals-binary">
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<title>Allow binary only plugins</title>
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<para>
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plugins are shared libraries that are loaded at runtime. since all the
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properties of the plugin can be set using the GtkObject arguments, there
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is no need to have any header files installed for the plugins.
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</para>
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</sect2>
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<sect2 id="sec-goals-performance">
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<title>High performance</title>
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<para>
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High performance is obtained by:
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</para>
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<itemizedlist>
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<listitem>
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<para>
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Using glib g_mem_chunk where possible to minimize dynamic memory
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allocation.
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</para>
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</listitem>
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<listitem>
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<para>
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Connections between plugins are extremely light-weight. Data can travel
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the pipeline with minimal overhead.
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</para>
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</listitem>
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<listitem>
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<para>
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Provide a mechanism to directly work on the target memory. A
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plugin can for example directly write to the X servers shared mem.
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Buffers can also point to arbitrary memory like kernel memory.
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</para>
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</listitem>
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<listitem>
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<para>
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Refcounting and copy on write to minimize the amount of memcpy.
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Subbufers to efficiently split the data in a buffer.
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</para>
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</listitem>
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<listitem>
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<para>
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Pipelines can be constructed using cothreads to minimize the
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threading overhead. Cothreads are a simple user-space method for
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switching between subtasks.
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</para>
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</listitem>
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<listitem>
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<para>
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HW acceleration is possible by writing a specialized plugin.
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</para>
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</listitem>
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</itemizedlist>
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</sect2>
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</sect1>
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</chapter>
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