GStreamer's development framework makes it possible to write any type of streaming multimedia application. The GStreamer framework is designed to make it easy to write applications that handle either audio or video or both. The pipeline design is made to have no extra overhead above what the applied filters induce. This makes GStreamer a good framework for designing even high-end audio applications which puts high demands on latency.
One of the the most obvious uses of GStreamer is using it to build a media player. GStreamer already includes components for building a media player that can support a very wide variety of formats, including MP3, Ogg Vorbis, MPEG1, MPEG2, AVI, Quicktime, mod and so on. GStreamer, however, is much more than just another media player. Its main advantages are that the pluggable components can be mixed and matched into arbitrary pipelines so that it's possible to write a full-fledged video or audio editing application.
The framework is based on plugins that will provide the various codec and other functionality. The plugins can be connected and arranged in a pipeline. This pipeline defines the flow of the data. Pipelines can also be edited with a GUI editor and saved as XML so that pipeline libraries can be made with a minimum of effort.
The GStreamer core function is to provide a framework for plugins, data flow and media type handling/negotiation. It also provides an API to write applications using the various plugins.
This book is about GStreamer from a developer's point of view; it describes how to write a GStreamer application using the GStreamer libraries and tools. For an explanation about writing plugins, we suggest the Plugin Writers Guide.
The Linux developer who wishes to embed a video clip in their application must use crude hacks to run an external video player. There is no library available that a developer can use to create a custom media player.
If I wanted to convert an MPEG2 video stream into an AVI file, my best option would be to take all of the MPEG2 decoding algorithms out of the player and duplicate them into my own AVI encoder. These algorithms cannot easily be shared accross applications.
Attempts have been made to create libraries for handling various media types. Because they focus on a very specific media type (avifile, libmpeg2, ...), significant work is needed to integrate them due to a lack of a common API. GStreamer allows you to wrap these libraries with a common API, which significantly simplifies integration and reuse.
The lack of a unified plugin mechanism also seriously hinders the creation of binary only codecs. No company is willing to port their code to all the different plugin mechanisms.
While GStreamer also uses it own plugin system it offers a very rich framework for the plugin developper and ensures the plugin can be used in a wide range of applications, transparently interacting with other plugins. The Framework that GStreamer provides for the plugins is flexible enough to host even the most demanding plugins.
No provisions have been made for emerging technologies such as the GNOME object embedding using Bonobo.
The GStreamer cores does not use network transparent technologies at the lowest level as it only adds overhead for the local case. That said, it shouldn't be hard to create a wrapper around the core components.
We must clear the road for commercially backed codecs and multimedia applications so that Linux can become an option for doing multimedia.