mirror of
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a224ca3afa
Remove mention of the aRTSd and esd sound servers and such.
145 lines
6.5 KiB
Markdown
145 lines
6.5 KiB
Markdown
# General
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## Is GStreamer a media player ?
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No, GStreamer is a development framework for creating applications like
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media players, video editors, streaming media broadcasters and so on.
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That said, very good media players can easily be built on top of GStreamer
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especially when using the high-level APIs we provide such as `GstPlayer` or
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the `playbin` and `playbin3` elements.
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## Why is GStreamer written in C ? Why not C++/Objective-C/... ?
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We like C. Aside from "personal preference", there are a number
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of technical reasons why C is nice in this project:
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- C is extremely portable.
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- C is fast.
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- It is easy to make language bindings for libraries written in C.
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- The GObject object system provided by GLib implements objects in C,
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in a portable, powerful way. This library provides for introspection
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and runtime dynamic typing. It is a full OO system, but without the
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syntactic sugar. If you want sugar, take a look at
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[Vala](http://live.gnome.org/Vala).
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- Use of C integrates nicely with Gtk+ and GNOME. Some people like
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this a lot, but neither Gtk+ nor GNOME are required by GStreamer.
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There are also historical reasons: When GStreamer was started, C++ and
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free and open source C++ compilers were not as stable and mature as they
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are today, and there was the desire to provide a certain degree of
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API and ABI stability.
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So, in closing, we like C. If you don't, that's fine; if you still want
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to help out on GStreamer, we always need more language binding people.
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And if not, don't bother us; we're working :-)
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## What kind of applications have been written in GStreamer?
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GStreamer has been designed from the start to be a general-purpose multimedia
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framework that can be used to write all kinds of multimedia applications.
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There are a huge number of media playback applications of course, but also
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audio and video capture applications that record to file or live stream the
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captured content. Audio CD and DVD backup applications. Media format conversion
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and transcoding tools. Streaming servers, both for small embedded devices where
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resource usage needs to be tightly controlled, and for servers where scalability
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is key. And of course audio and video editing applications.
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For a list of projects, look at the [application
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list](http://gstreamer.freedesktop.org/apps/) on the GStreamer project
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website.
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## Does GStreamer support the format of my media files?
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GStreamer is plugin based and was designed to be extensible from the start,
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so it can pretty much support any media format provided suitable plugins
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are available.
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It features demuxers, parsers and decoders for all common media formats and
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hundreds of uncommon ones. If you have trouble playing back a file please
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first make sure you have all the required plug-ins installed.
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GStreamer aims to support every format imaginable, but that
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doesn't mean the developers have managed to achieve that aim yet. If a
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GStreamer enabled application doesn't play back your files, you can help
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us solve that problem by [filing an enhancement request
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bug](http://bugzilla.gnome.org) for that format. If you have it, please
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provide:
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- links to other players, preferably Open Source and working on Unix
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- links to explanations of the format.
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- ways to obtain mediafiles in that format to test.
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## What are the exact licensing terms for GStreamer and its plugins?
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All of GStreamer, including our own plugin code, is licensed
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under the [GNU LGPL 2.1](http://www.gnu.org/licenses/lgpl-2.1.html)
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license. Some of the libraries we use for some of the plugins are
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however under the GPL, which means that those plugins can not be used by
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a non-GPL-compatible application. Those are few and far between though
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and there are usually non-GPL alternatives available for those GPL libraries.
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As part of the GStreamer source download you find a file called
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LICENSE\_readme in gst-plugins package. That file contains information
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in the exact licensing terms of the libraries we use. As a general rule,
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GStreamer aims at using only LGPL or BSD licensed libraries if available
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and only use GPL or proprietary libraries where no good LGPL or BSD
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alternatives are available.
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You can see the effective license of a plugin as license field in
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`gst-inspect-1.0`. In the future we might have the application enforce a
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stricter policy (much like tainting in the kernel).
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## Is GStreamer a sound server ?
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No, GStreamer is not a soundserver. GStreamer does however have
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plugins supporting most of the major soundservers available today,
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including pulseaudio, Jack and others.
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## Is GStreamer available for platforms other than Linux?
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Yes, GStreamer is a cross-platform multimedia framework that
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works on all major operating systems, including but not limited to
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Linux, Android, iOS, macOS, Windows, and *BSD, and there are official
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SDK binary packages for Android, iOS, macOS and Windows made available
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with every GStreamer release.
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## What is GStreamer's relationship with the GNOME community ?
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GStreamer is an independent project, but we do traditionally have
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a close relationship with the GNOME community. Many of our hackers
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consider themselves also to be members of the GNOME community. GStreamer
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is officially bundled with the GNOME desktop, as lots of GNOME applications
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are using it. This does not exclude use of GStreamer by other communities
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at all, of course.
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## What is GStreamer's relationship with the KDE community ?
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The GStreamer community wants to have as good a relationship as
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possible with KDE, and we hope that someday KDE decides to adopt
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GStreamer as their multimedia platform. There have been contacts
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from time to time between the GStreamer community and KDE and
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GStreamer is used by various KDE and Qt multimedia APIs. Also,
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some of the KDE hackers have created Qt bindings of GStreamer, made a
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simple video player and using it in some audio players (JuK and AmaroK).
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## I'm considering adding GStreamer output to my application...
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That doesn't really make sense. GStreamer is not a sound server,
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so you don't output directly to GStreamer, and it's not an intermediate
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API between audio data and different kinds of audio sinks. It is a
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fundamental design decision to use GStreamer in your application; there are
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no easy ways of somehow 'transfering' data from your app to GStreamer (well,
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there are of course, but they would be reserved for special use cases).
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Instead, your application would have to use or implement a number of GStreamer
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elements, string them together, and tell them to run. In that manner the
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data would all be internal to the GStreamer pipeline.
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That said, it is possible to write a plugin specific to your app that
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can get at the audio or video data.
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