Documentation of the core library of GPAC
libgpac Documentation

README for GPAC version 0.9.0-DEV


GPAC is a multimedia framework oriented towards rich media and distributed under the LGPL license (see COPYING).

GPAC supports many multimedia formats, from simple audiovisual containers (avi, mov, mpg) to complex presentation formats (MPEG-4 Systems, SVG Tiny 1.2, VRML/X3D) and 360 videos. GPAC supports presentation scripting for MPEG4/VRML/X3D through QuickJS javascript engine.

GPAC currently supports local file playback, HTTP progressive download, Adaptive HTTP Streaming (MPEG-DASH, HLS), RTP/RTSP streaming over UDP (unicast or multicast) or TCP, TS demuxing (from file, IP or DVB4Linux), ATSC 3.0 ROUTE sessions, desktop grabbing, camera/microphone inputs and any input format supported by FFmpeg.

For more information, visit the GPAC website

GPAC is being developped at Telecom Paris, in the MultiMedia group, by many great contributors

GPAC includes the following applications built by default:


MP4Box is a multi-purpose MP4 file manipulation for the prompt, featuring media importing and extracting, file inspection, DASH segmentation, RTP hinting, ... See MP4Box -h, man MP4Box or our wiki.


MP4Client is a media player built upon libgpac, featuring a rich media interactive composition engine with MPEG-4 BIFS, SVG, VRML/X3D support. For GPAC configuration instruction, check MP4Client -h , man MP4Client or our wiki.


As of version 0.9.0, GPAC includes a filter engine in charge of stream management and used by most applications in GPAC - check this for more dicussion on how this impacts MP4Box and MP4Client. The gpac application is a direct interface to the filter engine of GPAC, allowing any combinaison of filters not enabled by other applications. See gpac -h, man gpac, man gpac-filters or our wiki for more details.


Ongoing tasks and bugs

Please use github for feature requests and bug reports. When filing a request there, please tag it as feature-request.


Remaining before release

  • [x] move encrypter to filter
  • [x] move ATSC demux to filter
  • [x] move NVDec to filter
  • [x] move MediaCodec to filter
  • [x] move DekTec output to filter
  • [x] move HEVC tile splitter to filter
  • [x] move HEVC tile merger to filter
  • [x] merge AV1
  • [x] merge VP9
  • [x] move iOS client to filters
  • [ ] move Android client to filters
  • [x] rewrite MP42TS to filters or drop it
  • [ ] fixed features disabled during rearchitecture or drop them (FILTER_FIXME macro)
  • [x] add pipe source and sink
  • [x] add tcp source and sink
  • [x] add generic serializer/reader for all events/packets in filter arch
  • [x] add Remotery support
  • [x] filter API documentation
  • [x] add segmentation handling in TS muxer
  • [x] unify vout / WebGL color handling (complete) and compositor GLSL shaders (partial color support)
  • [x] pass all master test suite
  • [x] extend coverage and test suite
  • [x] update doxygen
  • [ ] merge into master



  • [ ] freeze filter API
  • [x] improve filter graph resolver
  • [x] improve filter scheduler
  • [x] add ffmpeg muxer support
  • [x] add ffmpeg avfilter support
  • [ ] add kvazaar/other encoders support?
  • [x] drop SpiderMonkey and move to QuickJS
  • [x] filters scriptable through JS
  • [x] add 2D vector graphics for JS filters
  • [x] add WebGL vector graphics for JS filters
  • [x] JS modules API documentation
  • [ ] improve mp4 demux from pipe
  • [x] support for HTTP output (server and put/post)
  • [x] add TS spliter filter
  • [ ] move input sensors to filter ?
  • [-] split test suite from main repo and handle PRs with attachements

Future Roadmap

  • [ ] filters scriptable through other languages (python) ?


GPAC has a test suite exercicing most features of the framework. As of 0.9.0, the test suite is in a separate repository, but is available as a submodule of the GPAC main repository. To initialize the testsuite submodule, do git submodule update --init.

For more details on the test suite, check the testsuite readme.

Per-commit build and tests results are available.

Compilation and Installation

Please visit the build section of our wiki.

Source code tree

This is a short overview of the gpac source repository.

  • gpac/applications/ various apps of GPAC, including MP4Box, MP4Client, gpac and other players for iOS and Android
  • gpac/bin/ output path of build system
  • gpac/build/ various build systems (MSVC, Android, XCode, ...)
  • gpac/debian/ files for debian packaging
  • gpac/extra_lib/ external lib directory used by different build systems
  • gpac/include/gpac/ all exported files of the lib (high level APIs, full documentation available).
  • gpac/include/gpac/internal/ all development files of the lib (low level access).
  • gpac/include/gpac/modules/ all module APIs defined in GPAC.
  • gpac/packagers/ installer scripts for Windows and OSX
  • gpac/modules/ various modules of GPAC (video and audio output, font engine, sensors, ...)
  • gpac/share/doc doxygen for GPAC
  • gpac/share/doc/man man pages for GPAC
  • gpac/share/gui/ BIFS+SVG based GUI used by client.
  • gpac/share/lang/ Language files (under development) for GPAC options and help
  • gpac/share/scripts/ various JS scripts used by GPAC.
  • gpac/share/shaders/ GLSL shaders used by the compositor.
  • gpac/share/vis/ Remotery web client.
  • gpac/src/bifs/ BInary Format for Scene coding (decoder and encoder) (BIFS tables are with MPEG4Gen application in gpac/applications/generators/MPEG4)
  • gpac/src/compositor/ interactive composition engine for 2D & 3D drawing - handles MPEG-4, X3D/VRML and SVG.
  • gpac/src/crypto/ cryptographic tools (AES 128 CBC and CTR only)
  • gpac/src/evg/ anti-aliased software rasterizer for 2D vector graphics
  • gpac/src/filter_core/ filter engine of GPAC, in charge of filter graph resolution, filter scheduling, packets handling.
  • gpac/src/filters/ filters defined in GPAC. This include encoders, decoders, av output, wrapper for GPAC's compositor, ISOBMF, RTP, M2TS muxers and demuxers, etc ...
  • gpac/src/ietf/ small RTP/RTSP/SDP library, plus media packetizers.
  • gpac/src/isomedia/ ISOBMFF (Iso Base Media File Format), features file reading/writing/editing, precise interleaving, hint track creation and movie fragments (read/write). Includes 3GPP/3GPP2 , AVC/SVC, HEVC/L-HEVC and JPEG2000 support.
  • gpac/src/jsmods/ Various JavaScript modules
  • gpac/src/laser/ MPEG-4 LAsER (Lightweight Application Scene Representation)
  • gpac/src/media_tools/ media tools for authoring: ISMA & 3GPP tools, AV parsers, media importing and exporting, hinting ...
  • gpac/src/odf/ MPEG-4 Object Descriptor Framework: encoding/decoding of all descriptors, OD codec and OCI codec
  • gpac/src/quickjs/ QuickJS javascript engine sources
  • gpac/src/scene_manager/ memory representation of the scene, importers (BT/XMT/SWF/QT), dumpers and encoding
  • gpac/src/scenegraph/ scene Graph API (MPEG4/VRML/X3D/SVG) - BIFS/VRML/X3D nodes are generated using gpac/applications/generators/*
  • gpac/src/terminal/ client application engine. This is a simple wrapper around the filter engine of GPAC.
  • gpac/src/utils/ all generic objects used throughout the lib (list, bitstream, thread, mutex...). The OS specific files are prefixed os_* .
  • gpac/testsuite/ tests suite for GPAC - this is a GIT submodule.

For more information, visit: