GPAC Project on Advanced Content (GPAC, a recursive acronym) is an implementation of the MPEG-4 Systems standard written in ANSI C. GPAC provides tools for media playback, vector graphics and 3D rendering, MPEG-4 authoring and distribution.[5]
GPAC provides three sets of tools based on a core library called libgpac:
A multimedia player, cross-platform command-line based MP4Client or with a GUI Osmo4
A multimedia packager, MP4Box
Some server tools, around multiplexing and streaming (under development).
GPAC is cross-platform. It is written in (almost 100% ANSI) C for portability reasons, attempting to keep the memory footprint as low as possible. It is currently running under Windows, Linux, Solaris, Windows CE (SmartPhone, PocketPC 2002/2003), iOS, Android, Embedded Linux (familiar 8, GPE) and recent Symbian OS systems.
The project is intended for a wide audience ranging from end-users or content creators with development skills who want to experiment the new standards for interactive technologies or want to convert files for mobile devices, to developers who need players and/or server for multimedia streaming applications.
GPAC was founded in New York City in 1999.[6] In 2003, it became an open-source project, with the initial goal of developing from scratch, in ANSI C, clean software compliant with the MPEG-4 Systems standard, as a small and flexible alternative to the MPEG-4 reference software.[3]
In parallel, the project has evolved and now supports many other multimedia standards, with support for X3D, W3CSVG Tiny 1.2, and OMA/3GPP/ISMA and MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) features. 3D support is available on embedded platforms through OpenGL-ES.[citation needed] The MPEG-DASH feature can be used to reconstruct .mp4 files from videos streamed and cached in this format (e.g., YouTube).[7] Various research projects used or use GPAC.[8]
Since 2013, GPAC Licensing has offered business support and closed-source licenses.[9]
GPAC features encoders and multiplexers, publishing and content distribution tools for MP4 files and many tools for scene descriptions (BIFS/VRML/X3D converters, SWF/BIFS, SVG/BIFS, etc....). MP4Box provides all these tools in a single command-line application, albeit with extremely arcane syntax. Current supported features are:[10]
MP4/3GP Conversion from MP3, AVI, MPEG-2 TS, MPEG-PS, AAC, H263, H264, AMR, and many others,
^Sofer, Nir (2013). "VideoCacheView". NirSoft.net. Retrieved 2014-01-28. uses MP4Box installed as a part of GPAC package to convert the MPEG-DASH streams into a valid mp4