GPAC Project on Advanced Content (GPAC, a recursive acronym) is an open-source multimedia framework focused on modularity and standards compliance. GPAC was created as an implementation of the MPEG-4 Systems standard written in ANSI C and later extended in Streaming Media. GPAC provides tools to process, inspect, package, stream, media playback and interact with media content. Such content can be any combination of audio, video, subtitles, metadata, encrypted media, rendering and ECMAScript. GPAC provides three sets of tools based on a core library called libgpac: 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, MacOS X, iOS, Android, and many other systems. GPAC is best known for its wide MP4/ISOBMFF capabilities and is popular among video enthusiasts, academic researchers, standardization bodies, and professional broadcasters.

History and standards

GPAC was founded in New York City in 1999 as a company called AviPix. In 2003, it became open-source, with the initial goal of developing from scratch, in ANSI C, clean software compliant with the MPEG-4 Systems architecture standard, as a small and flexible alternative to the MPEG-4 reference software. In parallel, as MPEG-4 was intended to compete with Macromedia Flash, GPAC evolved to support other standards such as X3D, W3C SVG Tiny 1.2, and OMA/3GPP/ISMA and eventually MPEG-DASH. The MPEG-DASH feature can be used to reconstruct .mp4 files from videos streamed and cached in this format (e.g., YouTube). Various research projects used or use GPAC. In 2019 the GPAC team explained the code has undergone a massive re-architecture called Filters with release 0.9 while release 0.8 is the last release of the legacy architecture with an extended 18-months support. The front-end applications remain unchanged, making the transition seamless. The underlying filters build a dynamic modular dataflow pipeline. In 2020 GPAC 1.0 was released. The Website was split into a wiki documentation, a doxygen API documentation, a buildbot and GitHub actions, a testbot with a high coverage. The new gpac application has been used as a FFmpeg on steroids offering additional speed, features, ease of use. Since 2013, GPAC Licensing has offered business support and closed-source licenses. In 2022 Netflix announced using GPAC for their worldwide content operations including the Netflix service, studio content, and merchandising material.

Multimedia content features

Packaging

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. Current supported features are:

Playing

GPAC supports many protocols and standards, among which:

Streaming

As of version 0.4.5, GPAC has some experimental server-side and streaming tools:

Contributors

The project is hosted at Télécom Paris, a leading French engineering school. Current main contributors of GPAC are: Other (current or past) contributors are: Additionally, GPAC is used at Télécom Paris for pedagogical purposes. Students regularly participate in the development of the project.