GPAC Introduction

Current version: 2.1-DEV

Latest Release: 2.0

GPAC is an open-source multimedia framework focused on modularity and standards compliance. GPAC provides tools to process, inspect, package, stream, playback and interact with media content. Such content can be any combination of audio, video, subtitles, metadata, scalable graphics, encrypted media, 2D/3D graphics and ECMAScript. GPAC is best-known for its wide MP4/ISOBMFF capabilities and is popular among video enthusiasts, academic researchers, standardization bodies, and professional broadcasters.

For more information, visit GPAC website

GPAC is distributed under the LGPL v2.1 or later, and is also available, for most of it, under a commercial license.

Please ! cite ! our work in your research:

• "GPAC Filters" (https://doi.org/10.1145/3339825.3394929) for recent versions (0.9 or above)
• "GPAC: open source multimedia framework" (https://doi.org/10.1145/1291233.1291452) for older versions.

Features

GPAC can process, analyse, package, stream, encode, decode and playback a wide variety of contents. Selected feature list:

• Audio: MPEG audio (mp1/2/3, aac), AC3, E-AC3, Opus, FLAC, …
• Video: MPEG 1 / 2 / 4 (H264/AVC) / H (HEVC), VVC, AV1, VP9, Theora, ...
• Subtitles: WebVTT, TTML (full, EBU-TTD, …), 3GPP/Apple Timed Text, …
• Encryption: CENC, PIFF, ISMA, OMA, ...
• Containers: MP4/fMP4/CMAF/Quicktime MOV/ProRes MOV, AVI, MPG, OGG, MKV, ...
• Streaming: MPEG-2 Transport Stream, RTP, RTSP, HTTP, Apple HLS, MPEG-DASH, ATSC 3.0 ROUTE, ...
• Supported IOs: local files, pipes, UDP/TCP, HTTP(S), custom IO
• Presentation formats: MPEG-4 BIFS, SVG Tiny 1.2, VRML/X3D
• JS scripting through QuickJS for both SVG/BIFS/VRML and extending GPAC framework tools
• 3D support (360 videos, WebGL JS filters…)
• Inputs: microphone, camera, desktop grabbing
• Highly configurable media processing pipeline
• Python and NodeJS bindings

Features are encapsulated in processing modules called filters:

• to get the full list of available features, you can run the command line gpac -h filters or check filters' wiki.
• to get the full list of playback features, check the dedicated wiki page.

Tools

MP4Box

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.

gpac

GPAC includes a filter engine in charge of stream management and used by most applications in GPAC - read this post for more discussion on how this impacts MP4Box. 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.

Getting started

Download

Stable and nightly builds installers for Windows, Linux, OSX, Android, iOS are available on gpac.io.

If you want to compile GPAC yourself, please follow the instructions in the build section of our wiki.

Documentation

The general GPAC framework documentation is available on wiki.gpac.io, including HowTos.

GPAC tools are mostly wrappers around an underlying library called libgpac which can easily be embedded in your projects. The libgpac developer documentation is available at doxygen.gpac.io, including documentation of JS APIs, Python APIs and NodeJS APIs.

Testing

GPAC has a test suite exercising most features of the framework. The test suite is in a separate repository https://github.com/gpac/testsuite/, 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, read this page and check the testsuite readme.

Per-commit build and tests results are available.

Support, ongoing tasks and bugs

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

Contributing

A complex project like GPAC wouldn’t exist and persist without the support of its community. Please contribute: a nice message, supporting us in our communication, reporting issues when you see them… any gesture, even the smallest ones, counts.

If you want to contribute to GPAC, you can find ideas at GSoC page or look for a good first issue. In any doubt please feel free to contact us.

Team

GPAC is brought to you by an experienced team of developers with a wide track-record on media processing.

The project is mainly developed in the MultiMedia group of Telecom Paris with the help of many great contributors.

GPAC has a peculiar story: started as a startup in NYC, GPAC gained traction from research and a nascent multimedia community as it was open-sourced in 2003. Since then we have never stopped transforming GPAC into a useful and up-to-date project, with many industrial R&D collaborations and a community of tens of thousands of users. This makes GPAC one of the few open-source multimedia projects that gathers so much diversity.

Roadmap

Users are encouraged to use the latest tag or the master branch.

The v0.8.X release (the last one using the legacy architecture) is officially deprecated.

V2.X

Targets:

• drop MP4Client/Osmo4 and GF_Terminal API
• User authentication for HTTP and RTSP servers
• DASH event support
• Web integration (emscripten, Remotery UI)
• Better TTML2 / SMPTE ST 2052-1 support
• configure buffer level per filter
• GUI cleanup ?
• deprecate :filemode in ROUTE
• support ClearKey Content Protection (CCP)
• FFMPEG subtitle support