C2PA C++ library

The c2pa-c repository implements C++ APIs that:

• Read and validate C2PA data from media files in supported formats.
• Add signed manifests to media files in supported formats.

Although this library works for plain C applications, the documentation assumes you're using C++, since that's most common for modern applications.

WARNING: This is a prerelease version of this library. There may be bugs and unimplemented features, and the API is subject to change.

For the best experience, read the docs on the CAI Open Source SDK documentation website. If you want to view the documentation in GitHub, see:

• Using the C++ library
• Supported formats

Installation

CMake setup

Build the project using CMake and FetchContent like this:

FetchContent_Declare(
    c2pa_cpp
    GIT_REPOSITORY https://github.com/contentauth/c2pa-c.git
    GIT_TAG gpeacock/cmake_work`
)
FetchContent_MakeAvailable(c2pa_cpp)

And then add "${c2pa_cpp_SOURCE_DIR}/include" to your include path.

Development

This project has been tested on macOS and should also work on common Linux distributions.

Prerequisites

If you haven't already done so, install Rust.

Install cbindgen:

cargo install --force cbindgen

You must install the Ninja build system to run the unit tests.

Building

Building the library requires GNU make, which is installed on most macOS systems.

Enter this command to build the C library:

make release

The Makefile has a number of other targets; for example:

• unit-tests to run C++ unit tests
• examples to build and run the C++ examples.
• all to run everything.

Results are saved in the target directory.

Testing

Build the unit tests by entering this make command:

make unit-test

License

This package is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

Note that some components and dependent crates are licensed under different terms; please check the license terms for each crate and component for details.

Contributions and feedback

We welcome contributions to this project. For information on contributing, providing feedback, and about ongoing work, see Contributing.