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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.

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 c2pa_cpp in Your Application​

The recommended way to use this library in your own CMake project is with FetchContent:

include(FetchContent)

FetchContent_Declare(
    c2pa_cpp
    GIT_REPOSITORY https://github.com/contentauth/c2pa-c.git
    GIT_TAG main  # Or use a specific release tag
)
FetchContent_MakeAvailable(c2pa_cpp)

add_executable(myapp main.cpp)
target_link_libraries(myapp PRIVATE c2pa_cpp)

This will automatically fetch, build, and link the c2pa_cpp library and its dependencies.

Note:
This project uses pre-built dynamic libraries from the c2pa-rs repository. It should select the correct library for your platform. If your platform is not supported, you can build your own library using the c2pa_rs repo.

Example Usage​

See the examples/ directory for sample applications that demonstrate how to use the library in practice.

Development​

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

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 build 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.