The VCA SDK is a separately built library which allows users to create their own camera connectors and use them with VCA. The VCA Drivers repository contains a pre-built version of this SDK with the necessary header files under the "sdk" folder. Every custom camera connector package must contain the libVCA-SDK.so and the custom camera connector library must link to this .so file.
By default, the custom camera connector package creation and linkage is handled by CMake configuration and build scripts. More information about this can be found in the "Creating and using a camera connector" section.