setFrameCrypto(encrypt:decrypt:getMaxSize:userData:)

Installs, replaces, or removes frame crypto with C callbacks (the C callback version).

@discardableResult @MainActor func setFrameCrypto(encrypt: FrameEncryptCallback?, decrypt: FrameDecryptCallback?, getMaxSize: FrameGetMaxSizeCallback?, userData: UnsafeMutableRawPointer?) -> Int32

Return Value

The RevueKit result code (0 on success).

Discussion

The callbacks work directly on the SDK’s buffers, so no frame is copied. For most Swift code, setFrameCryptor(_:) is simpler and lets the SDK manage memory.

To install, pass all three callbacks. To remove, pass nil for all three and for userData, or call clearFrameCryptor(). Passing only some of them returns -2 and keeps the current setting.
Call it any time after initialize, including during a call. Before initialize it returns -1 and installs nothing. The last installed version replaces the other one.
The callbacks run synchronously on the SDK’s media threads, and audio and video can run at the same time: make them thread-safe and non-blocking, and do not call SDK APIs from them.

Important
userData is owned by the App, and the SDK never retains or releases it. A media thread may still be using the previous userData when it is replaced or removed, so release a replaced userData only after destroy() returns.