Function JxlEncoderSetParallelRunner 

pub unsafe extern "C-unwind" fn JxlEncoderSetParallelRunner(
    enc: *mut JxlEncoder,
    parallel_runner: JxlParallelRunner,
    parallel_runner_opaque: *mut c_void,
) -> JxlEncoderStatus

Set the parallel runner for multithreading. May only be set before starting encoding.

Parameters

• enc: Encoder object.
• parallel_runner: Function pointer to runner for multithreading. It may be NULL to use the default, single-threaded, runner. A multithreaded runner should be set to reach fast performance.
• parallel_runner_opaque: Opaque pointer for parallel_runner.

Returns

• JxlEncoderStatus::Success if the runner was set.
• JxlEncoderStatus::Error otherwise (the previous runner remains set).