Function moq_encode_video_demand 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn moq_encode_video_demand(
    producer: u32,
    on_demand: moq_status_callback,
    user_data: *mut c_void,
) -> i32

Watch whether the encoded video track has subscribers, so the camera and encoder run only while someone watches. See crate::moq_publish_media_demand for the callback contract.

Returns a non-zero watcher handle on success, or a negative code on failure.

Safety

• on_demand must be non-NULL.
• The caller must keep user_data valid until the terminal (<= 0) on_demand callback.