Function initialize_mf

rustcv-backend-msmf/src/device.rs:48–71

Initializes the Media Foundation and COM subsystem This function performs one-time initialization of the Windows Media Foundation and COM runtime. It uses reference counting to ensure proper lifecycle management. Multiple calls are safe; only the first call performs actual initialization. Uses compare_exchange for efficient lock-free initialization.

()

///
/// Uses compare_exchange for efficient lock-free initialization.
pub fn initialize_mf() -> Result<()> {
    if INITIALIZED
        .compare_exchange(false, true, Ordering::SeqCst, Ordering::Relaxed)
        .is_ok()
    {
        // We won the race to initialize
        unsafe {
            if let Err(e) = CoInitializeEx(None, COINIT_APARTMENTTHREADED).ok() {
                INITIALIZED.store(false, Ordering::Release);
                return Err(CameraError::Io(std::io::Error::other(e.to_string())));
            }

            if let Err(e) = MFStartup(MF_API_VERSION, MFSTARTUP_NOSOCKET) {
                // Clean up COM if MF startup fails
                CoUninitialize();
                INITIALIZED.store(false, Ordering::Release);
                return Err(CameraError::Io(std::io::Error::other(e.to_string())));
            }
        }
    }
    // Increment reference count (use Release for synchronization with shutdown)
    CAMERA_REFCNT.fetch_add(1, Ordering::Release);
    Ok(())
}

/// Shuts down the Media Foundation subsystem
///