public static extern int hackrf_start_rx(IntPtr dev, hackrf_sample_block_cb_fn cb, IntPtr rx_ctx);
public static extern IntPtr hackrf_stop_tx(IntPtr dev, hackrf_sample_block_cb_fn sample_block, IntPtr tx_ctx);
public static extern int hackrf_start_rx(IntPtr dev, hackrf_sample_block_cb_fn cb, IntPtr rx_ctx);
private static extern IntPtr hackrf_start_tx(IntPtr dev, hackrf_sample_block_cb_fn sample_block, IntPtr tx_ctx);