# my struct is defined in SDR.h

struct rtlsdr_dev {
	libusb_context *ctx;
	struct libusb_device_handle *devh;
	uint32_t xfer_buf_num;
	uint32_t xfer_buf_len;
	struct libusb_transfer **xfer;
	unsigned char **xfer_buf;
	rtlsdr_read_async_cb_t cb;
	void *cb_ctx;
	enum rtlsdr_async_status async_status;
	int async_cancel;
	int use_zerocopy;
	/* rtl demod context */
	uint32_t rate; /* Hz */
	uint32_t rtl_xtal; /* Hz */
	int fir[FIR_LEN];
	int direct_sampling;
	/* tuner context */
	enum rtlsdr_tuner tuner_type;
	rtlsdr_tuner_iface_t *tuner;
	uint32_t tun_xtal; /* Hz */
	uint32_t freq; /* Hz */
	uint32_t bw;
	uint32_t offs_freq; /* Hz */
	int corr; /* ppm */
	int gain; /* tenth dB */
	struct e4k_state e4k_s;
	struct r82xx_config r82xx_c;
	struct r82xx_priv r82xx_p;
	/* status */
	int dev_lost;
	int driver_active;
	unsigned int xfer_errors;
};