have *_write_reg() functions pass through the return value

Signed-off-by: Steve Markgraf <steve@steve-m.de>
disable DAGC by default, add control function

This adds rtlsdr_set_agc_mode() to enable/disable it.
Thanks to Leif Asbrink for finding this setting.

Signed-off-by: Steve Markgraf <steve@steve-m.de>
add PIDs for 2 variants of the Terratex NOXON dongle

Signed-off-by: Steve Markgraf <steve@steve-m.de>
apply frequency correction value on the xtal clock directly

by using this approach both, the tuning frequency and the sample rate
should be corrected at the same time.
rtlsdr_set_tuner_if_gain(): enable i2c repeater

Thanks to Stefan Sydow for noticing this bug.

Signed-off-by: Steve Markgraf <steve@steve-m.de>
disable sample rate correction until we find a proper solution
add debug messages to rtlsdr_read/write_array

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: prototype FM demod

Signed-off-by: Steve Markgraf <steve@steve-m.de>
build rtl_fm

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: satisfactory squelch

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: add -E for optional lower edge tuning

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: broken multi freq scanning

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: multithreaded and frequency scanning

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: tweaks for nicer scanning

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: missed a var init

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: crude integer atan2, around 40% faster

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: disabling fast_atan2() for now, too noisy

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: add experimental options

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: use getopt on win32 as well

Signed-off-by: Steve Markgraf <steve@steve-m.de>
rtl_fm: fix typo that caused warning

Signed-off-by: Steve Markgraf <steve@steve-m.de>