If I had to guess someone has probably already worked out the problem and hasn’t put it out there or it’s out there and not prominently displayed. Those rtlsdr dongle really are (were?) a boon to the advancement of SDR. I come across many projects written just for those devices*. It wouldn’t surprise me to learn the solution’s there or very close. Sometimes github searches turn up interesting things. 
[details=*]If only there was an SDR API already in place then all that rtlsdr dongle code would have been usable with other hardware. See
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