Page 1 of 1

rfchanged etc. semantics

Posted: Tue Jan 10, 2017 2:27 pm
by jpsa
Hi... I'm trying to work out what the semantics are of the grChanged, rfChanged and fsChanged parameters to the mir_sdr_StreamCallback_t stream callback. I have a couple of questions which don't seem to be answered by the documentation...
  • If, say, rfChanged is non-zero, does that indicate that the IQ data passed to this callback does not yet reflect a new frequency setting, or does it indicate that it's the first call with data which does incorporate that change? Or does it mean something else entirely?
  • The documentation talks about bits within those values referring to the 1st, 2nd, 3rd & 4th packets. What do these packet numbers mean in the context of this callback?

Re: rfchanged etc. semantics

Posted: Wed Jan 11, 2017 5:36 pm
by mikael
xxChanged indicates that the new value is in effect for the data delivered by this call. Using syncUpdate, you can calculate the exact sample this occurred, elsewise you only know it occurred somewhere within numSamples.

The driver aggregates four low level packets for each stream callback. The bits pinpoints exactly in which packet the change took effect.

Re: rfchanged etc. semantics

Posted: Wed Jan 11, 2017 8:16 pm
by jpsa
Thank you!