DSDPlus Can I read an FMPP-recorded IQ file with something useful?

[AM909]

I recorded a ~3.9 GB, .IQ format, baseband file from FMPP v1.18 by pressing "R" while it was running.

Trying to play it back with the new FMP24 v2.75 in the new DSDPlus v2.347 release with FMP24 < 2021-09-23@185600.IQ, it tells me "Input is not an FMP24 I/Q recording". FWIW, I also tried to read it with FMPP (which has not been updated so is not supposed to support it), and got a 0xC0000094 exception.

How does the format differ between the two?

 

[slicerwizard]

FMP24 and FMPP work with SDRs that have different data sizes (8 bit vs 12 bit) and different sampling rates. I doubt that one would be able to correctly process a recording from the other one. As far as format differences, I'd expect FMP24 recordings to be two bytes per I/Q sample, while FMPP recordings would be three or four bytes per I/Q sample. The size of a timed recording should reveal which it is.