Support for SDRplay API version 3.15

[fventuri]

I saw that the current version of 'acarsdec' only supports the old SDRplay API (version 2.X), so I rewrote 'sdrplay.c' to support the latest SDRplay API (version 3.15).

I also added a few more options in the SDRplay case to allow to change the sample rate, the IF bandwidth, frequency correction in PPM, and to enable or disable bias-T and the notch filters for BC and DAB that are built in the SDRplay RSP hardware.

Thanks,
Franco

[f00b4r0]

Hi, thanks for the submission this is a welcome addition. However it's really big. Can you split that huge commit into individual atomic changes? e.g. introducing the V3 API, then adding extra features as separate commits so as to make it easier to review?

Also I'm not sure what's the point of allowing to manually set the sample rate, it's not done for any of the other SDR backends and it adds unnecessary complexity to the code, I'm inclined to NAK that change. Stick to setting the multiplier please. Same with the IF bandwidth, it should be internally computed as is done for RTL and Soapy. Finally please don't unnecessarily rename existing variables (especially to only change character case, I'm talking about GRdB here), it adds noise to the changeset review. Thanks!

[fventuri]

Thanks for the quick reply.
These days I have family visiting, and I'll answer you back after the holidays.

Franco

[f00b4r0]

@fventuri ping? :)

[fventuri]

My apologies Thibaut!
I haven't forgotten about you; I have been so busy with my regular job during the last month that I haven't had much time for the SDR hobby (as a matter of fact I had to work up to few minutes ago).

Hopefully I'll get some time soon, and I'll be able to work on this merge request.

Franco