Hi folks,
So, the decoder now does IMBE decoding (you need to turn it on, its
switched
off by default) and this can be used to get audio in real-time.
I experienced an unexpected surprise in that I discovered output sinks
are
rate-limiting (like the USRP or the file throttle) and now understand
how
this works with the decoder block’s forecast() method. Our block
receives
4800 symbols/s and produces 8000s/s so forecast should return an
estimate of
3/5 of the required output for its input. Trouble is, there is overhead
of
HDU/TDU, a need to synchronize and so on so I am going to make that
factor
- In the short term I’ve dropped the file throttle because that means
IMBE
decoding works properly but it does screw up the GUI (the flow graph
runs
faster than the GUI blocks would like). As soon as I get some time I’ll
address that but I thought you’d prefer to play just now. If you want
the
old behaviour just comment out the “if 0:” line in the receiver and
leave
IMBE alone.
Steve