Re: [Discuss-gnuradio] CVSD encoder -- how to use output?

[Johnathan Corgan]

Eric R Menendez wrote:

> We have been attempting to use GNU Radio to build a transmitter that 
> will encode voice via CVSD, and then transmit via FSK. We have been 
> using the cvsd_encode block to encode the voice samples via CVSD. 
> However, the documentation for this block says that it groups the 
> output bits together into short int samples. How can we extract each 
> bit from the short ints for modulation and transmission?

To convert between the packed and unpacked formats that block uses, use
  the below with 'bits_per_chunk' set to 1.

gr.packed_to_unpacked_ss(bits_per_chunk)
gr.unpacked_to_packed_ss(bits_per_chunk)

These will accept and output short integer item streams.

Note: the gr-cvsd-vocoder component is somewhat buggy and will not be
included in the 3.1 stable branch (well, it might get added back when it
gets fixed on the trunk.)

-- 
Johnathan Corgan
Corgan Enterprises LLC
http://corganenterprises.com