Re: [Discuss-gnuradio] Hier signal processing block in Python

[Josh Blum]

On 01/24/2013 10:20 AM, Nemanja Savic wrote:
> Hi all,
> 
> Can somebody explain me a bit the difference between blocks written in
> python in the way presented on the website and blocks like packet decoder,
> packet encoder, gfsk modulator, etc. The latter blocks are written also in
> Python, but they are different than the previous. Particularly I don't
> understand why there are also thread classes stick to the blocks from the
> second group.

Those old blocks are just hier blocks with some processing blocks from
gnuradio, where the python interface part is outside of the scheduler,
really just a python thread polling a message queue. The interface is a
python function call or something.

So, there are APIs to create blocks in python that actually use the
scheduler. For example, here is one that does the pkt framer/correlate
but presents a message interface. This block has inputs and outputs that
can be connected in a gnuradio flow graph.

https://github.com/guruofquality/grextras/blob/master/python/packet_framer.py

Then you can do cool things like this:
https://github.com/jmalsbury/pre-cog/wiki

> And the most important thing is I would like to know how to make such block
> out of tree.

Most of the feature above is in gnuradio master branch, but I dont think
there is a doc, so you will have to interpolate from this:

https://github.com/guruofquality/grextras/wiki/Blocks-Coding-Guide

-josh