[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss-gnuradio] gr_io_signature question

From: Garrett Mcgrath
Subject: [Discuss-gnuradio] gr_io_signature question
Date: Wed, 3 May 2006 00:05:24 -0400

Ok I’ve decided on somewhat of a revisit of my code.  Taking Eric’s advice I’m going to reimplement the code in a more flowgraph based behavior.  After a vector is brought into the system by the MPI (my UDP interface system) some values will be stripped and the pay load will be passed to a first code block that converts the values from an array of U8’s to an array of unsigned shorts that represent the physical bit value (each U8 will have 8 values representing their binary equivalents.).  This will then be parsed into 2 streams (broken at the midpoint of the array into 2 separate streams) and passed out to the encoding block.  This Aloumoti encoder will then use a bit from row 0 and 1 from row 1 and convert them into a 2X2 matrix and pass this out the other end (so I’m assuming a 1:2 or 2:4 interpolation is needed here).  My question is how to utilize ‘gr_io_signature’ in the class derivation to create the 2 output streams, how to return on these 2 steams and then access them on the other end.


I know the python should look something like


#get values from UDP here


MPI_SRC=gr.vector_source(src_data) #the stripped vector









fg.connect((ALOUMOTI_ENCODER,0), TX0PAYLOAD)#these are sink currently so I can check the behavior of my flow graph system.



at least this is the impression I get from the documentation.


However the aloumoti needs these 2 streams in combination to create the output streams, how (in c) do I specify that there are 2 inputs and then proceed to access those inputs in the C system?  I’m already aware it will in some way involve the min_in, min_out, etc. variables and their use in generating an IO signature.


Is it involved in the declaration of the in and out variables at the beginning of the ‘work’ function:

Specifically do I use something akin to:

const float *in0= (const float *) input_items[0];

const float *in1= (const float *) input_items[1];


Any help would be greatly appreciated.


-Garrett McGrath


reply via email to

[Prev in Thread] Current Thread [Next in Thread]