Re: [Discuss-gnuradio] The GSoC project on LDPC codes.

[ikjtel]

Greetings

I was very interested in this project for possible application to the op25 project, since P25 uses several FEC codes
including RS and other block codes.  I've brought up the gr-ldpc library and have a few questions.  Due to the hateful YAhoo mail composer, I'm hesitant to post lengthy emails to the general list with no opportunity for preview prior to hitting SEND, so I'll try breaking up the list of questions into several posts, one per question...

First question: I was getting lots of errors, seg faults, aborts, and other misbehavior from the code, which were traced to an apparent bug in alist.cc, all of which cleared up when I applied the following patch:

--- ../../repo/gr-ldpc/lib/alist.cc     2013-10-18 10:25:47.508781061 -0400
+++ ./alist.cc  2013-11-05 11:21:03.879972116 -0500
@@ -123,7 +123,7 @@
     }
 
     // Parse indices with non zero entries in ith row
-    for (int row = 0; row < N; row++) {
+    for (int row = 0; row < M; row++) {
         std::getline(file, line);
         ss << line;
         for (int entry = 0; entry < num_mlist[row]; entry++) {

Can you confirm, is this really a bug?

Thanks and Best

Max