M-block <--> GR block integration

Hello all,

I’ve got an application that needs the new inband timestamp capability,
and could really use some of the stuff already provided as GR blocks.
So what I need is m-block support for GR flowgraphs. Is anybody
currently working on this? If so I’d be happy to help out, and if not,
I’d like to see if it makes sense for me to tackle this myself and
contribute it back to gnuradio.

I’d be happy for any advice, information, etc. that’s not available on
the web. I noticed that George said he could email the latest RBF, so
I’m going to ping him about that separately.


Hi Hugh,

So, I opened up a can of worms from that e-mail :slight_smile:

This functionality is actually scheduled to be worked on by Eric in
about two weeks. He has been holding off on doing this because of a
performance problem in the m-block that we’re not 100% sure of yet.

In short, the performance problem is significant enough to cripple the
inband code which you want to use for timestamps purposes. The blocks
are basically having trouble keeping up with the USRP which causes
memory issues, overruns, underruns, you name it!

My suggestion would be to wait it out for a couple weeks until the
m-block problem is fixed and we release a stable version of the inband
code. Leo and I are wrapping up the inband code right now, we just
committed one of the last missing pieces of the code today.

Eric probably has a solid idea of how to glue the GR blocks and m-blocks
together since he wrote the code for both blocks and has been thinking
about it since I’ve also been poking him to write the code. So he may
just want to tackle it himself, or if you’re sincerely interested in
helping maybe you can work on it with him. We will probably be
discussing the interface over the list soon which we all could
participate in.

  • George

Since Eric’s going to be working on this pretty soon, I think I’ll take
George’s advice and wait a bit.