Question about ZeroMQ Sub source

I’ve got a question relating to the zmq sub source.
I’ve got a flowgraph that has rtlsdr -> pub sink

In another graph, I decode FM radio using WBFM receive.
I noticed that it sounds horrible and choppy (sped up).
I looked in the code of the sub source, and saw this

        // Copy to output buffer and return
        if (msg.size() >= d_itemsize*noutput_items)
            memcpy(out, (void *), 

return noutput_items;
} else
memcpy(out, (void *), msg.size());
return msg.size() / (d_itemsize);

Does this mean that if the message size is greater then the number of
requested by scheduler * item size (e.g. complex = 8), the rest of the
message is simply dropped?

This is probably the reason for the choppy audio. How can a situation
this be avoided?

Setting max number of output items in both graphs seems to help this.

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I tried it but it’s still very choppy.

I’m not 100% on the scheduler, but if the downstream graph requests 4096
items, and the zmq message size is 8192 items, wouldn’t this result in
choppy audio?


On Sun, Aug 31, 2014 at 3:56 AM, Johnathan C.
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