Re: [Discuss-gnuradio] Question about Benchmark_rx.py file code

[Tom Rondeau]

Eric Blossom wrote:
> On Wed, Mar 19, 2008 at 06:02:17PM -0400, address@hidden wrote:
>   
> > The application occasionally crashes on line 66 in the benchmark
> > file, the line is "(pktno,) = struct.unpack('!H', payload[0:2])".? 
> > The error I get is that struct.unpack should be passed a string of
> > at least size 2
> >     
>
> That means that the code is being handed a string of length < 2 bytes.
>   

Not getting the bug after your changes was probably coincidental. I've 
seen this happen on occasion when a packet is receive erroneously and 
the header is corrupted. The framer state machine looks for the repeated 
packet length after correlating with the access code. What's probably 
happening is the header is being read in as double 0's, so it passes on 
a packet of length zero. When unpacking, Python is throwing an exception.

The right thing to do here is catch the exception and mark it as a 
missed packet.

Tom