Re: [Discuss-gnuradio] INFO: Detected an invalid packet at item INFO: Parser returned #f

[Bastian Bloessl]

Hi,

On 01/29/2015 03:13 PM, zs wrote:
> Can you tell me,for general,in which circumstance,the packet header maybe 
> corrupt?

This is very hard to tell since I don't know what you are doing. I guess 
you use a header_formatter in your flow graph and (for whatever reason) 
its header_parse method returns false.

For example with the default header it looks like this happens if the 
CRC is not correct

https://github.com/gnuradio/gnuradio/blob/master/gr-digital/lib/packet_header_default.cc#L132


> At 2015-01-29 20:44:13, "Bastian Bloessl" <address@hidden> wrote:
> > Hi,
> >
> > On 01/29/2015 01:03 PM, zs wrote:
> > > Detected an invalid packet at item INFO: Parser returned #f".
> > > The answer may be "RF settings are distorting your signal" or others.I
> > > want to ask a question.Which block in gnuradio give us this hint.Where
> > > is the source code of the block?And have someone can help me to explain
> > > this problem more details?Why will have this error/warning?
> >
> >
> > ~/src/gnuradio >> ack-grep -C 3 "an invalid packet"
> > gr-digital/lib/packet_headerparser_b_impl.cc
> > 80-      );
> > 81-
> > 82-      if (!d_header_formatter->header_parser(in, tags)) {
> > 83:     GR_LOG_INFO(d_logger, boost::format("Detected an invalid packet at
> > item %1%") % nitems_read(0));
> > 84-     message_port_pub(msg_port_id, pmt::PMT_F);
> > 85-      } else {
> > 86-     pmt::pmt_t dict(pmt::make_dict());
> >
> >
> > I guess your packet header is corrupt.
> >
> > Best,
> > Bastian