Re: [Discuss-gnuradio] extract timestamp data

[Eric Blossom]

On Thu, Mar 12, 2009 at 09:51:18AM -0500, Douglas Geiger wrote:
> Cocuzzo, Daniel C. wrote:
> > I'm also wondering about how to extract ethernet packet information,
> > such as timestamp. If anyone has any pointers to reference materials it
> > would be greatly appreciated.
> > 
> > Thanks,
> > Dan
> > 
> > 
> 
>  The easiest way (depending on what you are doing with the timestamps)
> is probably by dealing with the low-level libusrp2, and writing a custom
> copy handler (look at rx_streaming_samples.cc in usrp2/host/apps). The
> metadata structure (in usrp2/metadata.h) provides the timestamp from the
> fpga.

Yes, this the best way to currently get at the timestamp.

>  I'm playing around right now with creating a custom source block that
> has access to the timestamps (i.e. the copy handler passes it from the
> low-level library into the source block - but not to the rest of the
> flowgraph). I'm only interested in it as far as providing aligned
> samples from two USRP2 (like usrp_multi does for the USRP1). Depending
> on what you need the timestamps for, that may be the way to go.
>  Doug

I'll explain in another message what our intermediate range plans are
for dealing with this.

Eric