Re: [Discuss-gnuradio] Digital TV with USRP and GNU Radio

[Andy Walls]

On Wed, 2016-01-06 at 12:00 -0500, address@hidden
wrote:


> On Wed, Jan 6, 2016 at 11:09 AM, Richard Bell
> <address@hidden>
> wrote:
> 
> > Does anyone know of a good tutorial that shows how to receive and
> display
> > TV on Ubuntu using a USRP and GNU Radio? I'm interested.
> >
> > Rich
> >
> 
> 
> Rich,
> 
> I'm not sure anyone's written it up, but there are examples in
> gr-dtv/examples. I just looked, and we've neglected to add the files
> to the
> CMakeLists.txt file to install these properly. Regardless, if you have
> the
> source code, look at uhd_atsc_capture.grc and file_atsc_rx.grc. If you
> have
> a powerful enough machine, you can also try uhd_rx_atsc.grc directly.
> 
> I think it'd be great if someone wrote a tutorial showing to how use
> these.
> 
> Tom

Well assuming, you have all the CPU you need:

Start with the simple thing to do: save to a file and then play the
file:
a. Use uhd_rx_atsc.grc to capture a channel as an MPEG TS to a file
named mpeg.ts
b. $ cat mpeg.ts | mplayer -


Then, as a better thing to do: spit out the MPEG TS on a local socket
and play it locally from the socket:
a. Modify uhd_rx_atsc.grc to capture a channel as an MPEG TS and send it
out a TCP Sink or UDP Sink block.
b. $ socat TCP4:127.0.0.1:1234 - | mplayer -

(socat arguments may need tweaking)
socat (a better netcat) and its documentation are available here, if not
packaged by your distro:
http://www.dest-unreach.org/socat/


And then as an even better thing to do: spit out the MPEG TS on a local
socket and then let VLC handle playing locally or streaming over the
network:
a. Modify uhd_rx_atsc.grc to capture a channel as an MPEG TS and send it
out a TCP Sink or UDP Sink block.
b. $ vlc tcp://127.0.0.1:1234 

(vlc arguments may need tweaking, I don't know if that actually works)
VLC can act as a streaming server as well as a decoder/viewer, so you
can use it to stream to other VLC clients on other machines using RTSP
or other multimedia protocols.

Regards,
Andy