[Discuss-gnuradio] ATSC decoding

[Stephen Branch]

Hello everyone,

I am part of Auburn University's Software Defined Radio Senior Design team,

Software being used:
Ubuntu v.9.10 on xfs partition
GNURadio v.3.3 (git)
Xine

Available hardware: USRP1, USRP2, WBX daughterboard, TVRX daughterboard

We followed the instructions in ./gnuradio/gr-atsc/src/python/README to no 
success.

Using the FFT we found 507.25M to have a strong signal.
According to 
http://en.wikipedia.org/wiki/North_American_broadcast_television_frequencies#UHF_band
 this is channel 20.
And according to 
http://www.fcc.gov/fcc-bin/tvq?state=AL&call=&arn=&city=&chan=14&cha2=69&serv=&type=0&facid=&list=2&dist=&dlat2=&mlat2=&slat2=&dlon2=&mlon2=&slon2=&size=9
 this is WCOV from Montgomery, Alabama.
So we do have the correct video carrier frequency, which I assume is the 
frequency we want to record and decode into a video.

Question #1) Is the video carrier the one that carriers the video, or would it 
be the ATSC carrier?

We then used:
./usrp_rx_cfile.py -s -d 10 -g 20 -f 507.25e6 atsc_data_6-4m_complex
./interp_short.py atsc_data_6-4m_complex
./xlate.py
./fpll.py
./btl-fsd.py
./viterbi-out.py test.mpeg

Problems:
/tmp/atsc_pipe_5 never fills with data.
The output file, 'test.mpeg' is empty.

Question #2) What do we need to fix to get /tmp/atsc_pipe_5 to fill.
Question #3) What do we need to fix to get temp.mpeg to fill.

Thank you,
Bobby Black & Stephen Branch
address@hidden (please do not blank out this email)
black85 @ auburn . edu

Bobby Black
Auburn University
address@hidden
(334) 804-4826