Forum: GNU Radio atsc

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D613139c95aec73b63e5d863db9609d3?d=identicon&s=25 unknown (Guest)
on 2009-01-23 20:19
(Received via mailing list)
I need a little help with atsc demodulation procedure, I used the
found in the README

1) Verify signal, adjust antenna and find best gain setting using,
station frequency from the fcc video database, and decimation of 10.

2) Capture data - adjust gain (-g) frequency (-f) and which side
the tvrx is on to fit your local setup: -s -R B -d 10 -g 65 -f 503e6 atsc_data_6-4m_complex---I
did not
use this command

./ -s -e eth0 -m 00:50:c2:85:30:9c -d 16 -f 519e6 -g 70
250000000 atsc_data_6-4m_complex

You probably still need fast disks to take the data, like a raid-0 set
striped sata drives. Make sure there are no or very few Ou overruns.
the raw usrp data in 'short' form halves the disk space/bus bandwidth
the usual complex form uses.

3) Make pipes:

mkfifo /tmp/atsc_pipe_1
mkfifo /tmp/atsc_pipe_2
mkfifo /tmp/atsc_pipe_3
mkfifo /tmp/atsc_pipe_4
mkfifo /tmp/atsc_pipe_5

4) In seperate windows run processes:

./ <input rf data at 6.4Msps>
./ <output mpeg transport stream>

 When I execute step 4, the scripts appear to execute properly.  When I
go to
the /tmp directory I do not see the pipes filling, the sizes remains 0.
When I
stop the execution of the scripts I do not have any data in my output
file.  Am
I missing a step with piping the files.

If I remove the pipes and execute the files sequentially (without any
First executing ./  then ./ a few seconds later
and so
on. I see the files (/tmp/atsc_pipe_(1-3) growing but not
The ''script is not saving data to /tmp/atsc_pipe_5.

I could use a little insight in executing this process.

Thank You
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