test sending CW over IP with the EAC3 codec at Zero Hertz - demod the RX signal with a soundcard SDR

\

brief test to see how well the EAC3 CODEC can reconstruct the ON /OFF cw element framework of Morse Code from a CW KEYER sending CW at "0" hz

NOTE: test starts out at QRQ speeds, then CW speed goes down to 20wpm, gradually back up again and over 100 wpm, then back down, to give an idea of how this experimental Morse Code over IP setup performs at all speeds

Gstreamer provides the audio over ip pathways..

GSTREAMER EAC3 TRANSMITTER SCRIPT:

*********************************************

gst-launch-1.0 -v jackaudiosrc ! "audio/x-raw, format=(string)F32LE, layout=(string)interleaved, rate=(int)48000, channels=(int)1" ! audioconvert ! avenc_eac3 ! rtpgstpay ! queue ! udpsink host=(ip address of Receiver) port=5555

GSTREAMER EAC3 RECEIVER SRIPT:

**************************************

gst-launch-1.0 -v udpsrc port=5555 ! "application/x-rtp, media=(string)application, clock-rate=(int)90000, encoding-name=(string)X-GST, caps=(string)\"YXVkaW8veC1lYWMzLCBjaGFubmVscz0oaW50KTEsIHJhdGU9KGludCk0ODAwMA\=\=\", capsversion=(string)0, payload=(int)96" ! rtpjitterbuffer ! rtpgstdepay ! avdec_eac3 ! audioconvert ! jackaudiosink

NOTE: since the RECEIVE signal has ZERO RISE/FALL time, 2 tandem CW BANDPASS FILTERS were used to provide raised cosine CW ELEMENT edge shaping, which can be varied to suit the listener by adjusting the Recri Keyer FILT module cw bandpass options(especially the "length" setting)

CW KEYBOARD and FILTERs and SDR modules are from Recri Keyer:

https://github.com/recri/keyer

GSTREAMER - has versions for all OS(es)

https://gstreamer.freedesktop.org/download/

EAC3 CODEC (aka Dolby Digital Plus)

https://en.wikipedia.org/wiki/Dolby_Digital_Plus

Views: 12

Comment

You need to be a member of QRQcw to add comments!

Join QRQcw

© 2021   Created by Chuck aa0hw.   Powered by

Badges  |  Report an Issue  |  Terms of Service