QRQ CW AUDIO encoding experiment with the GSM CODEC using Gstreamer

[Chuck aa0hw]

Gstreamer encodes and decodes the CW AUDIO using the GSM AUDIO CODEC - plus - one bonus of using Gstreamer for Receiving the TRANSMIT PIPELINE, is that Gstreamer has its own CW AUDIO BANDPASS filter PLUGIN code that you can setup and use...to filter out most of the harsh harmonics, and poor sounding audio of such a low bitrate, low sample rate, AUDIO CODEC...like GSM is

TRANSMIT
gst-launch-1.0 -v jackaudiosrc ! queue ! audioconvert ! audiorate ! audioresample ! "audio/x-raw,channels=1,rate=8000" ! audioconvert ! audiorate ! audioresample ! gsmenc ! rtpgsmpay ! udpsink host=(ip address of the RECEIVER) port=5445

RECEIVE
gst-launch-1.0 -v udpsrc port=5445 ! "application/x-rtp, media=(string)audio, clock-rate=(int)8000, encoding-name=(string)GSM, payload=(int)3" ! rtpjitterbuffer ! rtpgsmdepay ! gsmdec ! audioconvert ! audiorate ! audioresample quality=10 ! audioconvert ! audiowsincband mode=band-pass lower-frequency=640 upper-frequency=840 length=400 window=hamming ! audioconvert ! audioamplify amplification=1.33 ! audiorate ! jackaudiosink