A CW audio bandpass filter for QRQ CW - using a Gstreamer PIPELINE script which includes the filter

[Chuck aa0hw]

Experimental test to see how well a Gstreamer AUDIO OVER IP pipeline can (also)filter CW AUDIO headed for the LINE INPUT of a RIG for CW TRANSMIT using AFCW MODE on HF SSB(remote rig over Ethernet LAN setup using a Raspberry PI2b::RIG interface)

Here is the Gstreamer script that includes the additional script for the CW AUDIO BANDPASS FILTERING function:

this is the part of the script that has the audio bandpass feature:
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"audiowsincband mode=band-pass lower-frequency=580 upper-frequency=780 length=400 window=hamming"

THIS IS THE WHOLE GSTREAMER SCRIPT:
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pi@raspberrypi ~ $ gst-launch-1.0 -v jackaudiosrc ! audio/x-raw, endianness=1234, signed=true, width=32, depth=32, rate=48000, channels=1, format=F32LE ! audioconvert ! audiowsincband mode=band-pass lower-frequency=580 upper-frequency=780 length=400 window=hamming ! audioconvert ! queue ! tcpserversink host=192.168.1.130 port=3000

NOTE: instead of going to the rig, this example 'sent' the CW AUDIO FILE being played by the AD5DZ software CW KEYBOARD, to this recording Linux laptop for analysis and recording...
NOTE: there were a couple of audio POPs heard during this recording...usually caused by the SPAN WINDOWS VST plugin taxing the CPU and having the video recorder set to 60 frames /second...

HERE IS A PICTURE of a dit at 130 wpm WITHOUT(left) and WITH(right) the Gstreamer bandpass filter code

Below is a SPECTRUM ANALYSIS of the CW EDGE noise below and above the main CW PITCH...without(left) and with(right) the Gstreamer Bandpass filter coded into the pipeline