Record (HDMI Rx) : Records the audio data into a file.
gst-launch-1.0 alsasrc device=hw:0,1 ! queue ! audio/x-raw,format=S24_32LE,rate=48000,channnels=2 ! filesink location=<output filename.raw>
Playback (HDMI Tx): Playing the recorded file from above step
gst-launch-1.0 filesrc location=<output filename.raw> ! audio/x-raw,format=S24_32LE,rate=48000,channnels=2 ! alsasink device=hw:0,0