From d614eb088e1a358df6a6235d064906958ef581f6 Mon Sep 17 00:00:00 2001
From: LZ2DMV <81835377+LZ2DMV@users.noreply.github.com>
Date: Thu, 14 Mar 2024 22:47:29 +0200
Subject: [PATCH] Update Example_Usage.md

Add example for recording 48k/1 audio with rtl_fm
---
 examples/Example_Usage.md | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/examples/Example_Usage.md b/examples/Example_Usage.md
index 959c52e..dcd92b4 100644
--- a/examples/Example_Usage.md
+++ b/examples/Example_Usage.md
@@ -272,4 +272,20 @@ Note: --buffer option in play is calculated by (channels * samples * sizeof(samp
 where samples is 160 for mono, 320 for stereo, and short samples are 2 and float samples are 4.
 This is vital to prevent 'lag' or cut-off audio when the UDP audio doesn't fill the default buffer size.
 
-Note2: Be sure to start the receiving end AFTER starting DSD-FME. If DSD-FME is restarted, make sure to restart the receiving end as well, as socat/UDP closes the UDP port listening when DSD-FME closes the UDP socket.
\ No newline at end of file
+Note2: Be sure to start the receiving end AFTER starting DSD-FME. If DSD-FME is restarted, make sure to restart the receiving end as well, as socat/UDP closes the UDP port listening when DSD-FME closes the UDP socket.
+
+## Record 48k/1 audio with rtl_fm
+
+You can record suitable audio to feed as input to dsd-fme with `-i` using rtl_fm:
+
+`rtl_fm -M nfm -f [FREQ] -s 48k -g 42 -l 20 > input.wav`
+
+You can also combine that with `socat` to send the audio to a remote dsd-fme instance in real time while keeping a local copy on the host where the RTL-SDR dongle is:
+
+`rtl_fm -M fm -f [FREQ] -s 48k -g 42 -l 20 | tee input.wav | socat -u - TCP-LISTEN:1234,forever,reuseaddr`
+
+On the remote side where dsd-fme is, use the TCP input:
+
+`dsd-fme -i tcp:192.168.7.8:1234 -N`
+
+Note: As always, when using rtl_fm, play with `-l` and `-g` to find a good squelch and gain values for your environment - you will know if the squelch is the right value when `input.wav` does not increase in size in the absence of useful signal on the monitored frequency.