From 95e3a60df0d129f5f1493be4ce1754f73c3a7d4a Mon Sep 17 00:00:00 2001
From: Andy Piper <github@andypiper.com>
Date: Sat, 7 Dec 2024 16:20:40 +0000
Subject: [PATCH] AP_HAL: protect against invalid values when calculating
 Jain's estimator

---
 libraries/AP_HAL/DSP.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libraries/AP_HAL/DSP.cpp b/libraries/AP_HAL/DSP.cpp
index 10b33e38d07ef..932149d9726c7 100644
--- a/libraries/AP_HAL/DSP.cpp
+++ b/libraries/AP_HAL/DSP.cpp
@@ -286,6 +286,11 @@ float DSP::calculate_jains_estimator(const FFTWindowState* fft, const float* rea
     float y1 = real_fft[k_max-1];
     float y2 = real_fft[k_max];
     float y3 = real_fft[k_max+1];
+
+    if (is_zero(y2) || is_zero(y1)) {
+        return 0.0f;
+    }
+
     float d = 0.0f;
 
     if (y1 > y3) {