From ebbfd76504101658ee85c83546e55c9aa1c5ab5b Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Tue, 21 Apr 2026 19:56:15 +0000
Subject: [PATCH] Harden USRP callback interpolation factor and length handling

Agent-Logs-Url: https://github.com/srcejon/sdrangel/sessions/bafbe6fb-a6ec-4ee0-92f8-caa27da815f5

Co-authored-by: srcejon <57259258+srcejon@users.noreply.github.com>
---
 plugins/samplesink/usrpoutput/usrpoutputthread.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/plugins/samplesink/usrpoutput/usrpoutputthread.cpp b/plugins/samplesink/usrpoutput/usrpoutputthread.cpp
index c8209c75c..e158eb4eb 100644
--- a/plugins/samplesink/usrpoutput/usrpoutputthread.cpp
+++ b/plugins/samplesink/usrpoutput/usrpoutputthread.cpp
@@ -123,22 +123,27 @@ void USRPOutputThread::run()
 //  Interpolate according to specified log2 (ex: log2=4 => decim=16)
 void USRPOutputThread::callback(qint16* buf, qint32 len)
 {
+    if (len <= 0) {
+        return;
+    }
+
+    const unsigned int interpolationFactor = 1U << m_log2Interp;
     SampleVector& data = m_sampleFifo->getData();
     unsigned int iPart1Begin, iPart1End, iPart2Begin, iPart2End;
-    m_sampleFifo->read(len/(1<<m_log2Interp), iPart1Begin, iPart1End, iPart2Begin, iPart2End);
+    m_sampleFifo->read(static_cast<unsigned int>(len)/interpolationFactor, iPart1Begin, iPart1End, iPart2Begin, iPart2End);
 
     if (iPart1Begin != iPart1End) {
         callbackPart(buf, data, iPart1Begin, iPart1End);
     }
 
-    unsigned int shift = (iPart1End - iPart1Begin)*(1<<m_log2Interp);
+    unsigned int shift = (iPart1End - iPart1Begin)*interpolationFactor;
 
     if (iPart2Begin != iPart2End) {
         callbackPart(buf + 2*shift, data, iPart2Begin, iPart2End);
     }
 
     const unsigned int writtenSamples =
-            ((iPart1End - iPart1Begin) + (iPart2End - iPart2Begin)) * (1U << m_log2Interp);
+            ((iPart1End - iPart1Begin) + (iPart2End - iPart2Begin)) * interpolationFactor;
 
     if (writtenSamples < static_cast<unsigned int>(len))
     {