From ef0b475f471e114044a7fbacf13bb16b5d362def Mon Sep 17 00:00:00 2001 From: Milan Zamazal Date: Thu, 21 Aug 2025 15:41:41 +0200 Subject: [PATCH 05/17] libcamera: simple: Prevent division by zero in BLC When there are no values in the histogram, BLC simple IPA can crash on division by zero. We cannot get anything meaningful in such a case anyway, let's simply return from `process()' then. Signed-off-by: Milan Zamazal --- src/ipa/simple/algorithms/blc.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/ipa/simple/algorithms/blc.cpp b/src/ipa/simple/algorithms/blc.cpp index 8c1e9ed08..71731c6f6 100644 --- a/src/ipa/simple/algorithms/blc.cpp +++ b/src/ipa/simple/algorithms/blc.cpp @@ -77,6 +77,11 @@ void BlackLevel::process(IPAContext &context, constexpr float ignoredPercentage = 0.02; const unsigned int total = std::accumulate(begin(histogram), end(histogram), 0); + if (total == 0) { + LOG(IPASoftBL, Debug) << "Not guessing black level, histogram is empty"; + return; + }; + const unsigned int pixelThreshold = ignoredPercentage * total; const unsigned int histogramRatio = 256 / SwIspStats::kYHistogramSize; const unsigned int currentBlackIdx = -- 2.50.1