From patchwork Thu Aug 21 13:41:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 24174 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 9A231BEFBE for ; Thu, 21 Aug 2025 13:42:10 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 5A698692ED; Thu, 21 Aug 2025 15:42:10 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="LJqq8SIO"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 5C76669257 for ; Thu, 21 Aug 2025 15:42:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755783728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KMRZfXmG+aUPlclYMk6hPyaAt+ixcRkQlW0Jn7FZTro=; b=LJqq8SIO3G8Sm8OLXpoD+82uAMsG2frNj0F1v1+a+H3hwAxXskIbeD26zAt2WuN9zpj54F f002UCV5R4DRKCzdnq3wP0pVZiXhgEAHzQnfQUz0ANzahqq2h0avo09R58lG+/M3iXKZlO 50BHMYRMD0ARjJbxyMlzf9MNY9wxou8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-375-mta7ESvZNnSo9hdAa00arA-1; Thu, 21 Aug 2025 09:42:02 -0400 X-MC-Unique: mta7ESvZNnSo9hdAa00arA-1 X-Mimecast-MFC-AGG-ID: mta7ESvZNnSo9hdAa00arA_1755783721 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9B362195608A; Thu, 21 Aug 2025 13:42:01 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.45.224.162]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id BF20A180029B; Thu, 21 Aug 2025 13:41:59 +0000 (UTC) From: Milan Zamazal To: libcamera-devel@lists.libcamera.org Cc: Milan Zamazal , pobrn@protonmail.com, mail@maciej.szmigiero.name Subject: [PATCH 5/5] libcamera: simple: Prevent division by zero in BLC Date: Thu, 21 Aug 2025 15:41:41 +0200 Message-ID: <20250821134141.83236-6-mzamazal@redhat.com> In-Reply-To: <20250821134141.83236-1-mzamazal@redhat.com> References: <20250821134141.83236-1-mzamazal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 1cZxlQJAJ0U8ypNAe53BvVcnbiOY7qaNjm85xmmK0LQ_1755783721 X-Mimecast-Originator: redhat.com content-type: text/plain; charset="US-ASCII"; x-default=true X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" 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 Tested-by: Barnabás Pőcze Reviewed-by: Barnabás Pőcze --- 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 =