From patchwork Fri Sep 19 17:37:08 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Milan Zamazal X-Patchwork-Id: 24434 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 447D3BE173 for ; Fri, 19 Sep 2025 17:37:47 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 017A06B5B2; Fri, 19 Sep 2025 19:37:47 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="RjXQ4Yg0"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id B503B6B5A0 for ; Fri, 19 Sep 2025 19:37:44 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758303463; 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=lmNWTOBg6UB3HS/T/mVXkajSkni9mVLeYsp5zO1MAq8=; b=RjXQ4Yg0727krumJDg6p4pOXwlWglOFOlYfb0Haf/PC5OWgB9N8x01ppNC/h+zvPK7Vli5 RkWeeyTAtiTfYLoNBjr0XmL7qCx41hoAwEt94EqXiwmeeAi0e0ULGTvYIl/D6gvPKx3cvP vinxvFu4QGFVrtjyHQBvLfhivyUX6qI= Received: from mx-prod-mc-03.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-222-RodfM-rrMxilSm7KoglnTg-1; Fri, 19 Sep 2025 13:37:39 -0400 X-MC-Unique: RodfM-rrMxilSm7KoglnTg-1 X-Mimecast-MFC-AGG-ID: RodfM-rrMxilSm7KoglnTg_1758303456 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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C3ABC19560B2; Fri, 19 Sep 2025 17:37:35 +0000 (UTC) Received: from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.32.9]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 93FC11800451; Fri, 19 Sep 2025 17:37:33 +0000 (UTC) From: Milan Zamazal To: libcamera-devel@lists.libcamera.org Cc: Milan Zamazal , pobrn@protonmail.com, mail@maciej.szmigiero.name, =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= Subject: [PATCH v3 5/6] ipa: simple: blc: Prevent division by zero in BLC Date: Fri, 19 Sep 2025 19:37:08 +0200 Message-ID: <20250919173709.220881-6-mzamazal@redhat.com> In-Reply-To: <20250919173709.220881-1-mzamazal@redhat.com> References: <20250919173709.220881-1-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: pfQT4TJF7w7nCN0C3i1K-qqxjuSKU4tjv2r30MlPIvM_1758303456 X-Mimecast-Originator: redhat.com 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. Tested-by: Barnabás Pőcze Reviewed-by: Barnabás Pőcze Reviewed-by: Maciej S. Szmigiero 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..ea5356443 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 =