{"id":24492,"url":"https://patchwork.libcamera.org/api/patches/24492/?format=json","web_url":"https://patchwork.libcamera.org/patch/24492/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250929201924.45019-5-mzamazal@redhat.com>","date":"2025-09-29T20:19:21","name":"[v5,4/7] ipa: simple: awb: Avoid incorrect arithmetic in AWB","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"3c7eb37701b8ebc791cab079a35f244cc115ec60","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/?format=json","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24492/mbox/","series":[{"id":5466,"url":"https://patchwork.libcamera.org/api/series/5466/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5466","date":"2025-09-29T20:19:17","name":"Fix stats related problems in software ISP","version":5,"mbox":"https://patchwork.libcamera.org/series/5466/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24492/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24492/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 7DF67C324C\n\tfor ;\n\tMon, 29 Sep 2025 20:19:54 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id D21816B62C;\n\tMon, 29 Sep 2025 22:19:53 +0200 (CEST)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7F25F6B61A\n\tfor ;\n\tMon, 29 Sep 2025 22:19:48 +0200 (CEST)","from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com\n\t(ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63])\n\tby relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n\tcipher=TLS_AES_256_GCM_SHA384) id us-mta-687-i5MYK76fM-W8Kc-1iVSYAQ-1;\n\tMon, 29 Sep 2025 16:19:46 -0400","from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com\n\t(mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com\n\t[10.30.177.12])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\tkey-exchange X25519 server-signature RSA-PSS (2048 bits)\n\tserver-digest SHA256) (No client certificate requested)\n\tby mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTPS id 54AC01956096; Mon, 29 Sep 2025 20:19:44 +0000 (UTC)","from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.32.35])\n\tby mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTP id C2D3D19560B4; Mon, 29 Sep 2025 20:19:41 +0000 (UTC)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=redhat.com header.i=@redhat.com\n\theader.b=\"K3hB9RUa\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n\ts=mimecast20190719; t=1759177187;\n\th=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n\tto:to:cc:cc:mime-version:mime-version:content-type:content-type:\n\tcontent-transfer-encoding:content-transfer-encoding:\n\tin-reply-to:in-reply-to:references:references;\n\tbh=lDb09VGyzhqP5r/oXwXiq9KLrF0OQQgUEyOYPhJgWx4=;\n\tb=K3hB9RUag8UI4cQ9CB4jJfay9IY5OTDVcKCks9C8PPRSbXzqCPqbG5Uk4eaK3tq+Vs1TeZ\n\tHmKyev8l6dGeag2ln+L1YburFSYNnqrlrf5b9/8/JleikfieVfKEpmwCpBoFvxsMNk7++V\n\taS87At41tCSjcQsMBEvEUNcWcq2wxSw=","X-MC-Unique":"i5MYK76fM-W8Kc-1iVSYAQ-1","X-Mimecast-MFC-AGG-ID":"i5MYK76fM-W8Kc-1iVSYAQ_1759177184","From":"Milan Zamazal ","To":"libcamera-devel@lists.libcamera.org","Cc":"Milan Zamazal , pobrn@protonmail.com,\n\tmail@maciej.szmigiero.name, hansg@kernel.org, =?utf-8?b?QmFybmFiw6Fz?=\n\t=?utf-8?q?_P=C5=91cze?= ","Subject":"[PATCH v5 4/7] ipa: simple: awb: Avoid incorrect arithmetic in AWB","Date":"Mon, 29 Sep 2025 22:19:21 +0200","Message-ID":"<20250929201924.45019-5-mzamazal@redhat.com>","In-Reply-To":"<20250929201924.45019-1-mzamazal@redhat.com>","References":"<20250929201924.45019-1-mzamazal@redhat.com>","MIME-Version":"1.0","X-Scanned-By":"MIMEDefang 3.0 on 10.30.177.12","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"rNAZ5FGjfqLdJn9BSPr6C-I_WTo14QxPAWT6I5OlH1g_1759177184","X-Mimecast-Originator":"redhat.com","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"8bit","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"The R/G/B sums computed in AWB simple IPA may be zero or perhaps even\nnegative. Let's make sure the sums are always positive, to prevent\ndivision by zero or completely nonsense results.\n\nSigned-off-by: Milan Zamazal \nReviewed-by: Barnabás Pőcze \nReviewed-by: Hans de Goede \n---\n src/ipa/simple/algorithms/awb.cpp | 8 +++++---\n 1 file changed, 5 insertions(+), 3 deletions(-)","diff":"diff --git a/src/ipa/simple/algorithms/awb.cpp b/src/ipa/simple/algorithms/awb.cpp\nindex cf567e894..b1eb7d310 100644\n--- a/src/ipa/simple/algorithms/awb.cpp\n+++ b/src/ipa/simple/algorithms/awb.cpp\n@@ -7,6 +7,7 @@\n \n #include \"awb.h\"\n \n+#include \n #include \n #include \n \n@@ -69,9 +70,10 @@ void Awb::process(IPAContext &context,\n \tconst uint64_t nPixels = std::accumulate(\n \t\thistogram.begin(), histogram.end(), 0);\n \tconst uint64_t offset = blackLevel * nPixels;\n-\tconst uint64_t sumR = stats->sumR_ - offset / 4;\n-\tconst uint64_t sumG = stats->sumG_ - offset / 2;\n-\tconst uint64_t sumB = stats->sumB_ - offset / 4;\n+\tconst uint64_t minValid = 1;\n+\tconst uint64_t sumR = stats->sumR_ > offset / 4 ? stats->sumR_ - offset / 4 : minValid;\n+\tconst uint64_t sumG = stats->sumG_ > offset / 2 ? stats->sumG_ - offset / 2 : minValid;\n+\tconst uint64_t sumB = stats->sumB_ > offset / 4 ? stats->sumB_ - offset / 4 : minValid;\n \n \t/*\n \t * Calculate red and blue gains for AWB.\n","prefixes":["v5","4/7"]}