{"id":24326,"url":"https://patchwork.libcamera.org/api/patches/24326/?format=json","web_url":"https://patchwork.libcamera.org/patch/24326/","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":"<20250911135144.56586-7-mzamazal@redhat.com>","date":"2025-09-11T13:51:44","name":"[v2,6/6] ipa: simple: agc: Prevent division by zero in AGC","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"a9f874f09af504b37b52144ceb0635a4135d210e","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/24326/mbox/","series":[{"id":5432,"url":"https://patchwork.libcamera.org/api/series/5432/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5432","date":"2025-09-11T13:51:39","name":"Fix stats related problems in software ISP","version":2,"mbox":"https://patchwork.libcamera.org/series/5432/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24326/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24326/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 942A6C324E\n\tfor ;\n\tThu, 11 Sep 2025 13:52:16 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 44F2869381;\n\tThu, 11 Sep 2025 15:52:16 +0200 (CEST)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.133.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 627C569378\n\tfor ;\n\tThu, 11 Sep 2025 15:52:12 +0200 (CEST)","from mx-prod-mc-03.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-486-WSsWQtFBMz2e4LJAXL_JCQ-1;\n\tThu, 11 Sep 2025 09:52:08 -0400","from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com\n\t(mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com\n\t[10.30.177.93])\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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTPS id CE97B1944F03; Thu, 11 Sep 2025 13:52:06 +0000 (UTC)","from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.34.98])\n\tby mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTP id 0BB0018003FC; Thu, 11 Sep 2025 13:52:04 +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=\"TYIeP2Td\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n\ts=mimecast20190719; t=1757598731;\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=Nhfze4fx9JEI2w/6L9bi0ryB6jhMwfk6MPMUuFJ0Bps=;\n\tb=TYIeP2Td5g7e1r2LyDmw72FC3OM/wkTjFrTT5Z1LbAv5f1cx4Tj0T1ZJunU567s7j9JWJO\n\ticzlhCIQOpzisQ1h3EgJeCkRDVBcc8Ki4Q/NyyZLzU5budzN7Q3wU6VVpfdNwF3Es8epMl\n\tYqCZe1fN0t0s+lIev9FXqYOpYN79H4A=","X-MC-Unique":"WSsWQtFBMz2e4LJAXL_JCQ-1","X-Mimecast-MFC-AGG-ID":"WSsWQtFBMz2e4LJAXL_JCQ_1757598727","From":"Milan Zamazal ","To":"libcamera-devel@lists.libcamera.org","Cc":"Milan Zamazal , pobrn@protonmail.com,\n\tmail@maciej.szmigiero.name","Subject":"[PATCH v2 6/6] ipa: simple: agc: Prevent division by zero in AGC","Date":"Thu, 11 Sep 2025 15:51:44 +0200","Message-ID":"<20250911135144.56586-7-mzamazal@redhat.com>","In-Reply-To":"<20250911135144.56586-1-mzamazal@redhat.com>","References":"<20250911135144.56586-1-mzamazal@redhat.com>","MIME-Version":"1.0","X-Scanned-By":"MIMEDefang 3.4.1 on 10.30.177.93","X-Mimecast-Spam-Score":"0","X-Mimecast-MFC-PROC-ID":"zz3ZmttqmDylewnMNVAKXmWFietCh-6acAH8KlW49Uw_1757598727","X-Mimecast-Originator":"redhat.com","Content-Transfer-Encoding":"8bit","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":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"If the histogram size is non-zero but lower than the number of bins,\nyHistValsPerBin is zero and then the AGC processing crashes on division\nby it. Let's check yHistValsPerBin for being zero and stop AGC\nprocessing in such a case. The condition also covers the cases where\nhistogramSize or yHistValsPerBinMod are zero.\n\nSigned-off-by: Milan Zamazal \n---\n src/ipa/simple/algorithms/agc.cpp | 6 ++++++\n 1 file changed, 6 insertions(+)","diff":"diff --git a/src/ipa/simple/algorithms/agc.cpp b/src/ipa/simple/algorithms/agc.cpp\nindex c46bb0ebe..e47949ec4 100644\n--- a/src/ipa/simple/algorithms/agc.cpp\n+++ b/src/ipa/simple/algorithms/agc.cpp\n@@ -124,6 +124,12 @@ void Agc::process(IPAContext &context,\n \tunsigned int denom = 0;\n \tunsigned int num = 0;\n \n+\tif (yHistValsPerBin == 0) {\n+\t\tLOG(IPASoftExposure, Debug)\n+\t\t\t<< \"Not adjusting exposure due to insufficient histogram data\";\n+\t\treturn;\n+\t}\n+\n \tfor (unsigned int i = 0; i < histogramSize; i++) {\n \t\tunsigned int idx = (i - (i / yHistValsPerBinMod)) / yHistValsPerBin;\n \t\texposureBins[idx] += histogram[blackLevelHistIdx + i];\n","prefixes":["v2","6/6"]}