{"id":24435,"url":"https://patchwork.libcamera.org/api/patches/24435/?format=json","web_url":"https://patchwork.libcamera.org/patch/24435/","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":"<20250919173709.220881-7-mzamazal@redhat.com>","date":"2025-09-19T17:37:09","name":"[v3,6/6] ipa: simple: agc: Prevent division by zero in AGC","commit_ref":null,"pull_url":null,"state":"superseded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/24435/mbox/","series":[{"id":5451,"url":"https://patchwork.libcamera.org/api/series/5451/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5451","date":"2025-09-19T17:37:03","name":"Fix stats related problems in software ISP","version":3,"mbox":"https://patchwork.libcamera.org/series/5451/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24435/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24435/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 83098C3329\n\tfor ;\n\tFri, 19 Sep 2025 17:37:48 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id F35096B5AC;\n\tFri, 19 Sep 2025 19:37:47 +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 BD2316B5A9\n\tfor ;\n\tFri, 19 Sep 2025 19:37:44 +0200 (CEST)","from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com\n\t(ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97])\n\tby relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n\tcipher=TLS_AES_256_GCM_SHA384) id us-mta-119-3J46Uw-AOqG9-2XGz91bHA-1;\n\tFri, 19 Sep 2025 13:37:40 -0400","from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com\n\t(mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com\n\t[10.30.177.111])\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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTPS id A0A0D1800576; Fri, 19 Sep 2025 17:37:38 +0000 (UTC)","from mzamazal-thinkpadp1gen7.tpbc.com (unknown [10.44.32.9])\n\tby mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix)\n\twith ESMTP id 6615C1800451; Fri, 19 Sep 2025 17:37:36 +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=\"D2F58Y7v\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n\ts=mimecast20190719; t=1758303463;\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=8Ar7rPvF0560/BLcKfYhFP4NTCURP5c0LZstSfMrNDk=;\n\tb=D2F58Y7vlVGX8HMD9w6fUzGqWQGLOXUJX0PiwXIC6Z0ag6MEnITFmbcDCviWKDRiV6S7uc\n\tWV+4A/+CgUr6I7hVDHSAkANcF34vIMimLM4PlUz5r/dAEQ/5BhiIRDX9HFFRaXYi9X4dQe\n\tZxOzY42LGRx4z+axn6w1hxdR7Uv7NRU=","X-MC-Unique":"3J46Uw-AOqG9-2XGz91bHA-1","X-Mimecast-MFC-AGG-ID":"3J46Uw-AOqG9-2XGz91bHA_1758303459","From":"Milan Zamazal ","To":"libcamera-devel@lists.libcamera.org","Cc":"Milan Zamazal , pobrn@protonmail.com,\n\tmail@maciej.szmigiero.name, =?utf-8?q?Barnab=C3=A1s_P=C5=91cze?=\n\t","Subject":"[PATCH v3 6/6] ipa: simple: agc: Prevent division by zero in AGC","Date":"Fri, 19 Sep 2025 19:37:09 +0200","Message-ID":"<20250919173709.220881-7-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":"5HnV9zTyYulShwp5V8K67mVx5uo-rKq2FzKczDRFsb8_1758303459","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":"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\nTested-by: Barnabás Pőcze \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":["v3","6/6"]}