{"id":24443,"url":"https://patchwork.libcamera.org/api/patches/24443/?format=json","web_url":"https://patchwork.libcamera.org/patch/24443/","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":"<20250923190657.21453-5-hansg@kernel.org>","date":"2025-09-23T19:06:56","name":"[4/5] ipa: software_isp: AGC: Only use integers for exposure calculations","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"e1138d703b3e4bcc9cf6a9439c0b6dc6c4a80cea","submitter":{"id":239,"url":"https://patchwork.libcamera.org/api/people/239/?format=json","name":"Hans de Goede","email":"hansg@kernel.org"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24443/mbox/","series":[{"id":5455,"url":"https://patchwork.libcamera.org/api/series/5455/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5455","date":"2025-09-23T19:06:52","name":"ipa: software_isp: AGC: Fox AGC oscillation bug","version":1,"mbox":"https://patchwork.libcamera.org/series/5455/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24443/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24443/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 DE000C3332\n\tfor ;\n\tTue, 23 Sep 2025 19:07:17 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 39BB56B611;\n\tTue, 23 Sep 2025 21:07:17 +0200 (CEST)","from tor.source.kernel.org (tor.source.kernel.org\n\t[IPv6:2600:3c04:e001:324:0:1991:8:25])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0E80B6B5FE\n\tfor ;\n\tTue, 23 Sep 2025 21:07:07 +0200 (CEST)","from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58])\n\tby tor.source.kernel.org (Postfix) with ESMTP id 3CD416027D\n\tfor ;\n\tTue, 23 Sep 2025 19:07:06 +0000 (UTC)","by smtp.kernel.org (Postfix) with ESMTPSA id 198CEC113D0;\n\tTue, 23 Sep 2025 19:07:04 +0000 (UTC)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (2048-bit key;\n\tunprotected) header.d=kernel.org header.i=@kernel.org\n\theader.b=\"SIft1GSQ\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1758654425;\n\tbh=Vx/0xvt89XCCFLMy+c+hKznTAYPnX+/TgEK9P5I19Go=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=SIft1GSQMVoxaxoPjxT0URWNwUq1trgMiQObknjqkRl1mp/8Ae/Z29qXEGp6LVHIa\n\t1kil9OT6B026XSqRMLQu1wooxyvGufkn56i2R2+o8+JhMRVobpmJhGPQH99tbYKHOO\n\t+goOwdM3rvco8DlyMm/95+Br67HkQjXP/W6HLTbWt24uUpAM6zU8TxPgvc0iNRkg0m\n\tYnLhkW2hEbHF+Pxviw7P/xjopfHvMB7qR6QhYAU+Yj+6EzJAIKzgt+nvcz86ILDKl4\n\tOCOG0fUvvxYth1VHGiwneLyGmV5tvmYspz1mmU/SoTcsd63t0Ig03JGdU2sGoPyQ7N\n\tBMMZx7nHw2NUg==","From":"Hans de Goede ","To":"libcamera-devel@lists.libcamera.org","Cc":"Hans de Goede ","Subject":"[PATCH 4/5] ipa: software_isp: AGC: Only use integers for exposure\n\tcalculations","Date":"Tue, 23 Sep 2025 21:06:56 +0200","Message-ID":"<20250923190657.21453-5-hansg@kernel.org>","X-Mailer":"git-send-email 2.51.0","In-Reply-To":"<20250923190657.21453-1-hansg@kernel.org>","References":"<20250923190657.21453-1-hansg@kernel.org>","MIME-Version":"1.0","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":"Exposure is an integer, instead of re-using the \"double next\" used\nfor again calculations, doing intermediate calculations with double\nprecision, use a local next variable of an integer type.\n\nSigned-off-by: Hans de Goede \n---\n src/ipa/simple/algorithms/agc.cpp | 9 ++++-----\n 1 file changed, 4 insertions(+), 5 deletions(-)","diff":"diff --git a/src/ipa/simple/algorithms/agc.cpp b/src/ipa/simple/algorithms/agc.cpp\nindex 230616e62..cdde56ba2 100644\n--- a/src/ipa/simple/algorithms/agc.cpp\n+++ b/src/ipa/simple/algorithms/agc.cpp\n@@ -51,19 +51,18 @@ void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, dou\n \tstatic constexpr uint8_t kExpNumeratorUp = kExpDenominator + 1;\n \tstatic constexpr uint8_t kExpNumeratorDown = kExpDenominator - 1;\n \n-\tdouble next;\n \tint32_t &exposure = frameContext.sensor.exposure;\n \tdouble &again = frameContext.sensor.gain;\n \n \tif (exposureMSV < kExposureOptimal - kExposureSatisfactory) {\n \t\tif (exposure < context.configuration.agc.exposureMax) {\n-\t\t\tnext = exposure * kExpNumeratorUp / kExpDenominator;\n+\t\t\tint32_t next = exposure * kExpNumeratorUp / kExpDenominator;\n \t\t\tif (next - exposure < 1)\n \t\t\t\texposure += 1;\n \t\t\telse\n \t\t\t\texposure = next;\n \t\t} else {\n-\t\t\tnext = again * kExpNumeratorUp / kExpDenominator;\n+\t\t\tdouble next = again * kExpNumeratorUp / kExpDenominator;\n \t\t\tif (next - again < context.configuration.agc.againMinStep)\n \t\t\t\tagain += context.configuration.agc.againMinStep;\n \t\t\telse\n@@ -73,13 +72,13 @@ void Agc::updateExposure(IPAContext &context, IPAFrameContext &frameContext, dou\n \n \tif (exposureMSV > kExposureOptimal + kExposureSatisfactory) {\n \t\tif (again > context.configuration.agc.againDef) {\n-\t\t\tnext = again * kExpNumeratorDown / kExpDenominator;\n+\t\t\tdouble next = again * kExpNumeratorDown / kExpDenominator;\n \t\t\tif (again - next < context.configuration.agc.againMinStep)\n \t\t\t\tagain -= context.configuration.agc.againMinStep;\n \t\t\telse\n \t\t\t\tagain = next;\n \t\t} else {\n-\t\t\tnext = exposure * kExpNumeratorDown / kExpDenominator;\n+\t\t\tint32_t next = exposure * kExpNumeratorDown / kExpDenominator;\n \t\t\tif (exposure - next < 1)\n \t\t\t\texposure -= 1;\n \t\t\telse\n","prefixes":["4/5"]}