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{ "id": 24462, "url": "https://patchwork.libcamera.org/api/1.1/covers/24462/?format=api", "web_url": "https://patchwork.libcamera.org/cover/24462/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20250925221708.7471-1-hansg@kernel.org>", "date": "2025-09-25T22:17:02", "name": "[v2,0/6] ipa: software_isp: AGC: Fox AGC oscillation bug", "submitter": { "id": 239, "url": "https://patchwork.libcamera.org/api/1.1/people/239/?format=api", "name": "Hans de Goede", "email": "hansg@kernel.org" }, "mbox": "https://patchwork.libcamera.org/cover/24462/mbox/", "series": [ { "id": 5459, "url": "https://patchwork.libcamera.org/api/1.1/series/5459/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5459", "date": "2025-09-25T22:17:02", "name": "ipa: software_isp: AGC: Fox AGC oscillation bug", "version": 2, "mbox": "https://patchwork.libcamera.org/series/5459/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/covers/24462/comments/", "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "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 C07B3BDB1C\n\tfor <parsemail@patchwork.libcamera.org>;\n\tThu, 25 Sep 2025 22:17:15 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 2F1666B5F3;\n\tFri, 26 Sep 2025 00:17:14 +0200 (CEST)", "from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 86D8169367\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tFri, 26 Sep 2025 00:17:12 +0200 (CEST)", "from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58])\n\tby tor.source.kernel.org (Postfix) with ESMTP id 53D8361286\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 25 Sep 2025 22:17:11 +0000 (UTC)", "by smtp.kernel.org (Postfix) with ESMTPSA id 4A3F9C4CEF0;\n\tThu, 25 Sep 2025 22:17:10 +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=\"uRT5Tm56\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1758838631;\n\tbh=geaAGomfoU3nVXua/rvmm8NuY1XnVf8ntSt8C9rtvuk=;\n\th=From:To:Cc:Subject:Date:From;\n\tb=uRT5Tm56kNDvezbNhkp4Dmrl9WDsqKmCVPZ83lveYj01u5BnddAKe7swW+/LmoKK2\n\t8/RFwyK+JyFR+IQXjW/wWaNObdVLxK8F4KV2rG9uuaBnX4FgYiWJEAy8pwxDXuJpXT\n\tvDwTmNTgt3lTsLtywd/9AC+F9wflhUWqvtlbWs+AlIjo8orKIEtlQpxKIO96dusPCX\n\tLdtO3IbI06nSwwQqUxkxADee8Z9/eIZXiItE8BdHyLEyygUmUSsFCcl98eT2QKKw8u\n\tVQVud5SJvCR85mao1xgIxtCQNjJdZ+vKnnFoNIuf+m9HmliLkNXN0KCtZpSH7ntAid\n\t7Q+rcCjcwV8eA==", "From": "Hans de Goede <hansg@kernel.org>", "To": "libcamera-devel@lists.libcamera.org", "Cc": "Hans de Goede <hansg@kernel.org>", "Subject": "[PATCH v2 0/6] ipa: software_isp: AGC: Fox AGC oscillation bug", "Date": "Fri, 26 Sep 2025 00:17:02 +0200", "Message-ID": "<20250925221708.7471-1-hansg@kernel.org>", "X-Mailer": "git-send-email 2.51.0", "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": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "Hi All,\n\nDue to a combination of not having correct control-delay information for\nvarious sensors as well as the generic nature of the simple-pipeline +\nsoftware-ISP meaning that any pipeline delays are unknown it is impossible\nto get reliable control-delay values.\n\nWrong control-delay values can lead to pretty bad oscilation. See the v1\ncover-letter for more details.\n\nThis series fixes some unrelated issues in the softIPA AGC algorithm\nand in the last 2 patches addresses the oscillation issue. Note this v2\ntakes a new approach to fixing the oscilation by only generating statistics\nfor every 4th frame and having the IPA only run its algorithms when there\nactually are statistics. This saves CPU time, while at the same time\navoiding the oscillation issue.\n\nChanges in v2:\n- Skip running IPA algorithms when there are no statistics\n- Only generate statistics for every 4th frame\n\nNote the speed of the AGC algorithm converges on the desired brightness\nlevel is unchanged compared to v1 since in v1 the AGC algorithm would\nskip 3 frames after every gain/exposure change.\n\nRegards,\n\nHans\n\n\nHans de Goede (6):\n ipa: software_isp: Fix context_.configuration.agc.againMin init\n ipa: software_isp: AGC: Do not lower gain below 1.0\n ipa: software_isp: AGC: Raise exposure or gain not both at the same\n time\n ipa: software_isp: AGC: Only use integers for exposure calculations\n libcamera: software_isp: Add valid flag to struct SwIspStats\n libcamera: software_isp: Run sw-statistics once every 4th frame\n\n .../internal/software_isp/swisp_stats.h | 4 +++\n src/ipa/simple/algorithms/agc.cpp | 26 ++++++++++---------\n src/ipa/simple/algorithms/awb.cpp | 3 +++\n src/ipa/simple/algorithms/blc.cpp | 3 +++\n src/ipa/simple/ipa_context.h | 2 +-\n src/ipa/simple/soft_simple.cpp | 10 ++++++-\n src/libcamera/software_isp/debayer_cpu.cpp | 25 +++++++++++-------\n src/libcamera/software_isp/debayer_cpu.h | 4 +--\n src/libcamera/software_isp/swstats_cpu.cpp | 9 ++++++-\n src/libcamera/software_isp/swstats_cpu.h | 5 +++-\n 10 files changed, 63 insertions(+), 28 deletions(-)" }