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{ "id": 27482, "url": "https://patchwork.libcamera.org/api/patches/27482/?format=api", "web_url": "https://patchwork.libcamera.org/patch/27482/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/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": "<20260723154327.1357866-34-barnabas.pocze@ideasonboard.com>", "date": "2026-07-23T15:43:16", "name": "[RFC,v2,33/43] ipa: simple: agc: Separate MSV calculation", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "b75ad0e58f581454e9100ff5f5766b9eebc0a8a2", "submitter": { "id": 216, "url": "https://patchwork.libcamera.org/api/people/216/?format=api", "name": "Barnabás Pőcze", "email": "barnabas.pocze@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/27482/mbox/", "series": [ { "id": 6075, "url": "https://patchwork.libcamera.org/api/series/6075/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=6075", "date": "2026-07-23T15:42:43", "name": "ipa: libipa: agc rework", "version": 2, "mbox": "https://patchwork.libcamera.org/series/6075/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/27482/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/27482/checks/", "tags": {}, "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 7A3AFC32CE\n\tfor <parsemail@patchwork.libcamera.org>;\n\tThu, 23 Jul 2026 15:44:19 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0455767F52;\n\tThu, 23 Jul 2026 17:44:19 +0200 (CEST)", "from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id F1AA667EFB\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 23 Jul 2026 17:43:38 +0200 (CEST)", "from pb-laptop.local (185.182.215.156.nat.pool.zt.hu\n\t[185.182.215.156])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 1FA7D23B9\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 23 Jul 2026 17:42:38 +0200 (CEST)" ], "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"oGKB23Ux\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1784821358;\n\tbh=JnG6U3ReObdvdyhBhEGao+Rl2y+v4KH1tXn9bxTK8yA=;\n\th=From:To:Subject:Date:In-Reply-To:References:From;\n\tb=oGKB23Uxq3lpJ3g8BobRu7vuXdJI3urZO0s72+3+QygrniQPidkgV3O1MRjHFYbNx\n\ti41OrtWNwYlf2M7l2GsReTa16lMeyNh7GFhz3tlF7jKFKM1TkGdeZVXlHqVCEvhULc\n\thdiUIsq8pgyxJ8gGa/JdFofbyETwJ9APSGqzA2vI=", "From": "=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= <barnabas.pocze@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Subject": "[RFC PATCH v2 33/43] ipa: simple: agc: Separate MSV calculation", "Date": "Thu, 23 Jul 2026 17:43:16 +0200", "Message-ID": "<20260723154327.1357866-34-barnabas.pocze@ideasonboard.com>", "X-Mailer": "git-send-email 2.55.0", "In-Reply-To": "<20260723154327.1357866-1-barnabas.pocze@ideasonboard.com>", "References": "<20260723154327.1357866-1-barnabas.pocze@ideasonboard.com>", "MIME-Version": "1.0", "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": "<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": "Add a separate function that does the MSV calculation.\n\nSigned-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>\n---\n src/ipa/simple/algorithms/agc.cpp | 72 ++++++++++++++++++-------------\n 1 file changed, 42 insertions(+), 30 deletions(-)", "diff": "diff --git a/src/ipa/simple/algorithms/agc.cpp b/src/ipa/simple/algorithms/agc.cpp\nindex 93505f7665..f959abeba5 100644\n--- a/src/ipa/simple/algorithms/agc.cpp\n+++ b/src/ipa/simple/algorithms/agc.cpp\n@@ -9,6 +9,7 @@\n \n #include <algorithm>\n #include <cmath>\n+#include <optional>\n #include <stdint.h>\n \n #include <libcamera/base/log.h>\n@@ -61,6 +62,44 @@ static constexpr float kExpProportionalGain = 0.04;\n */\n static constexpr float kExpMaxStep = 0.15;\n \n+namespace {\n+\n+std::optional<float> calculateMSV(const SwIspStats::Histogram &histogram, uint8_t blackLevel)\n+{\n+\t/*\n+\t * Calculate Mean Sample Value (MSV) according to formula from:\n+\t * https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf\n+\t */\n+\tconst unsigned int blackLevelHistIdx =\n+\t\tblackLevel / (256 / SwIspStats::kYHistogramSize);\n+\tconst unsigned int histogramSize =\n+\t\tSwIspStats::kYHistogramSize - blackLevelHistIdx;\n+\tconst unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;\n+\tconst unsigned int yHistValsPerBinMod =\n+\t\thistogramSize / (histogramSize % kExposureBinsCount + 1);\n+\tint exposureBins[kExposureBinsCount] = {};\n+\tunsigned int denom = 0;\n+\tunsigned int num = 0;\n+\n+\tif (yHistValsPerBin == 0)\n+\t\treturn {};\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+\t}\n+\n+\tfor (unsigned int i = 0; i < kExposureBinsCount; i++) {\n+\t\tLOG(IPASoftExposure, Debug) << i << \": \" << exposureBins[i];\n+\t\tdenom += exposureBins[i];\n+\t\tnum += exposureBins[i] * (i + 1);\n+\t}\n+\n+\treturn (denom == 0 ? 0 : static_cast<float>(num) / denom);\n+}\n+\n+} /* namespace */\n+\n Agc::Agc()\n {\n }\n@@ -158,41 +197,14 @@ void Agc::process(IPAContext &context,\n \t\treturn;\n \t}\n \n-\t/*\n-\t * Calculate Mean Sample Value (MSV) according to formula from:\n-\t * https://www.araa.asn.au/acra/acra2007/papers/paper84final.pdf\n-\t */\n-\tconst auto &histogram = stats->yHistogram;\n-\tconst unsigned int blackLevelHistIdx =\n-\t\tcontext.activeState.blc.level / (256 / SwIspStats::kYHistogramSize);\n-\tconst unsigned int histogramSize =\n-\t\tSwIspStats::kYHistogramSize - blackLevelHistIdx;\n-\tconst unsigned int yHistValsPerBin = histogramSize / kExposureBinsCount;\n-\tconst unsigned int yHistValsPerBinMod =\n-\t\thistogramSize / (histogramSize % kExposureBinsCount + 1);\n-\tint exposureBins[kExposureBinsCount] = {};\n-\tunsigned int denom = 0;\n-\tunsigned int num = 0;\n-\n-\tif (yHistValsPerBin == 0) {\n+\tauto exposureMSV = calculateMSV(stats->yHistogram, context.activeState.blc.level);\n+\tif (!exposureMSV) {\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-\t}\n-\n-\tfor (unsigned int i = 0; i < kExposureBinsCount; i++) {\n-\t\tLOG(IPASoftExposure, Debug) << i << \": \" << exposureBins[i];\n-\t\tdenom += exposureBins[i];\n-\t\tnum += exposureBins[i] * (i + 1);\n-\t}\n-\n-\tfloat exposureMSV = (denom == 0 ? 0 : static_cast<float>(num) / denom);\n-\tupdateExposure(context, frameContext, exposureMSV);\n+\tupdateExposure(context, frameContext, *exposureMSV);\n }\n \n REGISTER_IPA_ALGORITHM(Agc, \"Agc\")\n", "prefixes": [ "RFC", "v2", "33/43" ] }