{"id":26198,"url":"https://patchwork.libcamera.org/api/patches/26198/?format=json","web_url":"https://patchwork.libcamera.org/patch/26198/","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":"<20260219-kbingham-quantizers-v8-1-2b6ff68ead26@ideasonboard.com>","date":"2026-02-19T15:05:02","name":"[v8,01/15] ipa: libipa: Provide a Quantized data type support","commit_ref":"be64005a8e6b8dd3b523c7dc249f54220dd2ad6c","pull_url":null,"state":"accepted","archived":false,"hash":"fb86882622229adf77ed6ba81261f282c7ced7d4","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/?format=json","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/26198/mbox/","series":[{"id":5802,"url":"https://patchwork.libcamera.org/api/series/5802/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5802","date":"2026-02-19T15:05:01","name":"libipa: Introduce a Quantized type","version":8,"mbox":"https://patchwork.libcamera.org/series/5802/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/26198/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/26198/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 94B2AC0DA4\n\tfor ;\n\tThu, 19 Feb 2026 15:05:17 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id AB2C562274;\n\tThu, 19 Feb 2026 16:05:12 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 14B4762251\n\tfor ;\n\tThu, 19 Feb 2026 16:05:09 +0100 (CET)","from ping.linuxembedded.co.uk\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 73D8855C;\n\tThu, 19 Feb 2026 16:04:15 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"MwSoJGWV\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1771513455;\n\tbh=dBHuLUuIc6+R/8QxjRevUxGQdZjVWnIPBGkj+L2BXAI=;\n\th=From:Date:Subject:References:In-Reply-To:To:Cc:From;\n\tb=MwSoJGWVGWA1q0kRWWBOhuaBoNYS4PIVrmLyal9E3HgCGYWp/g6Axkr3dScfEf9Xg\n\twJMcnvgtWejCfRxSBqUXXH3cUsTSdyvuKO5uH2IVtZZZGCCf5/OzXGTSY4923frgzN\n\tGz1p3xf3ktqkBZaKpJ8Lj1LxLBrqk2/5+S1vOZ7g=","From":"Kieran Bingham ","Date":"Thu, 19 Feb 2026 15:05:02 +0000","Subject":"[PATCH v8 01/15] ipa: libipa: Provide a Quantized data type support","MIME-Version":"1.0","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"8bit","Message-Id":"<20260219-kbingham-quantizers-v8-1-2b6ff68ead26@ideasonboard.com>","References":"<20260219-kbingham-quantizers-v8-0-2b6ff68ead26@ideasonboard.com>","In-Reply-To":"<20260219-kbingham-quantizers-v8-0-2b6ff68ead26@ideasonboard.com>","To":"libcamera-devel@lists.libcamera.org","Cc":"Kieran Bingham , =?utf-8?q?Barnab?=\n\t=?utf-8?b?w6FzIFDFkWN6ZQ==?= ,\n\tIsaac Scott , \n\tPaul Elder ","X-Mailer":"b4 0.14.3","X-Developer-Signature":"v=1; a=ed25519-sha256; t=1771513507; l=8394;\n\ti=kieran.bingham@ideasonboard.com; s=20260207;\n\th=from:subject:message-id; \n\tbh=dBHuLUuIc6+R/8QxjRevUxGQdZjVWnIPBGkj+L2BXAI=;\n\tb=bE25xL25qBG+owLZzMU78RY9GnL4aO6sXsVIKksP9C+cTgWMxldDagwXLKurn9gc8WGNxSLc3\n\tD8En2am2wXMBd+vPyh0GNUe7FJGHYz95QvhCpNSo48jI1pwds7TDf4x","X-Developer-Key":"i=kieran.bingham@ideasonboard.com; a=ed25519;\n\tpk=FVXKN7YuwHc6UtbRUeTMAmranfsQomA+vnilfglWdaY=","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":"Frequently when handling data in IPA components we must convert and\nstore user interface values which may be floating point values, and\nperform a specific operation or conversion to quantize this to a\nhardware value.\n\nThis value may be to a fixed point type, or more custom code mappings,\nbut in either case it is important to contain both the required hardware\nvalue, with its effective quantized value.\n\nProvide a new storage type 'Quantized' which can be defined based on a\nset of type specific Traits to perform the conversions between floats\nand the underlying hardware type.\n\nReviewed-by: Barnabás Pőcze \nReviewed-by: Isaac Scott \nReviewed-by: Paul Elder \nSigned-off-by: Kieran Bingham \n\n---\n\nv8:\n - Remove noexcept\n---\n src/ipa/libipa/meson.build | 2 +\n src/ipa/libipa/quantized.cpp | 135 +++++++++++++++++++++++++++++++++++++++++++\n src/ipa/libipa/quantized.h | 75 ++++++++++++++++++++++++\n 3 files changed, 212 insertions(+)","diff":"diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build\nindex 7202df869c2f..963c5ee73063 100644\n--- a/src/ipa/libipa/meson.build\n+++ b/src/ipa/libipa/meson.build\n@@ -17,6 +17,7 @@ libipa_headers = files([\n 'lux.h',\n 'module.h',\n 'pwl.h',\n+ 'quantized.h',\n 'v4l2_params.h',\n ])\n \n@@ -37,6 +38,7 @@ libipa_sources = files([\n 'lux.cpp',\n 'module.cpp',\n 'pwl.cpp',\n+ 'quantized.cpp',\n 'v4l2_params.cpp',\n ])\n \ndiff --git a/src/ipa/libipa/quantized.cpp b/src/ipa/libipa/quantized.cpp\nnew file mode 100644\nindex 000000000000..06143a97ab3e\n--- /dev/null\n+++ b/src/ipa/libipa/quantized.cpp\n@@ -0,0 +1,135 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2025, Ideas On Board Oy\n+ *\n+ * Helper class to manage conversions between floating point types and quantized\n+ * storage and representation of those values.\n+ */\n+\n+#include \"quantized.h\"\n+\n+/**\n+ * \\file quantized.h\n+ * \\brief Quantized storage and Quantizer representations\n+ */\n+\n+namespace libcamera {\n+\n+namespace ipa {\n+\n+/**\n+ * \\struct libcamera::ipa::Quantized\n+ * \\brief Wrapper that stores a value in both quantized and floating-point form\n+ * \\tparam Traits The traits class defining the quantization behaviour\n+ *\n+ * The Quantized struct template provides a thin wrapper around a quantized\n+ * representation of a floating-point value. It uses a traits type \\a Traits\n+ * to define the conversion policy between the floating-point domain and the\n+ * quantized integer domain.\n+ *\n+ * Each Quantized instance maintains two synchronized members:\n+ * - the quantized integer representation, and\n+ * - the corresponding floating-point value.\n+ *\n+ * The traits type defines:\n+ * - the integer storage type used for quantization,\n+ * - the static conversion functions \\c fromFloat() and \\c toFloat(), and\n+ * - optional metadata such as value ranges.\n+ *\n+ * Quantized provides convenient constructors and assignment operators from\n+ * either representation, as well as comparison and string formatting utilities.\n+ */\n+\n+/**\n+ * \\typedef Quantized::TraitsType\n+ * \\brief The traits policy type defining the quantization behaviour\n+ *\n+ * Exposes the associated traits type used by this Quantized instance.\n+ * This allows external code to refer to constants or metadata defined in\n+ * the traits, such as \\c TraitsType::min or \\c TraitsType::max.\n+ */\n+\n+/**\n+ * \\typedef Quantized::QuantizedType\n+ * \\brief The integer type used for the quantized representation\n+ *\n+ * This alias corresponds to \\c TraitsType::QuantizedType, as defined by\n+ * the traits class.\n+ */\n+\n+/**\n+ * \\fn Quantized::Quantized(float x)\n+ * \\brief Construct a Quantized value from a floating-point number\n+ * \\param[in] x The floating-point value to be quantized\n+ *\n+ * Converts the floating-point input \\a x to its quantized integer\n+ * representation using the associated traits policy, and initializes\n+ * both the quantized and floating-point members.\n+ */\n+\n+/**\n+ * \\fn Quantized::Quantized(QuantizedType x)\n+ * \\brief Construct a Quantized value from an existing quantized integer\n+ * \\param[in] x The quantized integer value\n+ *\n+ * Converts the quantized integer \\a x to its corresponding floating-point\n+ * value using the traits policy, and initializes both internal members.\n+ */\n+\n+/**\n+ * \\fn Quantized::operator=(float x)\n+ * \\brief Assign a floating-point value to the Quantized object\n+ * \\param[in] x The floating-point value to assign\n+ * \\return A reference to the updated Quantized object\n+ *\n+ * Converts the floating-point value \\a x to its quantized integer\n+ * representation using the traits policy and updates both members.\n+ */\n+\n+/**\n+ * \\fn Quantized::operator=(QuantizedType x)\n+ * \\brief Assign a quantized integer value to the Quantized object\n+ * \\param[in] x The quantized integer value to assign\n+ * \\return A reference to the updated Quantized object\n+ *\n+ * Converts the quantized integer \\a x to its corresponding floating-point\n+ * value using the traits policy and updates both members.\n+ */\n+\n+/**\n+ * \\fn Quantized::value() const noexcept\n+ * \\brief Retrieve the floating-point representation\n+ * \\return The floating-point value corresponding to the quantized value\n+ */\n+\n+/**\n+ * \\fn Quantized::quantized() const noexcept\n+ * \\brief Retrieve the quantized integer representation\n+ * \\return The quantized integer value\n+ */\n+\n+/**\n+ * \\fn Quantized::operator==(const Quantized &other) const noexcept\n+ * \\brief Compare two Quantized objects for equality\n+ * \\param[in] other The other Quantized object to compare against\n+ * \\return True if both objects have the same quantized integer value\n+ */\n+\n+/**\n+ * \\fn Quantized::operator!=(const Quantized &other) const noexcept\n+ * \\brief Compare two Quantized objects for inequality\n+ * \\param[in] other The other Quantized object to compare against\n+ * \\return True if the quantized integer values differ\n+ */\n+\n+/**\n+ * \\fn std::ostream &Quantized::operator<<(std::ostream &out, const Quantized &q)\n+ * \\brief Insert a text representation of a Quantized into an output stream\n+ * \\param[in] out The output stream\n+ * \\param[in] q The Quantized\n+ * \\return The output stream \\a out\n+ */\n+\n+} /* namespace ipa */\n+\n+} /* namespace libcamera */\ndiff --git a/src/ipa/libipa/quantized.h b/src/ipa/libipa/quantized.h\nnew file mode 100644\nindex 000000000000..6bd196c7d9f2\n--- /dev/null\n+++ b/src/ipa/libipa/quantized.h\n@@ -0,0 +1,75 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2025, Ideas On Board Oy\n+ *\n+ * Helper class to manage conversions between floating point types and quantized\n+ * storage and representation of those values.\n+ */\n+\n+#pragma once\n+\n+#include \n+#include \n+\n+#include \n+\n+namespace libcamera {\n+\n+namespace ipa {\n+\n+template\n+struct Quantized {\n+\tusing TraitsType = Traits;\n+\tusing QuantizedType = typename Traits::QuantizedType;\n+\tstatic_assert(std::is_arithmetic_v,\n+\t\t \"Quantized: QuantizedType must be arithmetic\");\n+\n+\tQuantized()\n+\t\t: Quantized(0.0f) {}\n+\tQuantized(float x) { *this = x; }\n+\tQuantized(QuantizedType x) { *this = x; }\n+\n+\tQuantized &operator=(float x)\n+\t{\n+\t\tquantized_ = Traits::fromFloat(x);\n+\t\tvalue_ = Traits::toFloat(quantized_);\n+\t\treturn *this;\n+\t}\n+\n+\tQuantized &operator=(QuantizedType x)\n+\t{\n+\t\tvalue_ = Traits::toFloat(x);\n+\t\tquantized_ = x;\n+\t\treturn *this;\n+\t}\n+\n+\tfloat value() const { return value_; }\n+\tQuantizedType quantized() const { return quantized_; }\n+\n+\tbool operator==(const Quantized &other) const\n+\t{\n+\t\treturn quantized_ == other.quantized_;\n+\t}\n+\n+\tbool operator!=(const Quantized &other) const\n+\t{\n+\t\treturn !(*this == other);\n+\t}\n+\n+\tfriend std::ostream &operator<<(std::ostream &out,\n+\t\t\t\t\tconst Quantized &q)\n+\t{\n+\t\tout << \"[\" << utils::hex(q.quantized())\n+\t\t << \":\" << q.value() << \"]\";\n+\n+\t\treturn out;\n+\t}\n+\n+private:\n+\tQuantizedType quantized_;\n+\tfloat value_;\n+};\n+\n+} /* namespace ipa */\n+\n+} /* namespace libcamera */\n","prefixes":["v8","01/15"]}