From patchwork Wed Jan 21 17:37:20 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 25908 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 8978ABDCBF for ; Wed, 21 Jan 2026 17:37:47 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 5D0E361FE2; Wed, 21 Jan 2026 18:37:46 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="qOxu/O5l"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 6947361FBB for ; Wed, 21 Jan 2026 18:37:42 +0100 (CET) Received: from Monstersaurus.hippo-penny.ts.net (cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 2DD1CE0D; Wed, 21 Jan 2026 18:37:10 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1769017030; bh=6MjPqbKsBDFtbPAC6+InDl9o6WOtNPotWwZjBwLRD1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qOxu/O5lyHtS7CbBj7as5dN3vUEB9QeDQDGmGrqLuG1H1ZWam2hYC4ZaXR7ONs/x8 VC14JGQrGe5y7PInv1P9r6xHGMeZHnHriRIH/2YWnfgJ4RXCNPsKZVYrM6Wq9eu9uI Lh9umbqDb2QU6L36rd894cGJ84dZHKdhKSgo5LnE= From: Kieran Bingham To: libcamera devel Cc: Kieran Bingham , =?utf-8?q?Barnab?= =?utf-8?b?w6FzIFDFkWN6ZQ==?= , Isaac Scott Subject: [PATCH v6 01/16] ipa: libipa: Provide a Quantized data type support Date: Wed, 21 Jan 2026 17:37:20 +0000 Message-ID: <20260121173737.376113-2-kieran.bingham@ideasonboard.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121173737.376113-1-kieran.bingham@ideasonboard.com> References: <20260121173737.376113-1-kieran.bingham@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Frequently when handling data in IPA components we must convert and store user interface values which may be floating point values, and perform a specific operation or conversion to quantize this to a hardware value. This value may be to a fixed point type, or more custom code mappings, but in either case it is important to contain both the required hardware value, with its effective quantized value. Provide a new storage type 'Quantized' which can be defined based on a set of type specific Traits to perform the conversions between floats and the underlying hardware type. Reviewed-by: Barnabás Pőcze Reviewed-by: Isaac Scott Signed-off-by: Kieran Bingham --- v3: - adapt string format to [0xff:1.99] style instead of Q:0xff V:1.99 - Clean up comments and copyright - Remove private initialisers - already handled by constructors - Change quantized_type to QuantizedType v5: - introduce operator<<(std::ostream &out, const Quantized &q) - Remove unused iomanip and stdint.h from includes Signed-off-by: Kieran Bingham --- src/ipa/libipa/meson.build | 2 + src/ipa/libipa/quantized.cpp | 135 +++++++++++++++++++++++++++++++++++ src/ipa/libipa/quantized.h | 75 +++++++++++++++++++ 3 files changed, 212 insertions(+) create mode 100644 src/ipa/libipa/quantized.cpp create mode 100644 src/ipa/libipa/quantized.h diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build index 7202df869c2f..963c5ee73063 100644 --- a/src/ipa/libipa/meson.build +++ b/src/ipa/libipa/meson.build @@ -17,6 +17,7 @@ libipa_headers = files([ 'lux.h', 'module.h', 'pwl.h', + 'quantized.h', 'v4l2_params.h', ]) @@ -37,6 +38,7 @@ libipa_sources = files([ 'lux.cpp', 'module.cpp', 'pwl.cpp', + 'quantized.cpp', 'v4l2_params.cpp', ]) diff --git a/src/ipa/libipa/quantized.cpp b/src/ipa/libipa/quantized.cpp new file mode 100644 index 000000000000..06143a97ab3e --- /dev/null +++ b/src/ipa/libipa/quantized.cpp @@ -0,0 +1,135 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2025, Ideas On Board Oy + * + * Helper class to manage conversions between floating point types and quantized + * storage and representation of those values. + */ + +#include "quantized.h" + +/** + * \file quantized.h + * \brief Quantized storage and Quantizer representations + */ + +namespace libcamera { + +namespace ipa { + +/** + * \struct libcamera::ipa::Quantized + * \brief Wrapper that stores a value in both quantized and floating-point form + * \tparam Traits The traits class defining the quantization behaviour + * + * The Quantized struct template provides a thin wrapper around a quantized + * representation of a floating-point value. It uses a traits type \a Traits + * to define the conversion policy between the floating-point domain and the + * quantized integer domain. + * + * Each Quantized instance maintains two synchronized members: + * - the quantized integer representation, and + * - the corresponding floating-point value. + * + * The traits type defines: + * - the integer storage type used for quantization, + * - the static conversion functions \c fromFloat() and \c toFloat(), and + * - optional metadata such as value ranges. + * + * Quantized provides convenient constructors and assignment operators from + * either representation, as well as comparison and string formatting utilities. + */ + +/** + * \typedef Quantized::TraitsType + * \brief The traits policy type defining the quantization behaviour + * + * Exposes the associated traits type used by this Quantized instance. + * This allows external code to refer to constants or metadata defined in + * the traits, such as \c TraitsType::min or \c TraitsType::max. + */ + +/** + * \typedef Quantized::QuantizedType + * \brief The integer type used for the quantized representation + * + * This alias corresponds to \c TraitsType::QuantizedType, as defined by + * the traits class. + */ + +/** + * \fn Quantized::Quantized(float x) + * \brief Construct a Quantized value from a floating-point number + * \param[in] x The floating-point value to be quantized + * + * Converts the floating-point input \a x to its quantized integer + * representation using the associated traits policy, and initializes + * both the quantized and floating-point members. + */ + +/** + * \fn Quantized::Quantized(QuantizedType x) + * \brief Construct a Quantized value from an existing quantized integer + * \param[in] x The quantized integer value + * + * Converts the quantized integer \a x to its corresponding floating-point + * value using the traits policy, and initializes both internal members. + */ + +/** + * \fn Quantized::operator=(float x) + * \brief Assign a floating-point value to the Quantized object + * \param[in] x The floating-point value to assign + * \return A reference to the updated Quantized object + * + * Converts the floating-point value \a x to its quantized integer + * representation using the traits policy and updates both members. + */ + +/** + * \fn Quantized::operator=(QuantizedType x) + * \brief Assign a quantized integer value to the Quantized object + * \param[in] x The quantized integer value to assign + * \return A reference to the updated Quantized object + * + * Converts the quantized integer \a x to its corresponding floating-point + * value using the traits policy and updates both members. + */ + +/** + * \fn Quantized::value() const noexcept + * \brief Retrieve the floating-point representation + * \return The floating-point value corresponding to the quantized value + */ + +/** + * \fn Quantized::quantized() const noexcept + * \brief Retrieve the quantized integer representation + * \return The quantized integer value + */ + +/** + * \fn Quantized::operator==(const Quantized &other) const noexcept + * \brief Compare two Quantized objects for equality + * \param[in] other The other Quantized object to compare against + * \return True if both objects have the same quantized integer value + */ + +/** + * \fn Quantized::operator!=(const Quantized &other) const noexcept + * \brief Compare two Quantized objects for inequality + * \param[in] other The other Quantized object to compare against + * \return True if the quantized integer values differ + */ + +/** + * \fn std::ostream &Quantized::operator<<(std::ostream &out, const Quantized &q) + * \brief Insert a text representation of a Quantized into an output stream + * \param[in] out The output stream + * \param[in] q The Quantized + * \return The output stream \a out + */ + +} /* namespace ipa */ + +} /* namespace libcamera */ diff --git a/src/ipa/libipa/quantized.h b/src/ipa/libipa/quantized.h new file mode 100644 index 000000000000..0b2f7148c821 --- /dev/null +++ b/src/ipa/libipa/quantized.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2025, Ideas On Board Oy + * + * Helper class to manage conversions between floating point types and quantized + * storage and representation of those values. + */ + +#pragma once + +#include +#include + +#include + +namespace libcamera { + +namespace ipa { + +template +struct Quantized { + using TraitsType = Traits; + using QuantizedType = typename Traits::QuantizedType; + static_assert(std::is_arithmetic_v, + "Quantized: QuantizedType must be arithmetic"); + + Quantized() + : Quantized(0.0f) {} + Quantized(float x) { *this = x; } + Quantized(QuantizedType x) { *this = x; } + + Quantized &operator=(float x) + { + quantized_ = Traits::fromFloat(x); + value_ = Traits::toFloat(quantized_); + return *this; + } + + Quantized &operator=(QuantizedType x) + { + value_ = Traits::toFloat(x); + quantized_ = x; + return *this; + } + + float value() const noexcept { return value_; } + QuantizedType quantized() const noexcept { return quantized_; } + + bool operator==(const Quantized &other) const noexcept + { + return quantized_ == other.quantized_; + } + + bool operator!=(const Quantized &other) const noexcept + { + return !(*this == other); + } + + friend std::ostream &operator<<(std::ostream &out, + const Quantized &q) + { + out << "[" << utils::hex(q.quantized()) + << ":" << q.value() << "]"; + + return out; + } + +private: + QuantizedType quantized_; + float value_; +}; + +} /* namespace ipa */ + +} /* namespace libcamera */