lsc.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2026 Ideas on Board Oy
 *
 * libIPA Lsc algorithm
 */
 
#pragma once
 
#include <memory>
#include <span>
#include <vector>
 
#include <libcamera/controls.h>
#include <libcamera/geometry.h>
 
#include "libcamera/internal/value_node.h"
 
#include "interpolator.h"
#include "lsc_base.h"
 
namespace libcamera {
 
namespace ipa {
 
namespace lsc {
 
struct ActiveState {
    bool enabled;
};
 
struct FrameContext {
    bool enabled;
    bool update;
};
 
template<typename T>
using Components = std::map<std::string, std::vector<T>, std::less<>>;
 
template<typename T>
using ComponentsMap = std::map<unsigned int, Components<T>>;
 
} /* namespace lsc */
 
#ifndef __DOXYGEN__
template<>
void Interpolator<lsc::Components<uint16_t>>::
    interpolate(const lsc::Components<uint16_t> &a,
            const lsc::Components<uint16_t> &b,
            lsc::Components<uint16_t> &dest,
            double lambda);
 
template<>
void Interpolator<lsc::Components<uint8_t>>::
    interpolate(const lsc::Components<uint8_t> &a,
            const lsc::Components<uint8_t> &b,
            lsc::Components<uint8_t> &dest,
            double lambda);
#endif /* __DOXYGEN__ */
 
class LscAlgorithmBase
{
public:
    int init(const ValueNode &tuningData, ControlInfoMap::Map &controls,
         const LscDescriptor &descriptor);
 
    void queueRequest(lsc::ActiveState &state, lsc::FrameContext &context,
              const ControlList &controls);
    void process(lsc::FrameContext &context, ControlList &metadata);
 
protected:
    LscAlgorithmBase() = default;
 
    std::unique_ptr<LscImplementation> impl_;
    bool polynomial_;
};
 
template<typename U>
class LscAlgorithm : public LscAlgorithmBase
{
private:
    using Components = lsc::Components<typename U::QuantizedType>;
    using ComponentsMap = lsc::ComponentsMap<typename U::QuantizedType>;
 
public:
    LscAlgorithm() = default;
 
    int configure(lsc::ActiveState &state, const Rectangle &analogCrop,
              std::span<const double> xPos,
              std::span<const double> yPos)
    {
        LscImplementation::ComponentsMap data =
            impl_->sampleForCrop(analogCrop, xPos, yPos);
 
        ComponentsMap lscData;
        for (const auto &[t, c] : data) {
            Components &comp = lscData[t];
 
            for (const auto &[k, gains] : c) {
                auto &quantizedGains = comp[k];
                quantizedGains.reserve(gains.size());
 
                for (const float &gain : gains) {
                    /*
                     * Tabular LSC tables already store
                     * quantized values.
                     */
                    if (polynomial_)
                        quantizedGains.push_back(U(gain).quantized());
                    else
                        quantizedGains.push_back(gain);
                }
            }
        }
 
        sets_.setData(std::move(lscData));
        state.enabled = true;
 
        return 0;
    }
 
    const Components &interpolateComponents(unsigned int ct)
    {
        return sets_.getInterpolated(ct);
    }
 
    const ComponentsMap &getComponents() const
    {
        return sets_.data();
    }
 
private:
    Interpolator<Components> sets_;
};
 
} /* namespace ipa */
 
} /* namespace libcamera */