Files
lms/src/libs/services/recommendation/impl/audio-similarity/NearDuplicateEmbeddingConstraint.hpp
T

69 lines
2.4 KiB
C++

/*
* Copyright (C) 2026 Emeric Poupon
*
* This file is part of LMS.
*
* LMS is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* LMS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with LMS. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <unordered_map>
#include "database/objects/TrackId.hpp"
#include "math/NormalizedCosineDistance.hpp"
#include "math/Vector.hpp"
#include "track-selection-constraints/ITrackCandidateHardConstraint.hpp"
#include "Types.hpp"
namespace lms::recommendation
{
// Rejects any candidate whose embedding is closer than 'threshold' to any already-selected
// track's embedding — catches the same recording appearing in multiple compilations.
template<std::size_t ReducedDimCount>
class NearDuplicateEmbeddingConstraint : public ITrackCandidateHardConstraint
{
public:
using ReducedVector = math::Vector<ReducedDimCount, FloatType>;
using TrackVectorMap = std::unordered_map<db::TrackId, const ReducedVector*>;
NearDuplicateEmbeddingConstraint(const TrackVectorMap& trackVectors, float threshold)
: _trackVectors{ trackVectors }
, _threshold{ threshold }
{
}
bool rejects(const TrackCandidateContext& context) const override
{
const auto itCandidate{ _trackVectors.find(context.candidateTrackId) };
if (itCandidate == _trackVectors.cend())
return false;
const math::NormalizedCosineDistance distFunc{ *itCandidate->second };
for (const db::TrackId selectedId : context.selectedTracks)
{
const auto it{ _trackVectors.find(selectedId) };
if (it != _trackVectors.cend() && distFunc(*it->second) < _threshold)
return true;
}
return false;
}
private:
const TrackVectorMap& _trackVectors;
float _threshold;
};
} // namespace lms::recommendation