path: root/utils/sofa-info.cpp

/*
 * SOFA info utility for inspecting SOFA file metrics and determining HRTF
 * utility compatible layouts.
 *
 * Copyright (C) 2018-2019  Christopher Fitzgerald
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Or visit:  http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

#include <stdio.h>

#include <algorithm>
#include <array>
#include <cmath>
#include <memory>
#include <vector>

#include <mysofa.h>

#include "win_main_utf8.h"


using uint = unsigned int;
using double3 = std::array<double,3>;

struct MySofaDeleter {
    void operator()(MYSOFA_HRTF *sofa) { mysofa_free(sofa); }
};
using MySofaHrtfPtr = std::unique_ptr<MYSOFA_HRTF,MySofaDeleter>;

// Per-field measurement info.
struct HrirFdT {
    double mDistance{0.0};
    uint mEvCount{0u};
    uint mEvStart{0u};
    std::vector<uint> mAzCounts;
};

static const char *SofaErrorStr(int err)
{
    switch(err)
    {
    case MYSOFA_OK: return "OK";
    case MYSOFA_INVALID_FORMAT: return "Invalid format";
    case MYSOFA_UNSUPPORTED_FORMAT: return "Unsupported format";
    case MYSOFA_INTERNAL_ERROR: return "Internal error";
    case MYSOFA_NO_MEMORY: return "Out of memory";
    case MYSOFA_READ_ERROR: return "Read error";
    }
    return "Unknown";
}

static void PrintSofaAttributes(const char *prefix, struct MYSOFA_ATTRIBUTE *attribute)
{
    while(attribute)
    {
        fprintf(stdout, "%s.%s: %s\n", prefix, attribute->name, attribute->value);
        attribute = attribute->next;
    }
}

static void PrintSofaArray(const char *prefix, struct MYSOFA_ARRAY *array)
{
    PrintSofaAttributes(prefix, array->attributes);

    for(uint i{0u};i < array->elements;i++)
        fprintf(stdout, "%s[%u]: %.6f\n", prefix, i, array->values[i]);
}

/* Produces a sorted array of unique elements from a particular axis of the
 * triplets array.  The filters are used to focus on particular coordinates
 * of other axes as necessary.  The epsilons are used to constrain the
 * equality of unique elements.
 */
static std::vector<double> GetUniquelySortedElems(const uint m, const double3 *aers,
    const uint axis, const double *const (&filters)[3], const double (&epsilons)[3])
{
    std::vector<double> elems;
    for(uint i{0u};i < m;++i)
    {
        const double elem{aers[i][axis]};

        uint j;
        for(j = 0;j < 3;j++)
        {
            if(filters[j] && std::abs(aers[i][j] - *filters[j]) > epsilons[j])
                break;
        }
        if(j < 3)
            continue;

        auto iter = elems.begin();
        for(;iter != elems.end();++iter)
        {
            const double delta{elem - *iter};
            if(delta > epsilons[axis]) continue;
            if(delta >= -epsilons[axis]) break;

            iter = elems.emplace(iter, elem);
            break;
        }
        if(iter == elems.end())
            elems.emplace_back(elem);
    }
    return elems;
}

/* Given a list of azimuths, this will produce the smallest step size that can
 * uniformly cover the list. Ideally this will be over half, but in degenerate
 * cases this can fall to a minimum of 5 (the lower limit).
 */
static double GetUniformAzimStep(const double epsilon, const size_t m, const double *elems)
{
    if(m < 5) return 0.0;

    /* Get the maximum count possible (limit to 255), given the first two
     * elements. It would be impossible to have more than this since the first
     * element must be included.
     */
    uint count{static_cast<uint>(std::ceil(360.0 / (elems[1]-elems[0])))};
    count = std::min(count, 255u);

    for(;count >= 5;--count)
    {
        /* Given the stepping value for this number of elements, check each
         * multiple to ensure there's a matching element.
         */
        const double step{360.0 / count};
        bool good{true};
        size_t idx{1u};
        for(uint mult{1u};mult < count && good;++mult)
        {
            const double target{step*mult + elems[0]};
            while(idx < m && target-elems[idx] > epsilon)
                ++idx;
            good &= (idx < m) && !(std::abs(target-elems[idx++]) > epsilon);
        }
        if(good)
            return step;
    }
    return 0.0;
}

/* Given a list of elevations, this will produce the smallest step size that
 * can uniformly cover the list. Ideally this will be over half, but in
 * degenerate cases this can fall to a minimum of 5 (the lower limit).
 */
static double GetUniformElevStep(const double epsilon, const size_t m, const double *elems)
{
    if(m < 5) return 0.0;

    uint count{static_cast<uint>(std::ceil(180.0 / (elems[1]-elems[0])))};
    count = std::min(count, 255u);

    for(;count >= 5;--count)
    {
        const double step{180.0 / count};
        bool good{true};
        size_t idx{1u};
        /* Elevations don't need to match all multiples if there's not enough
         * elements to check. Missing elevations can be synthesized.
         */
        for(uint mult{1u};mult <= count && idx < m && good;++mult)
        {
            const double target{step*mult + elems[0]};
            while(idx < m && target-elems[idx] > epsilon)
                ++idx;
            good &= !(idx < m) || !(std::abs(target-elems[idx++]) > epsilon);
        }
        if(good)
            return step;
    }
    return 0.0;
}

/* Attempts to produce a compatible layout.  Most data sets tend to be
 * uniform and have the same major axis as used by OpenAL Soft's HRTF model.
 * This will remove outliers and produce a maximally dense layout when
 * possible.  Those sets that contain purely random measurements or use
 * different major axes will fail.
 */
static void PrintCompatibleLayout(const uint m, const float *xyzs)
{
    fprintf(stdout, "\n");

    auto aers = std::vector<double3>(m, double3{});
    for(uint i{0u};i < m;++i)
    {
        float aer[3]{xyzs[i*3], xyzs[i*3 + 1], xyzs[i*3 + 2]};
        mysofa_c2s(&aer[0]);
        aers[i][0] = aer[0];
        aers[i][1] = aer[1];
        aers[i][2] = aer[2];
    }

    auto radii = GetUniquelySortedElems(m, aers.data(), 2, {}, {0.1, 0.1, 0.001});
    if(radii.size() > (m / 3))
    {
        fprintf(stdout, "Incompatible layout (inumerable radii).\n");
        return;
    }

    auto fds = std::vector<HrirFdT>(radii.size());
    for(size_t fi{0u};fi < radii.size();fi++)
        fds[fi].mDistance = radii[fi];

    for(uint fi{0u};fi < fds.size();)
    {
        const double dist{fds[fi].mDistance};
        auto elevs = GetUniquelySortedElems(m, aers.data(), 1, {nullptr, nullptr, &dist},
            {0.1, 0.1, 0.001});

        /* Remove elevations that don't have a valid set of azimuths. */
        auto invalid_elev = [&dist,&aers,m](const double ev) -> bool
        {
            auto azim = GetUniquelySortedElems(m, aers.data(), 0, {nullptr, &ev, &dist},
                {0.1, 0.1, 0.001});

            if(std::abs(90.0 - std::abs(ev)) < 0.1)
                return azim.size() != 1;
            if(azim.empty() || !(std::abs(azim[0]) < 0.1))
                return true;
            return GetUniformAzimStep(0.1, azim.size(), azim.data()) <= 0.0;
        };
        elevs.erase(std::remove_if(elevs.begin(), elevs.end(), invalid_elev), elevs.end());

        /* Reverse the elevations so it increments starting with -90 (flipped
         * from +90). This makes it easier to work out a proper stepping value.
         */
        std::reverse(elevs.begin(), elevs.end());
        for(auto &ev : elevs) ev *= -1.0;

        double step{GetUniformElevStep(0.1, elevs.size(), elevs.data())};
        if(step <= 0.0)
        {
            fprintf(stdout, "Non-uniform elevations on field distance %f.\n", dist);
            fds.erase(fds.begin() + static_cast<ptrdiff_t>(fi));
            continue;
        }

        /* Re-reverse the elevations to restore the correct order. */
        for(auto &ev : elevs) ev *= -1.0;
        std::reverse(elevs.begin(), elevs.end());

        uint evStart{0u};
        for(uint ei{0u};ei < elevs.size();ei++)
        {
            if(!(elevs[ei] < 0.0))
            {
                fprintf(stdout, "Too many missing elevations on field distance %f.\n", dist);
                return;
            }

            double eif{(90.0+elevs[ei]) / step};
            const double ev_start{std::round(eif)};

            if(std::abs(eif - ev_start) < (0.1/step))
            {
                evStart = static_cast<uint>(ev_start);
                break;
            }
        }

        const auto evCount = static_cast<uint>(std::round(180.0 / step)) + 1;
        if(evCount < 5)
        {
            fprintf(stdout, "Too few uniform elevations on field distance %f.\n", dist);
            fds.erase(fds.begin() + static_cast<ptrdiff_t>(fi));
            continue;
        }

        fds[fi].mEvCount = evCount;
        fds[fi].mEvStart = evStart;
        fds[fi].mAzCounts.resize(evCount);
        auto &azCounts = fds[fi].mAzCounts;

        for(uint ei{evStart};ei < evCount;ei++)
        {
            double ev{-90.0 + ei*180.0/(evCount - 1)};
            auto azims = GetUniquelySortedElems(m, aers.data(), 0, { nullptr, &ev, &dist },
                { 0.1, 0.1, 0.001 });

            if(ei == 0 || ei == (evCount-1))
            {
                if(azims.size() != 1)
                {
                    fprintf(stdout, "Non-singular poles on field distance %f.\n", dist);
                    return;
                }
                azCounts[ei] = 1;
            }
            else
            {
                step = GetUniformAzimStep(0.1, azims.size(), azims.data());
                if(step <= 0.0)
                {
                    fprintf(stdout, "Non-uniform azimuths on elevation %f, field distance %f.\n",
                        ev, dist);
                    return;
                }
                azCounts[ei] = static_cast<uint>(std::round(360.0f / step));
            }
        }

        for(uint ei{0u};ei < evStart;ei++)
            azCounts[ei] = azCounts[evCount - ei - 1];
        ++fi;
    }
    if(fds.empty())
    {
        fprintf(stdout, "No compatible field layouts in SOFA file.\n");
        return;
    }

    fprintf(stdout, "Compatible Layout:\n\ndistance = %.3f", fds[0].mDistance);
    for(size_t fi{1u};fi < fds.size();fi++)
        fprintf(stdout, ", %.3f", fds[fi].mDistance);

    fprintf(stdout, "\nazimuths = ");
    for(size_t fi{0u};fi < fds.size();fi++)
    {
        for(uint ei{0u};ei < fds[fi].mEvCount;ei++)
            fprintf(stdout, "%d%s", fds[fi].mAzCounts[ei],
                (ei < (fds[fi].mEvCount - 1)) ? ", " :
                (fi < (fds.size() - 1)) ? ";\n           " : "\n");
    }
}

// Load and inspect the given SOFA file.
static void SofaInfo(const char *filename)
{
    int err;
    MySofaHrtfPtr sofa{mysofa_load(filename, &err)};
    if(!sofa)
    {
        fprintf(stdout, "Error: Could not load source file '%s'.\n", filename);
        return;
    }

    /* NOTE: Some valid SOFA files are failing this check. */
    err = mysofa_check(sofa.get());
    if(err != MYSOFA_OK)
        fprintf(stdout, "Warning: Supposedly malformed source file '%s' (%s).\n", filename,
            SofaErrorStr(err));

    mysofa_tocartesian(sofa.get());

    PrintSofaAttributes("Info", sofa->attributes);

    fprintf(stdout, "Measurements: %u\n", sofa->M);
    fprintf(stdout, "Receivers: %u\n", sofa->R);
    fprintf(stdout, "Emitters: %u\n", sofa->E);
    fprintf(stdout, "Samples: %u\n", sofa->N);

    PrintSofaArray("SampleRate", &sofa->DataSamplingRate);
    PrintSofaArray("DataDelay", &sofa->DataDelay);

    PrintCompatibleLayout(sofa->M, sofa->SourcePosition.values);
}

int main(int argc, char *argv[])
{
    GET_UNICODE_ARGS(&argc, &argv);

    if(argc != 2)
    {
        fprintf(stdout, "Usage: %s <sofa-file>\n", argv[0]);
        return 0;
    }

    SofaInfo(argv[1]);

    return 0;
}