Add a sofa-info utility to check sofa files

1 files changed, 383 insertions, 0 deletions

diff --git a/utils/sofa-info.cpp b/utils/sofa-info.cpp
new file mode 100644
index 00000000..51dd8b9e
--- /dev/null
+++ b/utils/sofa-info.cpp
@@ -0,0 +1,383 @@
+/*
+ * 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 <stdlib.h>
+
+#include <cmath>
+#include <vector>
+
+#include <mysofa.h>
+
+#include "win_main_utf8.h"
+
+using uint = unsigned int;
+
+// Per-field measurement info.
+struct HrirFdT {
+    float mDistance{0.0f};
+    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 uint GetUniquelySortedElems(const uint m, const float *triplets, const int axis,
+                                   const float *const (&filters)[3], const float (&epsilons)[3],
+                                   float *elems)
+{
+    uint count{0u};
+    for(uint i{0u};i < 3*m;i += 3)
+    {
+        float elem = triplets[i + axis];
+
+        uint j;
+        for(j = 0;j < 3;j++)
+        {
+            if(filters[j] && std::fabs(triplets[i + j] - *filters[j]) > epsilons[j])
+                break;
+        }
+        if(j < 3)
+            continue;
+
+        for(j = 0;j < count;j++)
+        {
+            const float delta{elem - elems[j]};
+
+            if(delta > epsilons[axis])
+                continue;
+
+            if(delta >= -epsilons[axis])
+                break;
+
+            for(uint k{count};k > j;k--)
+                elems[k] = elems[k - 1];
+
+            elems[j] = elem;
+            count++;
+            break;
+        }
+
+        if(j >= count)
+            elems[count++] = elem;
+    }
+
+    return count;
+}
+
+/* Given a list of elements, this will produce the smallest step size that
+ * can uniformly cover a fair portion of the list.  Ideally this will be over
+ * half, but in degenerate cases this can fall to a minimum of 5 (the lower
+ * limit on elevations necessary to build a layout).
+ */
+static float GetUniformStepSize(const float epsilon, const uint m, const float *elems)
+{
+    std::vector<float> steps(m, 0.0f);
+    std::vector<uint> counts(m, 0u);
+    float step{0.0f};
+    uint count{0u};
+
+    for(uint stride{1u};stride < m/2;stride++)
+    {
+        for(uint i{0u};i < m-stride;i++)
+        {
+            const float step{elems[i + stride] - elems[i]};
+
+            uint j;
+            for(j = 0;j < count;j++)
+            {
+                if(std::fabs(step - steps[j]) < epsilon)
+                {
+                    counts[j]++;
+                    break;
+                }
+            }
+
+            if(j >= count)
+            {
+                steps[j] = step;
+                counts[j] = 1;
+                count++;
+            }
+        }
+
+        for(uint i{1u};i < count;i++)
+        {
+            if(counts[i] > counts[0])
+            {
+                steps[0] = steps[i];
+                counts[0] = counts[i];
+            }
+        }
+
+        count = 1;
+
+        if(counts[0] > m/2)
+        {
+            step = steps[0];
+            return step;
+        }
+    }
+
+    if(counts[0] > 5)
+        step = steps[0];
+    return step;
+}
+
+/* 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)
+{
+    std::vector<float> aers(3*m, 0.0f);
+    std::vector<float> elems(m, 0.0f);
+
+    fprintf(stdout, "\n");
+
+    for(uint i{0u};i < 3*m;i += 3)
+    {
+        aers[i] = xyzs[i];
+        aers[i + 1] = xyzs[i + 1];
+        aers[i + 2] = xyzs[i + 2];
+        mysofa_c2s(&aers[i]);
+    }
+
+    uint fdCount{GetUniquelySortedElems(m, aers.data(), 2,
+        (const float*[3]){ nullptr, nullptr, nullptr }, (const float[3]){ 0.1f, 0.1f, 0.001f },
+        elems.data())};
+    if(fdCount > (m / 3))
+    {
+        fprintf(stdout, "Incompatible layout (inumerable radii).\n");
+        return;
+    }
+
+    std::vector<HrirFdT> fds(fdCount);
+    for(uint fi{0u};fi < fdCount;fi++)
+        fds[fi].mDistance = elems[fi];
+
+    for(uint fi{0u};fi < fdCount;fi++)
+    {
+        float dist{fds[fi].mDistance};
+        uint evCount{GetUniquelySortedElems(m, aers.data(), 1,
+            (const float*[3]){ nullptr, nullptr, &dist }, (const float[3]){ 0.1f, 0.1f, 0.001f },
+            elems.data())};
+
+        if(evCount > (m / 3))
+        {
+            fprintf(stdout, "Incompatible layout (innumerable elevations).\n");
+            return;
+        }
+
+        float step{GetUniformStepSize(0.1f, evCount, elems.data())};
+        if(step <= 0.0f)
+        {
+            fprintf(stdout, "Incompatible layout (non-uniform elevations).\n");
+            return;
+        }
+
+        uint evStart{0u};
+        for(uint ei{0u};ei < evCount;ei++)
+        {
+            float ev{90.0f + elems[ei]};
+            float eif{std::round(ev / step)};
+
+            if(std::fabs(eif - (uint)eif) < (0.1f / step))
+            {
+                evStart = static_cast<uint>(eif);
+                break;
+            }
+        }
+
+        evCount = static_cast<uint>(std::round(180.0f / step)) + 1;
+        if(evCount < 5)
+        {
+            fprintf(stdout, "Incompatible layout (too few uniform elevations).\n");
+            return;
+        }
+
+        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++)
+        {
+            float ev{-90.0f + ei * 180.0f / (evCount - 1)};
+            uint azCount{GetUniquelySortedElems(m, aers.data(), 0,
+                (const float*[3]){ nullptr, &ev, &dist }, (const float[3]){ 0.1f, 0.1f, 0.001f },
+                elems.data())};
+
+            if(azCount > (m / 3))
+            {
+                fprintf(stdout, "Incompatible layout (innumerable azimuths).\n");
+                return;
+            }
+
+            if(ei > 0 && ei < (evCount - 1))
+            {
+                step = GetUniformStepSize(0.1f, azCount, elems.data());
+                if(step <= 0.0f)
+                {
+                    fprintf(stdout, "Incompatible layout (non-uniform azimuths).\n");
+                    return;
+                }
+
+                azCounts[ei] = static_cast<uint>(std::round(360.0f / step));
+            }
+            else if(azCount != 1)
+            {
+                fprintf(stdout, "Incompatible layout (non-singular poles).\n");
+                return;
+            }
+            else
+            {
+                azCounts[ei] = 1;
+            }
+        }
+
+        for(uint ei{0u};ei < evStart;ei++)
+            azCounts[ei] = azCounts[evCount - ei - 1];
+    }
+
+    fprintf(stdout, "Compatible Layout:\n\ndistance = %.3f", fds[0].mDistance);
+
+    for(uint fi{1u};fi < fdCount;fi++)
+        fprintf(stdout, ", %.3f", fds[fi].mDistance);
+
+    fprintf(stdout, "\nazimuths = ");
+    for(uint fi{0u};fi < fdCount;fi++)
+    {
+        for(uint ei{0u};ei < fds[fi].mEvCount;ei++)
+            fprintf(stdout, "%d%s", fds[fi].mAzCounts[ei],
+                (ei < (fds[fi].mEvCount - 1)) ? ", " :
+                (fi < (fdCount - 1)) ? ";\n           " : "\n");
+    }
+}
+
+// Load and inspect the given SOFA file.
+static void SofaInfo(const char *filename)
+{
+    struct MYSOFA_EASY sofa;
+
+    sofa.lookup = nullptr;
+    sofa.neighborhood = nullptr;
+
+    int err;
+    sofa.hrtf = mysofa_load(filename, &err);
+
+    if(!sofa.hrtf)
+    {
+        mysofa_close(&sofa);
+        fprintf(stdout, "Error: Could not load source file '%s'.\n", filename);
+        return;
+    }
+
+    err = mysofa_check(sofa.hrtf);
+    if(err != MYSOFA_OK)
+/* NOTE: Some valid SOFA files are failing this check.
+    {
+        mysofa_close(&sofa);
+        fprintf(stdout, "Error: Malformed source file '%s' (%s).\n", filename, SofaErrorStr(err));
+
+        return;
+    }
+*/
+        fprintf(stdout, "Warning: Supposedly malformed source file '%s' (%s).\n", filename, SofaErrorStr(err));
+
+    mysofa_tocartesian(sofa.hrtf);
+
+    PrintSofaAttributes("Info", sofa.hrtf->attributes);
+
+    fprintf(stdout, "Measurements: %u\n", sofa.hrtf->M);
+    fprintf(stdout, "Receivers: %u\n", sofa.hrtf->R);
+    fprintf(stdout, "Emitters: %u\n", sofa.hrtf->E);
+    fprintf(stdout, "Samples: %u\n", sofa.hrtf->N);
+
+    PrintSofaArray("SampleRate", &sofa.hrtf->DataSamplingRate);
+    PrintSofaArray("DataDelay", &sofa.hrtf->DataDelay);
+
+    PrintCompatibleLayout(sofa.hrtf->M, sofa.hrtf->SourcePosition.values);
+
+    mysofa_free(sofa.hrtf);
+}
+
+int main(const int argc, const 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;
+}
+