Limit HRTF ambisonic decoding to second-order

The generated third-order matrix has incorrect first-order coefficients,
indicating a wonky decoder. The generated second-order matrix looks more
stable.

2 files changed, 35 insertions, 38 deletions

diff --git a/alc/panning.cpp b/alc/panning.cpp
index 832fc202..1288197d 100644
--- a/alc/panning.cpp
+++ b/alc/panning.cpp
@@ -551,39 +551,37 @@ void InitHrtfPanning(ALCdevice *device)
         { Deg2Rad(-35.264390f), Deg2Rad( 135.000000f) },
     };
     static const float AmbiMatrix[][MAX_AMBI_CHANNELS]{
-        { 3.84615387e-02f,  0.00000000e+00f,  0.00000000e+00f,  8.33950391e-02f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  8.60662966e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -7.49473409e-02f,  0.00000000e+00f,  9.67566016e-02f },
-        { 3.84615387e-02f,  0.00000000e+00f,  0.00000000e+00f, -8.33950391e-02f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  8.60662966e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  7.49473409e-02f,  0.00000000e+00f, -9.67566016e-02f },
-        { 3.84615387e-02f,  8.33950391e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f, -8.60662966e-02f, -9.67566016e-02f,  0.00000000e+00f, -7.49473409e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
-        { 3.84615387e-02f, -8.33950391e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f, -8.60662966e-02f,  9.67566016e-02f,  0.00000000e+00f,  7.49473409e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
-        { 3.84615379e-02f,  0.00000000e+00f,  8.33950384e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  9.93807988e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  1.22388497e-01f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
-        { 3.84615379e-02f,  0.00000000e+00f, -8.33950384e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  9.93807988e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -1.22388497e-01f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
-        { 3.84615383e-02f,  4.53609209e-02f,  4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f, -3.21963528e-02f,  0.00000000e+00f,  6.23479680e-02f, -1.27267260e-02f,  0.00000000e+00f, -6.90065559e-02f,  0.00000000e+00f },
-        { 3.84615383e-02f,  4.53609209e-02f, -4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f, -6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f, -3.21963528e-02f,  0.00000000e+00f,  6.23479680e-02f,  1.27267260e-02f,  0.00000000e+00f,  6.90065559e-02f,  0.00000000e+00f },
-        { 3.84615383e-02f, -4.53609209e-02f,  4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f, -6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f,  3.21963528e-02f,  0.00000000e+00f, -6.23479680e-02f, -1.27267260e-02f,  0.00000000e+00f, -6.90065559e-02f,  0.00000000e+00f },
-        { 3.84615383e-02f, -4.53609209e-02f, -4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f,  3.21963528e-02f,  0.00000000e+00f, -6.23479680e-02f,  1.27267260e-02f,  0.00000000e+00f,  6.90065559e-02f,  0.00000000e+00f },
-        { 3.84615383e-02f,  0.00000000e+00f,  4.53609209e-02f,  4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f,  6.83467647e-02f,  4.30331483e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -1.27267260e-02f,  6.23479680e-02f,  6.90065559e-02f,  3.21963528e-02f },
-        { 3.84615383e-02f,  0.00000000e+00f, -4.53609209e-02f,  4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f, -6.83467647e-02f,  4.30331483e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  1.27267260e-02f,  6.23479680e-02f, -6.90065559e-02f,  3.21963528e-02f },
-        { 3.84615383e-02f,  0.00000000e+00f,  4.53609209e-02f, -4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f, -6.83467647e-02f,  4.30331483e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -1.27267260e-02f, -6.23479680e-02f,  6.90065559e-02f, -3.21963528e-02f },
-        { 3.84615383e-02f,  0.00000000e+00f, -4.53609209e-02f, -4.53609209e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f,  6.83467647e-02f,  4.30331483e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  1.27267260e-02f, -6.23479680e-02f, -6.90065559e-02f, -3.21963528e-02f },
-        { 3.84615387e-02f,  4.53609217e-02f,  0.00000000e+00f,  4.53609217e-02f,  6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f,  5.23190735e-02f,  0.00000000e+00f, -4.67609766e-02f,  0.00000000e+00f, -4.67609766e-02f,  0.00000000e+00f, -5.23190735e-02f },
-        { 3.84615387e-02f, -4.53609217e-02f,  0.00000000e+00f,  4.53609217e-02f, -6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f, -5.23190735e-02f,  0.00000000e+00f,  4.67609766e-02f,  0.00000000e+00f, -4.67609766e-02f,  0.00000000e+00f, -5.23190735e-02f },
-        { 3.84615387e-02f,  4.53609217e-02f,  0.00000000e+00f, -4.53609217e-02f, -6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f,  5.23190735e-02f,  0.00000000e+00f, -4.67609766e-02f,  0.00000000e+00f,  4.67609766e-02f,  0.00000000e+00f,  5.23190735e-02f },
-        { 3.84615387e-02f, -4.53609217e-02f,  0.00000000e+00f, -4.53609217e-02f,  6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f, -5.23190735e-02f,  0.00000000e+00f,  4.67609766e-02f,  0.00000000e+00f,  4.67609766e-02f,  0.00000000e+00f,  5.23190735e-02f },
-        { 3.84615385e-02f,  3.33333332e-02f,  3.33333335e-02f,  3.33333332e-02f,  4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f,  2.95742381e-02f,  6.33865691e-02f,  2.29081068e-02f, -3.74087810e-02f,  2.29081068e-02f,  0.00000000e+00f, -2.95742381e-02f },
-        { 3.84615385e-02f,  3.33333332e-02f, -3.33333335e-02f,  3.33333332e-02f,  4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f,  2.95742381e-02f, -6.33865691e-02f,  2.29081068e-02f,  3.74087810e-02f,  2.29081068e-02f,  0.00000000e+00f, -2.95742381e-02f },
-        { 3.84615385e-02f, -3.33333332e-02f,  3.33333335e-02f,  3.33333332e-02f, -4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f, -2.95742381e-02f, -6.33865691e-02f, -2.29081068e-02f, -3.74087810e-02f,  2.29081068e-02f,  0.00000000e+00f, -2.95742381e-02f },
-        { 3.84615385e-02f, -3.33333332e-02f, -3.33333335e-02f,  3.33333332e-02f, -4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f, -2.95742381e-02f,  6.33865691e-02f, -2.29081068e-02f,  3.74087810e-02f,  2.29081068e-02f,  0.00000000e+00f, -2.95742381e-02f },
-        { 3.84615385e-02f,  3.33333332e-02f,  3.33333335e-02f, -3.33333332e-02f, -4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f,  2.95742381e-02f, -6.33865691e-02f,  2.29081068e-02f, -3.74087810e-02f, -2.29081068e-02f,  0.00000000e+00f,  2.95742381e-02f },
-        { 3.84615385e-02f,  3.33333332e-02f, -3.33333335e-02f, -3.33333332e-02f, -4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f,  2.95742381e-02f,  6.33865691e-02f,  2.29081068e-02f,  3.74087810e-02f, -2.29081068e-02f,  0.00000000e+00f,  2.95742381e-02f },
-        { 3.84615385e-02f, -3.33333332e-02f,  3.33333335e-02f, -3.33333332e-02f,  4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f, -2.95742381e-02f,  6.33865691e-02f, -2.29081068e-02f, -3.74087810e-02f, -2.29081068e-02f,  0.00000000e+00f,  2.95742381e-02f },
-        { 3.84615385e-02f, -3.33333332e-02f, -3.33333335e-02f, -3.33333332e-02f,  4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f, -2.95742381e-02f, -6.33865691e-02f, -2.29081068e-02f,  3.74087810e-02f, -2.29081068e-02f,  0.00000000e+00f,  2.95742381e-02f },
+        { 3.84615387e-02f,  0.00000000e+00f,  0.00000000e+00f,  6.66173389e-02f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  8.60662966e-02f },
+        { 3.84615387e-02f,  0.00000000e+00f,  0.00000000e+00f, -6.66173389e-02f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  8.60662966e-02f },
+        { 3.84615387e-02f,  6.66173389e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f, -8.60662966e-02f },
+        { 3.84615387e-02f, -6.66173389e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f, -8.60662966e-02f },
+        { 3.84615379e-02f,  0.00000000e+00f,  6.66173384e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  9.93807988e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615379e-02f,  0.00000000e+00f, -6.66173384e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  9.93807988e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615383e-02f,  4.71055721e-02f,  4.71055717e-02f,  0.00000000e+00f,  0.00000000e+00f,  6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f },
+        { 3.84615383e-02f,  4.71055721e-02f, -4.71055717e-02f,  0.00000000e+00f,  0.00000000e+00f, -6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f },
+        { 3.84615383e-02f, -4.71055721e-02f,  4.71055717e-02f,  0.00000000e+00f,  0.00000000e+00f, -6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f },
+        { 3.84615383e-02f, -4.71055721e-02f, -4.71055717e-02f,  0.00000000e+00f,  0.00000000e+00f,  6.83467647e-02f,  2.48451995e-02f,  0.00000000e+00f, -4.30331483e-02f },
+        { 3.84615383e-02f,  0.00000000e+00f,  4.71055717e-02f,  4.71055721e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f,  6.83467647e-02f,  4.30331483e-02f },
+        { 3.84615383e-02f,  0.00000000e+00f, -4.71055717e-02f,  4.71055721e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f, -6.83467647e-02f,  4.30331483e-02f },
+        { 3.84615383e-02f,  0.00000000e+00f,  4.71055717e-02f, -4.71055721e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f, -6.83467647e-02f,  4.30331483e-02f },
+        { 3.84615383e-02f,  0.00000000e+00f, -4.71055717e-02f, -4.71055721e-02f,  0.00000000e+00f,  0.00000000e+00f,  2.48451995e-02f,  6.83467647e-02f,  4.30331483e-02f },
+        { 3.84615387e-02f,  4.71055721e-02f,  0.00000000e+00f,  4.71055721e-02f,  6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615387e-02f, -4.71055721e-02f,  0.00000000e+00f,  4.71055721e-02f, -6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615387e-02f,  4.71055721e-02f,  0.00000000e+00f, -4.71055721e-02f, -6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615387e-02f, -4.71055721e-02f,  0.00000000e+00f, -4.71055721e-02f,  6.83467654e-02f,  0.00000000e+00f, -4.96903997e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 3.84615385e-02f,  3.84615384e-02f,  3.84615386e-02f,  3.84615384e-02f,  4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f,  3.84615384e-02f, -3.84615386e-02f,  3.84615384e-02f,  4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f, -3.84615384e-02f,  3.84615386e-02f,  3.84615384e-02f, -4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f, -3.84615384e-02f, -3.84615386e-02f,  3.84615384e-02f, -4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f,  3.84615384e-02f,  3.84615386e-02f, -3.84615384e-02f, -4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f,  3.84615384e-02f, -3.84615386e-02f, -3.84615384e-02f, -4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f, -3.84615384e-02f,  3.84615386e-02f, -3.84615384e-02f,  4.55645099e-02f, -4.55645100e-02f,  0.00000000e+00f, -4.55645100e-02f,  0.00000000e+00f },
+        { 3.84615385e-02f, -3.84615384e-02f, -3.84615386e-02f, -3.84615384e-02f,  4.55645099e-02f,  4.55645100e-02f,  0.00000000e+00f,  4.55645100e-02f,  0.00000000e+00f },
     };
     static const float AmbiOrderHFGain1O[MAX_AMBI_ORDER+1]{
         3.60555128e+00f, 2.08166600e+00f
     }, AmbiOrderHFGain2O[MAX_AMBI_ORDER+1]{
         2.68741925e+00f, 2.08166600e+00f, 1.07496770e+00f
-    }, AmbiOrderHFGain3O[MAX_AMBI_ORDER+1]{
-        2.12652604e+00f, 1.83122879e+00f, 1.30214339e+00f, 6.48052398e-01f
     };
     static const ALuint ChansPerOrder[MAX_AMBI_ORDER+1]{ 1, 3, 5, 7 };
     const float *AmbiOrderHFGain{AmbiOrderHFGain1O};
@@ -606,11 +604,10 @@ void InitHrtfPanning(ALCdevice *device)
             { "full", HrtfRender, 1 },
             { "ambi1", NormalRender, 1 },
             { "ambi2", NormalRender, 2 },
-            { "ambi3", NormalRender, 3 },
         };
 
         const char *mode{modeopt->c_str()};
-        if(al::strcasecmp(mode, "basic") == 0)
+        if(al::strcasecmp(mode, "basic") == 0 || al::strcasecmp(mode, "ambi3") == 0)
         {
             ERR("HRTF mode \"%s\" deprecated, substituting \"%s\"\n", mode, "ambi2");
             mode = "ambi2";
@@ -635,9 +632,7 @@ void InitHrtfPanning(ALCdevice *device)
         (device->mRenderMode == HrtfRender) ? "+ Full " : "",
         device->HrtfName.c_str());
 
-    if(ambi_order >= 3)
-        AmbiOrderHFGain = AmbiOrderHFGain3O;
-    else if(ambi_order == 2)
+    if(ambi_order >= 2)
         AmbiOrderHFGain = AmbiOrderHFGain2O;
     else if(ambi_order == 1)
         AmbiOrderHFGain = AmbiOrderHFGain1O;
diff --git a/utils/alsoft-config/mainwindow.cpp b/utils/alsoft-config/mainwindow.cpp
index f4f5fd45..7b1d8a91 100644
--- a/utils/alsoft-config/mainwindow.cpp
+++ b/utils/alsoft-config/mainwindow.cpp
@@ -129,7 +129,6 @@ static const struct NameValuePair {
 }, hrtfModeList[] = {
     { "1st Order Ambisonic", "ambi1" },
     { "2nd Order Ambisonic", "ambi2" },
-    { "3rd Order Ambisonic", "ambi3" },
     { "Default (Full)", "" },
     { "Full", "full" },
 
@@ -742,10 +741,13 @@ void MainWindow::loadConfig(const QString &fname)
     ui->enableNeonCheckBox->setChecked(!disabledCpuExts.contains("neon", Qt::CaseInsensitive));
 
     QString hrtfmode{settings.value("hrtf-mode").toString().trimmed()};
-    ui->hrtfmodeSlider->setValue(3);
-    ui->hrtfmodeLabel->setText(hrtfModeList[3].name);
-    /* The "basic" mode name is no longer supported. Use "ambi2" instead. */
-    if(hrtfmode == "basic") hrtfmode = "ambi2";
+    ui->hrtfmodeSlider->setValue(2);
+    ui->hrtfmodeLabel->setText(hrtfModeList[2].name);
+    /* The "basic" mode name is no longer supported, and "ambi3" is temporarily
+     * disabled. Use "ambi2" instead.
+     */
+    if(hrtfmode == "basic" || hrtfmode == "ambi3")
+        hrtfmode = "ambi2";
     for(int i = 0;hrtfModeList[i].name[0];i++)
     {
         if(hrtfmode == hrtfModeList[i].value)