Use an alternate ambisonic HRTF decode layout

Similar to the previous, but includes the top and bottom HRTF responses. The
higher-order decode (for the "basic" HRTF output) also now uses 2H1P mixed-
order instead of 2H1V, which seems more stable.

4 files changed, 71 insertions, 57 deletions

diff --git a/Alc/bformatdec.c b/Alc/bformatdec.c
index bfd40b14..03ea865c 100644
--- a/Alc/bformatdec.c
+++ b/Alc/bformatdec.c
@@ -518,7 +518,7 @@ void ambiup_free(struct AmbiUpsampler **ambiup)
     }
 }
 
-void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device)
+void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device, ALfloat w_scale, ALfloat xyz_scale)
 {
     ALfloat ratio;
     ALsizei i;
@@ -560,11 +560,6 @@ void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device)
     }
     else
     {
-        /* Assumes full 3D/periphonic on the input and output mixes! */
-        ALfloat w_scale = (device->Dry.NumChannels > 9) ? W_SCALE_3H3P :
-                          (device->Dry.NumChannels > 4) ? W_SCALE_2H2P : 1.0f;
-        ALfloat xyz_scale = (device->Dry.NumChannels > 9) ? XYZ_SCALE_3H3P :
-                            (device->Dry.NumChannels > 4) ? XYZ_SCALE_2H2P : 1.0f;
         for(i = 0;i < 4;i++)
         {
             ALsizei index = GetChannelForACN(device->Dry, i);
diff --git a/Alc/bformatdec.h b/Alc/bformatdec.h
index c997c0b9..0011eb28 100644
--- a/Alc/bformatdec.h
+++ b/Alc/bformatdec.h
@@ -38,11 +38,11 @@ void bformatdec_upSample(struct BFormatDec *dec, ALfloat (*restrict OutBuffer)[B
 
 
 /* Stand-alone first-order upsampler. Kept here because it shares some stuff
- * with bformatdec.
+ * with bformatdec. Assumes a periphonic (4-channel) input mix!
  */
 struct AmbiUpsampler *ambiup_alloc();
 void ambiup_free(struct AmbiUpsampler **ambiup);
-void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device);
+void ambiup_reset(struct AmbiUpsampler *ambiup, const ALCdevice *device, ALfloat w_scale, ALfloat xyz_scale);
 
 void ambiup_process(struct AmbiUpsampler *ambiup, ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALsizei OutChannels, const ALfloat (*restrict InSamples)[BUFFERSIZE], ALsizei SamplesToDo);
 
diff --git a/Alc/hrtf.h b/Alc/hrtf.h
index b041c911..60842e8d 100644
--- a/Alc/hrtf.h
+++ b/Alc/hrtf.h
@@ -12,7 +12,7 @@
 /* The maximum number of virtual speakers used to generate HRTF coefficients
  * for decoding B-Format.
  */
-#define HRTF_AMBI_MAX_CHANNELS 16
+#define HRTF_AMBI_MAX_CHANNELS 18
 
 
 #define HRTF_HISTORY_BITS   (6)
diff --git a/Alc/panning.c b/Alc/panning.c
index b90652a3..6baff75f 100644
--- a/Alc/panning.c
+++ b/Alc/panning.c
@@ -649,6 +649,8 @@ static void InitPanning(ALCdevice *device)
         }
         else
         {
+            ALfloat w_scale=1.0f, xyz_scale=1.0f;
+
             /* FOA output is always ACN+N3D for higher-order ambisonic output.
              * The upsampler expects this and will convert it for output.
              */
@@ -661,7 +663,17 @@ static void InitPanning(ALCdevice *device)
             device->FOAOut.CoeffCount = 0;
             device->FOAOut.NumChannels = 4;
 
-            ambiup_reset(device->AmbiUp, device);
+            if(device->AmbiOrder >= 3)
+            {
+                w_scale = W_SCALE_3H3P;
+                xyz_scale = XYZ_SCALE_3H3P;
+            }
+            else
+            {
+                w_scale = W_SCALE_2H2P;
+                xyz_scale = XYZ_SCALE_2H2P;
+            }
+            ambiup_reset(device->AmbiUp, device, w_scale, xyz_scale);
         }
 
         if(ConfigValueFloat(devname, "decoder", "nfc-ref-delay", &nfc_delay) && nfc_delay > 0.0f)
@@ -870,62 +882,68 @@ static void InitHrtfPanning(ALCdevice *device)
 {
     /* NOTE: azimuth goes clockwise. */
     static const ALfloat AmbiPoints[][2] = {
-        { DEG2RAD( 35.0f), DEG2RAD( -45.0f) },
-        { DEG2RAD( 35.0f), DEG2RAD(-135.0f) },
-        { DEG2RAD( 35.0f), DEG2RAD( 135.0f) },
+        { DEG2RAD( 90.0f), DEG2RAD(   0.0f) },
         { DEG2RAD( 35.0f), DEG2RAD(  45.0f) },
+        { DEG2RAD( 35.0f), DEG2RAD( 135.0f) },
+        { DEG2RAD( 35.0f), DEG2RAD(-135.0f) },
+        { DEG2RAD( 35.0f), DEG2RAD( -45.0f) },
         { DEG2RAD(  0.0f), DEG2RAD(   0.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD( -45.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD( -90.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD(-135.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD( 180.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD( 135.0f) },
-        { DEG2RAD(  0.0f), DEG2RAD(  90.0f) },
         { DEG2RAD(  0.0f), DEG2RAD(  45.0f) },
-        { DEG2RAD(-35.0f), DEG2RAD( -45.0f) },
-        { DEG2RAD(-35.0f), DEG2RAD(-135.0f) },
-        { DEG2RAD(-35.0f), DEG2RAD( 135.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD(  90.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD( 135.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD( 180.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD(-135.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD( -90.0f) },
+        { DEG2RAD(  0.0f), DEG2RAD( -45.0f) },
         { DEG2RAD(-35.0f), DEG2RAD(  45.0f) },
+        { DEG2RAD(-35.0f), DEG2RAD( 135.0f) },
+        { DEG2RAD(-35.0f), DEG2RAD(-135.0f) },
+        { DEG2RAD(-35.0f), DEG2RAD( -45.0f) },
+        { DEG2RAD(-90.0f), DEG2RAD(   0.0f) },
     };
     static const ALfloat AmbiMatrixFOA[][MAX_AMBI_COEFFS] = {
-        { 6.25000000e-002f,  5.00000000e-002f,  1.25000000e-001f,  5.00000000e-002f },
-        { 6.25000000e-002f,  5.00000000e-002f,  1.25000000e-001f, -5.00000000e-002f },
-        { 6.25000000e-002f, -5.00000000e-002f,  1.25000000e-001f, -5.00000000e-002f },
-        { 6.25000000e-002f, -5.00000000e-002f,  1.25000000e-001f,  5.00000000e-002f },
-        { 6.25000000e-002f,  0.00000000e+000f,  0.00000000e+000f,  8.66025404e-002f },
-        { 6.25000000e-002f,  6.12372435e-002f,  0.00000000e+000f,  6.12372435e-002f },
-        { 6.25000000e-002f,  8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f,  6.12372435e-002f,  0.00000000e+000f, -6.12372435e-002f },
-        { 6.25000000e-002f,  0.00000000e+000f,  0.00000000e+000f, -8.66025404e-002f },
-        { 6.25000000e-002f, -6.12372435e-002f,  0.00000000e+000f, -6.12372435e-002f },
-        { 6.25000000e-002f, -8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f, -6.12372435e-002f,  0.00000000e+000f,  6.12372435e-002f },
-        { 6.25000000e-002f,  5.00000000e-002f, -1.25000000e-001f,  5.00000000e-002f },
-        { 6.25000000e-002f,  5.00000000e-002f, -1.25000000e-001f, -5.00000000e-002f },
-        { 6.25000000e-002f, -5.00000000e-002f, -1.25000000e-001f, -5.00000000e-002f },
-        { 6.25000000e-002f, -5.00000000e-002f, -1.25000000e-001f,  5.00000000e-002f },
+        { 5.55555556e-02f,  0.00000000e+00f,  1.23717915e-01f,  0.00000000e+00f },
+        { 5.55555556e-02f, -5.00000000e-02f,  7.14285715e-02f,  5.00000000e-02f },
+        { 5.55555556e-02f, -5.00000000e-02f,  7.14285715e-02f, -5.00000000e-02f },
+        { 5.55555556e-02f,  5.00000000e-02f,  7.14285715e-02f, -5.00000000e-02f },
+        { 5.55555556e-02f,  5.00000000e-02f,  7.14285715e-02f,  5.00000000e-02f },
+        { 5.55555556e-02f,  0.00000000e+00f,  0.00000000e+00f,  8.66025404e-02f },
+        { 5.55555556e-02f, -6.12372435e-02f,  0.00000000e+00f,  6.12372435e-02f },
+        { 5.55555556e-02f, -8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -6.12372435e-02f,  0.00000000e+00f, -6.12372435e-02f },
+        { 5.55555556e-02f,  0.00000000e+00f,  0.00000000e+00f, -8.66025404e-02f },
+        { 5.55555556e-02f,  6.12372435e-02f,  0.00000000e+00f, -6.12372435e-02f },
+        { 5.55555556e-02f,  8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  6.12372435e-02f,  0.00000000e+00f,  6.12372435e-02f },
+        { 5.55555556e-02f, -5.00000000e-02f, -7.14285715e-02f,  5.00000000e-02f },
+        { 5.55555556e-02f, -5.00000000e-02f, -7.14285715e-02f, -5.00000000e-02f },
+        { 5.55555556e-02f,  5.00000000e-02f, -7.14285715e-02f, -5.00000000e-02f },
+        { 5.55555556e-02f,  5.00000000e-02f, -7.14285715e-02f,  5.00000000e-02f },
+        { 5.55555556e-02f,  0.00000000e+00f, -1.23717915e-01f,  0.00000000e+00f },
     }, AmbiMatrixHOA[][MAX_AMBI_COEFFS] = {
-        { 6.25000000e-002f,  5.00000000e-002f,  1.25000000e-001f,  5.00000000e-002f,  4.55645099e-002f,  9.68245837e-002f,  0.00000000e+000f,  9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f,  5.00000000e-002f,  1.25000000e-001f, -5.00000000e-002f, -4.55645099e-002f,  9.68245837e-002f,  0.00000000e+000f, -9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f, -5.00000000e-002f,  1.25000000e-001f, -5.00000000e-002f,  4.55645099e-002f, -9.68245837e-002f,  0.00000000e+000f, -9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f, -5.00000000e-002f,  1.25000000e-001f,  5.00000000e-002f, -4.55645099e-002f, -9.68245837e-002f,  0.00000000e+000f,  9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f,  0.00000000e+000f,  0.00000000e+000f,  8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  1.29099445e-001f },
-        { 6.25000000e-002f,  6.12372435e-002f,  0.00000000e+000f,  6.12372435e-002f,  6.83467648e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f,  8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f, -1.29099445e-001f },
-        { 6.25000000e-002f,  6.12372435e-002f,  0.00000000e+000f, -6.12372435e-002f, -6.83467648e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f,  0.00000000e+000f,  0.00000000e+000f, -8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  1.29099445e-001f },
-        { 6.25000000e-002f, -6.12372435e-002f,  0.00000000e+000f, -6.12372435e-002f,  6.83467648e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f, -8.66025404e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f, -1.29099445e-001f },
-        { 6.25000000e-002f, -6.12372435e-002f,  0.00000000e+000f,  6.12372435e-002f, -6.83467648e-002f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f,  0.00000000e+000f },
-        { 6.25000000e-002f,  5.00000000e-002f, -1.25000000e-001f,  5.00000000e-002f,  4.55645099e-002f, -9.68245837e-002f,  0.00000000e+000f, -9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f,  5.00000000e-002f, -1.25000000e-001f, -5.00000000e-002f, -4.55645099e-002f, -9.68245837e-002f,  0.00000000e+000f,  9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f, -5.00000000e-002f, -1.25000000e-001f, -5.00000000e-002f,  4.55645099e-002f,  9.68245837e-002f,  0.00000000e+000f,  9.68245837e-002f,  0.00000000e+000f },
-        { 6.25000000e-002f, -5.00000000e-002f, -1.25000000e-001f,  5.00000000e-002f, -4.55645099e-002f,  9.68245837e-002f,  0.00000000e+000f, -9.68245837e-002f,  0.00000000e+000f },
+        { 5.55555556e-02f,  0.00000000e+00f,  1.23717915e-01f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -5.00000000e-02f,  7.14285715e-02f,  5.00000000e-02f, -4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -5.00000000e-02f,  7.14285715e-02f, -5.00000000e-02f,  4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  5.00000000e-02f,  7.14285715e-02f, -5.00000000e-02f, -4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  5.00000000e-02f,  7.14285715e-02f,  5.00000000e-02f,  4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  0.00000000e+00f,  0.00000000e+00f,  8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  1.29099445e-01f },
+        { 5.55555556e-02f, -6.12372435e-02f,  0.00000000e+00f,  6.12372435e-02f, -6.83467648e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -1.29099445e-01f },
+        { 5.55555556e-02f, -6.12372435e-02f,  0.00000000e+00f, -6.12372435e-02f,  6.83467648e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  0.00000000e+00f,  0.00000000e+00f, -8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  1.29099445e-01f },
+        { 5.55555556e-02f,  6.12372435e-02f,  0.00000000e+00f, -6.12372435e-02f, -6.83467648e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  8.66025404e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f, -1.29099445e-01f },
+        { 5.55555556e-02f,  6.12372435e-02f,  0.00000000e+00f,  6.12372435e-02f,  6.83467648e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -5.00000000e-02f, -7.14285715e-02f,  5.00000000e-02f, -4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f, -5.00000000e-02f, -7.14285715e-02f, -5.00000000e-02f,  4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  5.00000000e-02f, -7.14285715e-02f, -5.00000000e-02f, -4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  5.00000000e-02f, -7.14285715e-02f,  5.00000000e-02f,  4.55645099e-02f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
+        { 5.55555556e-02f,  0.00000000e+00f, -1.23717915e-01f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f,  0.00000000e+00f },
     };
     static const ALfloat AmbiOrderHFGainFOA[MAX_AMBI_ORDER+1] = {
-        2.82842712e+00, 1.63299316e+00
+        3.00000000e+00f, 1.73205081e+00f
     }, AmbiOrderHFGainHOA[MAX_AMBI_ORDER+1] = {
-        2.15665546e+00, 1.67053814e+00, 8.62662186e-01
+        2.40192231e+00f, 1.86052102e+00f, 9.60768923e-01f
     };
     const ALfloat (*restrict AmbiMatrix)[MAX_AMBI_COEFFS] = AmbiMatrixFOA;
     const ALfloat *restrict AmbiOrderHFGain = AmbiOrderHFGainFOA;
@@ -964,7 +982,8 @@ static void InitHrtfPanning(ALCdevice *device)
         device->FOAOut.CoeffCount = 0;
         device->FOAOut.NumChannels = 4;
 
-        ambiup_reset(device->AmbiUp, device);
+        ambiup_reset(device->AmbiUp, device, AmbiOrderHFGainFOA[0] / AmbiOrderHFGain[0],
+                     AmbiOrderHFGainFOA[1] / AmbiOrderHFGain[1]);
     }
     else
     {