Add a dual-band ambisonic decoder

This uses a virtual B-Format buffer for mixing, and then uses a dual-band
decoder for improved positional quality. This currently only works with first-
order output since first-order input (from the AL_EXT_BFROMAT extension) would
not sound correct when fed through a second- or third-order decoder.

This also does not currently implement near-field compensation since near-field
rendering effects are not implemented.

1 files changed, 8 insertions, 0 deletions

diff --git a/Alc/ALu.c b/Alc/ALu.c
index d7f68c03..5064a588 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -35,6 +35,7 @@
 #include "bs2b.h"
 #include "hrtf.h"
 #include "uhjfilter.h"
+#include "bformatdec.h"
 #include "static_assert.h"
 
 #include "mixer_defs.h"
@@ -1462,6 +1463,13 @@ ALvoid aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size)
                 device->Hrtf_Offset += SamplesToDo;
             }
         }
+        else if(device->AmbiDecoder)
+        {
+            bformatdec_process(device->AmbiDecoder,
+                device->RealOut.Buffer, device->RealOut.NumChannels,
+                device->VirtOut.Buffer, SamplesToDo
+            );
+        }
         else
         {
             if(device->Uhj_Encoder)