Merge branch 'master' into efx-experiment

7 files changed, 451 insertions, 27 deletions

diff --git a/Alc/ALc.c b/Alc/ALc.c
index 681d1a66..19144883 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -33,6 +33,7 @@
 #include "alThunk.h"
 #include "alSource.h"
 #include "alExtension.h"
+#include "bs2b.h"
 
 ///////////////////////////////////////////////////////
 // DEBUG INFORMATION
@@ -342,6 +343,8 @@ ALCvoid ProcessContext(ALCcontext *pContext)
 */
 static ALvoid InitContext(ALCcontext *pContext)
 {
+    int level;
+
     //Initialise listener
     pContext->Listener.Gain = 1.0f;
     pContext->Listener.MetersPerUnit = 1.0f;
@@ -375,6 +378,14 @@ static ALvoid InitContext(ALCcontext *pContext)
     pContext->lNumMonoSources = pContext->Device->MaxNoOfSources - pContext->lNumStereoSources;
 
     strcpy(pContext->ExtensionList, "AL_EXT_EXPONENT_DISTANCE AL_EXT_FLOAT32 AL_EXT_IMA4 AL_EXT_LINEAR_DISTANCE AL_EXT_MCFORMATS AL_EXT_OFFSET");
+
+    level = GetConfigValueInt(NULL, "cf_level", 0);
+    if(level > 0 && level <= 6)
+    {
+        pContext->bs2b = calloc(1, sizeof(*pContext->bs2b));
+        bs2b_set_srate(pContext->bs2b, pContext->Frequency);
+        bs2b_set_level(pContext->bs2b, level);
+    }
 }
 
 
@@ -408,6 +419,9 @@ static ALCvoid ExitContext(ALCcontext *pContext)
     //Invalidate context
     pContext->LastError = AL_NO_ERROR;
     pContext->InUse = AL_FALSE;
+
+    free(pContext->bs2b);
+    pContext->bs2b = NULL;
 }
 
 ///////////////////////////////////////////////////////
diff --git a/Alc/ALu.c b/Alc/ALu.c
index 1ee533e1..ce669791 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -30,6 +30,7 @@
 #include "alBuffer.h"
 #include "alThunk.h"
 #include "alListener.h"
+#include "bs2b.h"
 
 #if defined(HAVE_STDINT_H)
 #include <stdint.h>
@@ -497,9 +498,6 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
             case 4:
             /* TODO: Add center/lfe channel in spatial calculations? */
             case 6:
-            /* TODO: Special paths for 6.1 and 7.1 output would be nice */
-            case 7:
-            case 8:
                 // Apply a scalar so each individual speaker has more weight
                 PanningLR = 0.5f + (0.5f*Position[0]*1.41421356f);
                 PanningLR = __min(1.0f, PanningLR);
@@ -507,18 +505,16 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
                 PanningFB = 0.5f + (0.5f*Position[2]*1.41421356f);
                 PanningFB = __min(1.0f, PanningFB);
                 PanningFB = __max(0.0f, PanningFB);
-                drysend[FRONT_LEFT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB)); //FL Direct
-                drysend[FRONT_RIGHT] = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(1.0f-PanningFB)); //FR Direct
-                drysend[BACK_LEFT]   = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(     PanningFB)); //BL Direct
-                drysend[BACK_RIGHT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(     PanningFB)); //BR Direct
-                drysend[SIDE_LEFT]   = 0.0f;
-                drysend[SIDE_RIGHT]  = 0.0f;
+                drysend[FRONT_LEFT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                drysend[FRONT_RIGHT] = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                drysend[BACK_LEFT]   = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                drysend[BACK_RIGHT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(     PanningFB));
                 if(ALSource->Send[0].Slot.effectslot)
                 {
-                    wetsend[FRONT_LEFT]  = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB)); //FL Room
-                    wetsend[FRONT_RIGHT] = ListenerGain * WetMix * aluSqrt((     PanningLR)*(1.0f-PanningFB)); //FR Room
-                    wetsend[BACK_LEFT]   = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(     PanningFB)); //BL Room
-                    wetsend[BACK_RIGHT]  = ListenerGain * WetMix * aluSqrt((     PanningLR)*(     PanningFB)); //BR Room
+                    wetsend[FRONT_LEFT]  = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                    wetsend[FRONT_RIGHT] = ListenerGain * WetMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                    wetsend[BACK_LEFT]   = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                    wetsend[BACK_RIGHT]  = ListenerGain * WetMix * aluSqrt((     PanningLR)*(     PanningFB));
                 }
                 else
                 {
@@ -528,9 +524,71 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource,
                     wetsend[BACK_RIGHT]  = 0.0f;
                     *wetgainhf = 1.0f;
                 }
-                wetsend[SIDE_LEFT]  = 0.0f;
-                wetsend[SIDE_RIGHT] = 0.0f;
                 break;
+            case 7:
+            case 8:
+                PanningFB = 1.0f - fabs(Position[2]*1.15470054f);
+                PanningFB = __min(1.0f, PanningFB);
+                PanningFB = __max(0.0f, PanningFB);
+                PanningLR = 0.5f + (0.5*Position[0]*((1.0f-PanningFB)*2.0f));
+                PanningLR = __min(1.0f, PanningLR);
+                PanningLR = __max(0.0f, PanningLR);
+                if(Position[2] > 0.0f)
+                {
+                    drysend[BACK_LEFT]   = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                    drysend[BACK_RIGHT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                    drysend[SIDE_LEFT]   = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                    drysend[SIDE_RIGHT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(     PanningFB));
+                    drysend[FRONT_LEFT]  = 0.0f;
+                    drysend[FRONT_RIGHT] = 0.0f;
+                    if(ALSource->Send[0].Slot.effectslot)
+                    {
+                        wetsend[BACK_LEFT]   = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                        wetsend[BACK_RIGHT]  = ListenerGain * WetMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                        wetsend[SIDE_LEFT]   = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                        wetsend[SIDE_RIGHT]  = ListenerGain * WetMix * aluSqrt((     PanningLR)*(     PanningFB));
+                        wetsend[FRONT_LEFT]  = 0.0f;
+                        wetsend[FRONT_RIGHT] = 0.0f;
+                    }
+                    else
+                    {
+                        wetsend[FRONT_LEFT]  = 0.0f;
+                        wetsend[FRONT_RIGHT] = 0.0f;
+                        wetsend[SIDE_LEFT]   = 0.0f;
+                        wetsend[SIDE_RIGHT]  = 0.0f;
+                        wetsend[BACK_LEFT]   = 0.0f;
+                        wetsend[BACK_RIGHT]  = 0.0f;
+                        *wetgainhf = 1.0f;
+                    }
+                }
+                else
+                {
+                    drysend[FRONT_LEFT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                    drysend[FRONT_RIGHT] = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                    drysend[SIDE_LEFT]   = ConeVolume * ListenerGain * DryMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                    drysend[SIDE_RIGHT]  = ConeVolume * ListenerGain * DryMix * aluSqrt((     PanningLR)*(     PanningFB));
+                    drysend[BACK_LEFT]   = 0.0f;
+                    drysend[BACK_RIGHT]  = 0.0f;
+                    if(ALSource->Send[0].Slot.effectslot)
+                    {
+                        wetsend[FRONT_LEFT]  = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(1.0f-PanningFB));
+                        wetsend[FRONT_RIGHT] = ListenerGain * WetMix * aluSqrt((     PanningLR)*(1.0f-PanningFB));
+                        wetsend[SIDE_LEFT]   = ListenerGain * WetMix * aluSqrt((1.0f-PanningLR)*(     PanningFB));
+                        wetsend[SIDE_RIGHT]  = ListenerGain * WetMix * aluSqrt((     PanningLR)*(     PanningFB));
+                        wetsend[BACK_LEFT]   = 0.0f;
+                        wetsend[BACK_RIGHT]  = 0.0f;
+                    }
+                    else
+                    {
+                        wetsend[FRONT_LEFT]  = 0.0f;
+                        wetsend[FRONT_RIGHT] = 0.0f;
+                        wetsend[SIDE_LEFT]   = 0.0f;
+                        wetsend[SIDE_RIGHT]  = 0.0f;
+                        wetsend[BACK_LEFT]   = 0.0f;
+                        wetsend[BACK_RIGHT]  = 0.0f;
+                        *wetgainhf = 1.0f;
+                    }
+                }
             default:
                 break;
         }
@@ -714,20 +772,16 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
                                 value = aluComputeDrySample(ALSource, DryGainHF, sample);
                                 DryBuffer[j][FRONT_LEFT]  += value*DrySend[FRONT_LEFT];
                                 DryBuffer[j][FRONT_RIGHT] += value*DrySend[FRONT_RIGHT];
-#if 0 /* FIXME: Re-enable when proper 6-channel spatialization is used */
                                 DryBuffer[j][SIDE_LEFT]   += value*DrySend[SIDE_LEFT];
                                 DryBuffer[j][SIDE_RIGHT]  += value*DrySend[SIDE_RIGHT];
-#endif
                                 DryBuffer[j][BACK_LEFT]   += value*DrySend[BACK_LEFT];
                                 DryBuffer[j][BACK_RIGHT]  += value*DrySend[BACK_RIGHT];
                                 //Room path final mix buffer and panning
                                 value = aluComputeWetSample(ALSource, WetGainHF, sample);
                                 WetBuffer[j][FRONT_LEFT]  += value*WetSend[FRONT_LEFT];
                                 WetBuffer[j][FRONT_RIGHT] += value*WetSend[FRONT_RIGHT];
-#if 0 /* FIXME: Re-enable when proper 6-channel spatialization is used */
                                 WetBuffer[j][SIDE_LEFT]   += value*WetSend[SIDE_LEFT];
                                 WetBuffer[j][SIDE_RIGHT]  += value*WetSend[SIDE_RIGHT];
-#endif
                                 WetBuffer[j][BACK_LEFT]   += value*WetSend[BACK_LEFT];
                                 WetBuffer[j][BACK_RIGHT]  += value*WetSend[BACK_RIGHT];
                             }
@@ -883,11 +937,27 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
                     }
                     break;
                 case AL_FORMAT_STEREO8:
-                    for(i = 0;i < SamplesToDo;i++)
+                    if(ALContext->bs2b)
                     {
-                        ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT])>>8)+128);
-                        ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT])>>8)+128);
-                        buffer = ((ALubyte*)buffer) + 2;
+                        for(i = 0;i < SamplesToDo;i++)
+                        {
+                            float samples[2];
+                            samples[0] = DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT];
+                            samples[1] = DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT];
+                            bs2b_cross_feed(ALContext->bs2b, samples);
+                            ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(samples[0])>>8)+128);
+                            ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(samples[1])>>8)+128);
+                            buffer = ((ALubyte*)buffer) + 2;
+                        }
+                    }
+                    else
+                    {
+                        for(i = 0;i < SamplesToDo;i++)
+                        {
+                            ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT])>>8)+128);
+                            ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT])>>8)+128);
+                            buffer = ((ALubyte*)buffer) + 2;
+                        }
                     }
                     break;
                 case AL_FORMAT_QUAD8:
@@ -949,11 +1019,27 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma
                     }
                     break;
                 case AL_FORMAT_STEREO16:
-                    for(i = 0;i < SamplesToDo;i++)
+                    if(ALContext->bs2b)
                     {
-                        ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT]);
-                        ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT]);
-                        buffer = ((ALshort*)buffer) + 2;
+                        for(i = 0;i < SamplesToDo;i++)
+                        {
+                            float samples[2];
+                            samples[0] = DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT];
+                            samples[1] = DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT];
+                            bs2b_cross_feed(ALContext->bs2b, samples);
+                            ((ALshort*)buffer)[0] = aluF2S(samples[0]);
+                            ((ALshort*)buffer)[1] = aluF2S(samples[1]);
+                            buffer = ((ALshort*)buffer) + 2;
+                        }
+                    }
+                    else
+                    {
+                        for(i = 0;i < SamplesToDo;i++)
+                        {
+                            ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT] +WetBuffer[i][FRONT_LEFT]);
+                            ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]+WetBuffer[i][FRONT_RIGHT]);
+                            buffer = ((ALshort*)buffer) + 2;
+                        }
                     }
                     break;
                 case AL_FORMAT_QUAD16:
diff --git a/Alc/bs2b.c b/Alc/bs2b.c
new file mode 100644
index 00000000..069ed614
--- /dev/null
+++ b/Alc/bs2b.c
@@ -0,0 +1,201 @@
+/*-

+ * Copyright (c) 2005 Boris Mikhaylov

+ *

+ * Permission is hereby granted, free of charge, to any person obtaining

+ * a copy of this software and associated documentation files (the

+ * "Software"), to deal in the Software without restriction, including

+ * without limitation the rights to use, copy, modify, merge, publish,

+ * distribute, sublicense, and/or sell copies of the Software, and to

+ * permit persons to whom the Software is furnished to do so, subject to

+ * the following conditions:

+ *

+ * The above copyright notice and this permission notice shall be

+ * included in all copies or substantial portions of the Software.

+ *

+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

+ */

+

+#include <math.h>

+

+#include "bs2b.h"

+

+#ifndef M_PI

+#define M_PI  3.14159265358979323846

+#endif

+

+/* Single pole IIR filter.

+ * O[n] = a0*I[n] + a1*I[n-1] + b1*O[n-1]

+ */

+

+/* Lowpass filter */

+#define lo_filter(in, out_1) (bs2b->a0_lo*(in) + bs2b->b1_lo*(out_1))

+

+/* Highboost filter */

+#define hi_filter(in, in_1, out_1) (bs2b->a0_hi*(in) + bs2b->a1_hi*(in_1) + bs2b->b1_hi*(out_1))

+

+/* Set up all data. */

+static void init(struct bs2b *bs2b)

+{

+    double Fc_lo, Fc_hi;

+    double G_lo,  G_hi;

+    double x;

+

+    if ((bs2b->srate > 192000) || (bs2b->srate < 2000))

+        bs2b->srate = BS2B_DEFAULT_SRATE;

+

+    switch(bs2b->level)

+    {

+    case BS2B_LOW_CLEVEL: /* Low crossfeed level */

+        Fc_lo = 360.0;

+        Fc_hi = 501.0;

+        G_lo  = 0.398107170553497;

+        G_hi  = 0.205671765275719;

+        break;

+

+    case BS2B_MIDDLE_CLEVEL: /* Middle crossfeed level */

+        Fc_lo = 500.0;

+        Fc_hi = 711.0;

+        G_lo  = 0.459726988530872;

+        G_hi  = 0.228208484414988;

+        break;

+

+    case BS2B_HIGH_CLEVEL: /* High crossfeed level (virtual speakers are closer to itself) */

+        Fc_lo = 700.0;

+        Fc_hi = 1021.0;

+        G_lo  = 0.530884444230988;

+        G_hi  = 0.250105790667544;

+        break;

+

+    case BS2B_LOW_ECLEVEL: /* Low easy crossfeed level */

+        Fc_lo = 360.0;

+        Fc_hi = 494.0;

+        G_lo  = 0.316227766016838;

+        G_hi  = 0.168236228897329;

+        break;

+

+    case BS2B_MIDDLE_ECLEVEL: /* Middle easy crossfeed level */

+        Fc_lo = 500.0;

+        Fc_hi = 689.0;

+        G_lo  = 0.354813389233575;

+        G_hi  = 0.187169483835901;

+        break;

+

+    default: /* High easy crossfeed level */

+        bs2b->level = BS2B_HIGH_ECLEVEL;

+

+        Fc_lo = 700.0;

+        Fc_hi = 975.0;

+        G_lo  = 0.398107170553497;

+        G_hi  = 0.205671765275719;

+        break;

+    } /* switch */

+

+    /* $fc = $Fc / $s;

+     * $d  = 1 / 2 / pi / $fc;

+     * $x  = exp(-1 / $d);

+     */

+

+    x           = exp(-2.0 * M_PI * Fc_lo / bs2b->srate);

+    bs2b->b1_lo = x;

+    bs2b->a0_lo = G_lo * (1.0 - x);

+

+    x           = exp(-2.0 * M_PI * Fc_hi / bs2b->srate);

+    bs2b->b1_hi = x;

+    bs2b->a0_hi = 1.0 - G_hi * (1.0 - x);

+    bs2b->a1_hi = -x;

+

+    bs2b->gain  = 1.0 / (1.0 - G_hi + G_lo);

+

+    bs2b_clear(bs2b);

+} /* init */

+

+/* Exported functions.

+ * See descriptions in "bs2b.h"

+ */

+

+void bs2b_set_level(struct bs2b *bs2b, int level)

+{

+    if(level == bs2b->level)

+        return;

+    bs2b->level = level;

+    init(bs2b);

+} /* bs2b_set_level */

+

+int bs2b_get_level(struct bs2b *bs2b)

+{

+    return bs2b->level;

+} /* bs2b_get_level */

+

+void bs2b_set_srate(struct bs2b *bs2b, int srate)

+{

+    if (srate == bs2b->srate)

+        return;

+    bs2b->srate = srate;

+    init(bs2b);

+} /* bs2b_set_srate */

+

+int bs2b_get_srate(struct bs2b *bs2b)

+{

+    return bs2b->srate;

+} /* bs2b_get_srate */

+

+void bs2b_clear(struct bs2b *bs2b)

+{

+    int loopv = sizeof(bs2b->last_sample);

+

+    while (loopv)

+    {

+        ((char *)&bs2b->last_sample)[--loopv] = 0;

+    }

+} /* bs2b_clear */

+

+int bs2b_is_clear(struct bs2b *bs2b)

+{

+    int loopv = sizeof(bs2b->last_sample);

+

+    while (loopv)

+    {

+        if (((char *)&bs2b->last_sample)[--loopv] != 0)

+            return 0;

+    }

+    return 1;

+} /* bs2b_is_clear */

+

+void bs2b_cross_feed(struct bs2b *bs2b, float *sample)

+{

+    /* Lowpass filter */

+    bs2b->last_sample.lo[0] = lo_filter(sample[0], bs2b->last_sample.lo[0]);

+    bs2b->last_sample.lo[1] = lo_filter(sample[1], bs2b->last_sample.lo[1]);

+

+    /* Highboost filter */

+    bs2b->last_sample.hi[0] = hi_filter(sample[0], bs2b->last_sample.asis[0], bs2b->last_sample.hi[0]);

+    bs2b->last_sample.hi[1] = hi_filter(sample[1], bs2b->last_sample.asis[1], bs2b->last_sample.hi[1]);

+    bs2b->last_sample.asis[0] = sample[0];

+    bs2b->last_sample.asis[1] = sample[1];

+

+    /* Crossfeed */

+    sample[0] = bs2b->last_sample.hi[0] + bs2b->last_sample.lo[1];

+    sample[1] = bs2b->last_sample.hi[1] + bs2b->last_sample.lo[0];

+

+    /* Bass boost cause allpass attenuation */

+    sample[0] *= bs2b->gain;

+    sample[1] *= bs2b->gain;

+

+    /* Clipping of overloaded samples */

+#if 0

+    if (sample[0] > 1.0)

+        sample[0] = 1.0;

+    if (sample[0] < -1.0)

+        sample[0] = -1.0;

+    if (sample[1] > 1.0)

+        sample[1] = 1.0;

+    if (sample[1] < -1.0)

+        sample[1] = -1.0;

+#endif

+} /* bs2b_cross_feed */

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9bab5884..f77f340a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -182,6 +182,7 @@ SET(ALC_OBJS  Alc/ALc.c
               Alc/alcConfig.c
               Alc/alcRing.c
               Alc/alcThread.c
+              Alc/bs2b.c
 )
 
 SET(BACKENDS "")
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index a5e5184a..a1857c97 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -181,6 +181,8 @@ struct ALCcontext_struct
     ALCdevice  *Device;
     ALCchar     ExtensionList[1024];
 
+    struct bs2b *bs2b;
+
     ALCcontext *next;
 };
 
diff --git a/OpenAL32/Include/bs2b.h b/OpenAL32/Include/bs2b.h
new file mode 100644
index 00000000..baf50d0c
--- /dev/null
+++ b/OpenAL32/Include/bs2b.h
@@ -0,0 +1,109 @@
+/*-

+ * Copyright (c) 2005 Boris Mikhaylov

+ *

+ * Permission is hereby granted, free of charge, to any person obtaining

+ * a copy of this software and associated documentation files (the

+ * "Software"), to deal in the Software without restriction, including

+ * without limitation the rights to use, copy, modify, merge, publish,

+ * distribute, sublicense, and/or sell copies of the Software, and to

+ * permit persons to whom the Software is furnished to do so, subject to

+ * the following conditions:

+ *

+ * The above copyright notice and this permission notice shall be

+ * included in all copies or substantial portions of the Software.

+ *

+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

+ */

+

+#ifndef BS2B_H

+#define BS2B_H

+

+/* Number of crossfeed levels */

+#define BS2B_CLEVELS           3

+

+/* Normal crossfeed levels */

+#define BS2B_HIGH_CLEVEL       3

+#define BS2B_MIDDLE_CLEVEL     2

+#define BS2B_LOW_CLEVEL        1

+

+/* Easy crossfeed levels */

+#define BS2B_HIGH_ECLEVEL      BS2B_HIGH_CLEVEL    + BS2B_CLEVELS

+#define BS2B_MIDDLE_ECLEVEL    BS2B_MIDDLE_CLEVEL  + BS2B_CLEVELS

+#define BS2B_LOW_ECLEVEL       BS2B_LOW_CLEVEL     + BS2B_CLEVELS

+

+/* Default crossfeed levels */

+#define BS2B_DEFAULT_CLEVEL    BS2B_HIGH_ECLEVEL

+/* Default sample rate (Hz) */

+#define BS2B_DEFAULT_SRATE     44100

+

+#ifdef __cplusplus

+extern "C" {

+#endif /* __cplusplus */

+

+struct bs2b {

+    int level;  /* Crossfeed level */

+    int srate;   /* Sample rate (Hz) */

+

+    /* Lowpass IIR filter coefficients */

+    double a0_lo;

+    double b1_lo;

+

+    /* Highboost IIR filter coefficients */

+    double a0_hi;

+    double a1_hi;

+    double b1_hi;

+

+    /* Global gain against overloading */

+    double gain;

+

+    /* Buffer of last filtered sample.

+     * [0] - first channel, [1] - second channel

+     */

+    struct t_last_sample {

+        double asis[2];

+        double lo[2];

+        double hi[2];

+    } last_sample;

+};

+

+/* Clear buffers and set new coefficients with new crossfeed level value.

+ * level - crossfeed level of *LEVEL values.

+ */

+void bs2b_set_level(struct bs2b *bs2b, int level);

+

+/* Return current crossfeed level value */

+int bs2b_get_level(struct bs2b *bs2b);

+

+/* Clear buffers and set new coefficients with new sample rate value.

+ * srate - sample rate by Hz.

+ */

+void bs2b_set_srate(struct bs2b *bs2b, int srate);

+

+/* Return current sample rate value */

+int bs2b_get_srate(struct bs2b *bs2b);

+

+/* Clear buffer */

+void bs2b_clear(struct bs2b *bs2b);

+

+/* Return 1 if buffer is clear */

+int bs2b_is_clear(struct bs2b *bs2b);

+

+/* Crossfeeds one stereo sample that are pointed by sample.

+ * [0] - first channel, [1] - second channel.

+ * Returns crossfided samle by sample pointer.

+ */

+

+/* sample poits to floats */

+void bs2b_cross_feed(struct bs2b *bs2b, float *sample);

+

+#ifdef __cplusplus

+}    /* extern "C" */

+#endif /* __cplusplus */

+

+#endif /* BS2B_H */

diff --git a/openalrc.sample b/openalrc.sample
index cb4b28dc..0e378a84 100644
--- a/openalrc.sample
+++ b/openalrc.sample
@@ -23,6 +23,17 @@ format = AL_FORMAT_STEREO16  # Sets the output format. Can be one of:
                              # AL_FORMAT_71CHN16  (16-bit 7.1 output)
                              # Default is AL_FORMAT_STEREO16
 
+cf_level = 0  # Sets the crossfeed level for stereo output. Valid values are:
+              # 0 - No crossfeed
+              # 1 - Low crossfeed
+              # 2 - Middle crossfeed
+              # 3 - High crossfeed (virtual speakers are closer to itself)
+              # 4 - Low easy crossfeed
+              # 5 - Middle easy crossfeed
+              # 6 - High easy crossfeed
+              # Default is 0. Users of headphones may want to try various
+              # settings. Has no effect on non-stereo modes.
+
 frequency = 44100  # Sets the output frequency. Default is 44100
 
 refresh = 0  # Sets the number of frames-per-update. Default is calculated as