Remove the FOAOut mixing buffer and associated post-processes

8 files changed, 14 insertions, 298 deletions

diff --git a/Alc/alc.cpp b/Alc/alc.cpp
index b68a16e0..9bba1b52 100644
--- a/Alc/alc.cpp
+++ b/Alc/alc.cpp
@@ -1822,8 +1822,6 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
 
     device->Dry.Buffer = nullptr;
     device->Dry.NumChannels = 0;
-    device->FOAOut.Buffer = nullptr;
-    device->FOAOut.NumChannels = 0;
     device->RealOut.Buffer = nullptr;
     device->RealOut.NumChannels = 0;
     device->MixBuffer.clear();
@@ -1928,12 +1926,11 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
     );
 
     aluInitRenderer(device, hrtf_id, hrtf_appreq, hrtf_userreq);
-    TRACE("Channel config, Dry: %d, FOA: %d, Real: %d\n", device->Dry.NumChannels,
-          device->FOAOut.NumChannels, device->RealOut.NumChannels);
+    TRACE("Channel config, Main: %d, Real: %d\n", device->Dry.NumChannels,
+        device->RealOut.NumChannels);
 
     /* Allocate extra channels for any post-filter output. */
-    ALsizei num_chans{device->Dry.NumChannels + device->FOAOut.NumChannels +
-                      device->RealOut.NumChannels};
+    const ALsizei num_chans{device->Dry.NumChannels + device->RealOut.NumChannels};
 
     TRACE("Allocating %d channels, " SZFMT " bytes\n", num_chans,
           num_chans*sizeof(device->MixBuffer[0]));
@@ -1941,22 +1938,13 @@ static ALCenum UpdateDeviceParams(ALCdevice *device, const ALCint *attrList)
 
     device->Dry.Buffer = &reinterpret_cast<ALfloat(&)[BUFFERSIZE]>(device->MixBuffer[0]);
     if(device->RealOut.NumChannels != 0)
-        device->RealOut.Buffer = device->Dry.Buffer + device->Dry.NumChannels +
-                                 device->FOAOut.NumChannels;
+        device->RealOut.Buffer = device->Dry.Buffer + device->Dry.NumChannels;
     else
     {
         device->RealOut.Buffer = device->Dry.Buffer;
         device->RealOut.NumChannels = device->Dry.NumChannels;
     }
 
-    if(device->FOAOut.NumChannels != 0)
-        device->FOAOut.Buffer = device->Dry.Buffer + device->Dry.NumChannels;
-    else
-    {
-        device->FOAOut.Buffer = device->Dry.Buffer;
-        device->FOAOut.NumChannels = device->Dry.NumChannels;
-    }
-
     device->NumAuxSends = new_sends;
     TRACE("Max sources: %d (%d + %d), effect slots: %d, sends: %d\n",
           device->SourcesMax, device->NumMonoSources, device->NumStereoSources,
diff --git a/Alc/alu.cpp b/Alc/alu.cpp
index f835f9fd..6512de78 100644
--- a/Alc/alu.cpp
+++ b/Alc/alu.cpp
@@ -127,10 +127,6 @@ inline HrtfDirectMixerFunc SelectHrtfMixer(void)
 
 void ProcessHrtf(ALCdevice *device, const ALsizei SamplesToDo)
 {
-    if(AmbiUpsampler *ambiup{device->AmbiUp.get()})
-        ambiup->process(device->Dry.Buffer, device->Dry.NumChannels, device->FOAOut.Buffer,
-            device->FOAOut.NumChannels, SamplesToDo);
-
     /* HRTF is stereo output only. */
     const int lidx{(device->RealOut.ChannelName[0]==FrontLeft) ? 0 : 1};
     const int ridx{(device->RealOut.ChannelName[0]==FrontLeft) ? 1 : 0};
@@ -146,19 +142,10 @@ void ProcessHrtf(ALCdevice *device, const ALsizei SamplesToDo)
 void ProcessAmbiDec(ALCdevice *device, const ALsizei SamplesToDo)
 {
     BFormatDec *ambidec{device->AmbiDecoder.get()};
-    if(device->Dry.Buffer != device->FOAOut.Buffer)
-        ambidec->upSample(device->Dry.Buffer, device->Dry.NumChannels, device->FOAOut.Buffer,
-            device->FOAOut.NumChannels, SamplesToDo);
     ambidec->process(device->RealOut.Buffer, device->RealOut.NumChannels, device->Dry.Buffer,
         SamplesToDo);
 }
 
-void ProcessAmbiUp(ALCdevice *device, const ALsizei SamplesToDo)
-{
-    device->AmbiUp->process(device->RealOut.Buffer, device->RealOut.NumChannels,
-        device->FOAOut.Buffer, device->FOAOut.NumChannels, SamplesToDo);
-}
-
 void ProcessUhj(ALCdevice *device, const ALsizei SamplesToDo)
 {
     /* UHJ is stereo output only. */
@@ -203,8 +190,6 @@ void aluSelectPostProcess(ALCdevice *device)
         device->PostProcess = ProcessHrtf;
     else if(device->AmbiDecoder)
         device->PostProcess = ProcessAmbiDec;
-    else if(device->AmbiUp)
-        device->PostProcess = ProcessAmbiUp;
     else if(device->Uhj_Encoder)
         device->PostProcess = ProcessUhj;
     else if(device->Bs2b)
diff --git a/Alc/bformatdec.cpp b/Alc/bformatdec.cpp
index efac73ca..bb88c1b1 100644
--- a/Alc/bformatdec.cpp
+++ b/Alc/bformatdec.cpp
@@ -74,22 +74,6 @@ void BFormatDec::reset(const AmbDecConf *conf, bool allow_2band, ALsizei inchans
 
     const ALfloat xover_norm{conf->XOverFreq / static_cast<float>(srate)};
 
-    const ALsizei out_order{
-        (conf->ChanMask > AMBI_3ORDER_MASK) ? 4 :
-        (conf->ChanMask > AMBI_2ORDER_MASK) ? 3 :
-        (conf->ChanMask > AMBI_1ORDER_MASK) ? 2 : 1};
-    {
-        const ALfloat (&hfscales)[MAX_AMBI_ORDER+1] = GetDecoderHFScales(out_order);
-
-        mUpsampler[0].Splitter.init(xover_norm);
-        mUpsampler[0].Gains[sHFBand] = Ambi3DDecoderHFScale[0] / hfscales[0];
-        mUpsampler[0].Gains[sLFBand] = 1.0f;
-        mUpsampler[1].Splitter.init(xover_norm);
-        mUpsampler[1].Gains[sHFBand] = Ambi3DDecoderHFScale[1] / hfscales[1];
-        mUpsampler[1].Gains[sLFBand] = 1.0f;
-        std::fill(std::begin(mUpsampler)+2, std::end(mUpsampler), mUpsampler[1]);
-    }
-
     const bool periphonic{(conf->ChanMask&AMBI_PERIPHONIC_MASK) != 0};
     const std::array<float,MAX_AMBI_CHANNELS> &coeff_scale = GetAmbiScales(conf->CoeffScale);
     const size_t coeff_count{periphonic ? MAX_AMBI_CHANNELS : MAX_AMBI2D_CHANNELS};
@@ -138,7 +122,7 @@ void BFormatDec::reset(const AmbDecConf *conf, bool allow_2band, ALsizei inchans
     }
 }
 
-void BFormatDec::reset(const ALsizei inchans, const ALfloat xover_norm, const ALsizei chancount, const ChannelDec (&chancoeffs)[MAX_OUTPUT_CHANNELS], const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS])
+void BFormatDec::reset(const ALsizei inchans, const ALsizei chancount, const ChannelDec (&chancoeffs)[MAX_OUTPUT_CHANNELS], const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS])
 {
     mSamples.clear();
     mSamplesHF = nullptr;
@@ -154,25 +138,6 @@ void BFormatDec::reset(const ALsizei inchans, const ALfloat xover_norm, const AL
         { return mask | (1 << chan); }
     );
 
-    const ALsizei out_order{
-        (inchans > 7) ? 4 :
-        (inchans > 5) ? 3 :
-        (inchans > 3) ? 2 : 1};
-    {
-        const ALfloat (&hfscales)[MAX_AMBI_ORDER+1] = GetDecoderHFScales(out_order);
-
-        mUpsampler[0].Splitter.init(xover_norm);
-        mUpsampler[0].Gains[sHFBand] = Ambi3DDecoderHFScale[0] / hfscales[0];
-        mUpsampler[0].Gains[sLFBand] = 1.0f;
-        mUpsampler[1].Splitter.init(xover_norm);
-        mUpsampler[1].Gains[sHFBand] = Ambi3DDecoderHFScale[1] / hfscales[1];
-        mUpsampler[1].Gains[sLFBand] = 1.0f;
-        std::fill(std::begin(mUpsampler)+2, std::end(mUpsampler), mUpsampler[1]);
-
-        mUpAllpass[0].init(xover_norm);
-        std::fill(std::begin(mUpAllpass)+1, std::end(mUpAllpass), mUpAllpass[0]);
-    }
-
     for(ALsizei i{0};i < chancount;i++)
     {
         const ALfloat (&coeffs)[MAX_AMBI_CHANNELS] = chancoeffs[chanmap[i]];
@@ -220,42 +185,8 @@ void BFormatDec::process(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChan
     }
 }
 
-void BFormatDec::upSample(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*InSamples)[BUFFERSIZE], const ALsizei InChannels, const ALsizei SamplesToDo)
-{
-    /* This up-sampler leverages the differences observed in dual-band higher-
-     * order decoder matrices compared to first-order. For the same output
-     * channel configuration, the low-frequency matrix has identical
-     * coefficients in the shared input channels, while the high-frequency
-     * matrix has extra scalars applied to the W channel and X/Y/Z channels.
-     * Mixing the first-order content into the higher-order stream, with the
-     * appropriate counter-scales applied to the HF response, results in the
-     * subsequent higher-order decode generating the same response as a first-
-     * order decode.
-     */
-
-    /* NOTE: Because we can't treat the first-order signal as completely
-     * decorrelated from the existing output (it may contain the reverb, echo,
-     * etc, portion) phase interference is a possibility if not kept coherent.
-     * As such, we need to apply an all-pass on the existing output so that it
-     * stays aligned with the upsampled signal.
-     */
-
-    ASSUME(InChannels > 0);
-    for(ALsizei i{0};i < InChannels;i++)
-    {
-        mUpsampler[i].Splitter.process(mSamples[sHFBand].data(), mSamples[sLFBand].data(),
-            InSamples[i], SamplesToDo);
-        mUpAllpass[i].process(OutBuffer[i], SamplesToDo);
-        MixRowSamples(OutBuffer[i], mUpsampler[i].Gains,
-            &reinterpret_cast<ALfloat(&)[BUFFERSIZE]>(mSamples[0]), sNumBands, 0, SamplesToDo);
-    }
-    ASSUME(OutChannels > InChannels);
-    for(ALsizei i{InChannels};i < OutChannels;i++)
-        mUpAllpass[i].process(OutBuffer[i], SamplesToDo);
-}
 
-
-std::array<ALfloat,MAX_AMBI_ORDER+1> AmbiUpsampler::GetHFOrderScales(const ALsizei in_order, const ALsizei out_order) noexcept
+std::array<ALfloat,MAX_AMBI_ORDER+1> BFormatDec::GetHFOrderScales(const ALsizei in_order, const ALsizei out_order) noexcept
 {
     std::array<ALfloat,MAX_AMBI_ORDER+1> ret{};
 
@@ -270,34 +201,3 @@ std::array<ALfloat,MAX_AMBI_ORDER+1> AmbiUpsampler::GetHFOrderScales(const ALsiz
 
     return ret;
 }
-
-void AmbiUpsampler::reset(const ALsizei out_order, const ALfloat xover_norm)
-{
-    const ALfloat (&hfscales)[MAX_AMBI_ORDER+1] = GetDecoderHFScales(out_order);
-
-    mInput[0].Splitter.init(xover_norm);
-    mInput[0].Gains[sHFBand] = Ambi3DDecoderHFScale[0] / hfscales[0];
-    mInput[0].Gains[sLFBand] = 1.0f;
-    mInput[1].Splitter = mInput[0].Splitter;
-    mInput[1].Gains[sHFBand] = Ambi3DDecoderHFScale[1] / hfscales[1];
-    mInput[1].Gains[sLFBand] = 1.0f;
-    std::fill(std::begin(mInput)+2, std::end(mInput), mInput[1]);
-
-    mAllpass[0].init(xover_norm);
-    std::fill(std::begin(mAllpass)+1, std::end(mAllpass), mAllpass[0]);
-}
-
-void AmbiUpsampler::process(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*InSamples)[BUFFERSIZE], const ALsizei InChannels, const ALsizei SamplesToDo)
-{
-    ASSUME(InChannels > 0);
-    for(ALsizei i{0};i < InChannels;i++)
-    {
-        mInput[i].Splitter.process(mSamples[sHFBand], mSamples[sLFBand], InSamples[i],
-            SamplesToDo);
-        mAllpass[i].process(OutBuffer[i], SamplesToDo);
-        MixRowSamples(OutBuffer[i], mInput[i].Gains, mSamples, sNumBands, 0, SamplesToDo);
-    }
-    ASSUME(OutChannels > InChannels);
-    for(ALsizei i{InChannels};i < OutChannels;i++)
-        mAllpass[i].process(OutBuffer[i], SamplesToDo);
-}
diff --git a/Alc/bformatdec.h b/Alc/bformatdec.h
index 40097f05..29699abf 100644
--- a/Alc/bformatdec.h
+++ b/Alc/bformatdec.h
@@ -32,52 +32,21 @@ class BFormatDec {
     std::array<ALfloat,BUFFERSIZE> *mSamplesHF;
     std::array<ALfloat,BUFFERSIZE> *mSamplesLF;
 
-    SplitterAllpass mUpAllpass[MAX_OUTPUT_CHANNELS];
-    struct {
-        BandSplitter Splitter;
-        ALfloat Gains[sNumBands];
-    } mUpsampler[4];
-
     ALsizei mNumChannels;
     ALboolean mDualBand;
 
 public:
     void reset(const AmbDecConf *conf, bool allow_2band, ALsizei inchans, ALuint srate, const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS]);
 
-    void reset(const ALsizei inchans, const ALfloat xover_norm, const ALsizei chancount, const ChannelDec (&chancoeffs)[MAX_OUTPUT_CHANNELS], const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS]);
+    void reset(const ALsizei inchans, const ALsizei chancount, const ChannelDec (&chancoeffs)[MAX_OUTPUT_CHANNELS], const ALsizei (&chanmap)[MAX_OUTPUT_CHANNELS]);
 
     /* Decodes the ambisonic input to the given output channels. */
     void process(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*InSamples)[BUFFERSIZE], const ALsizei SamplesToDo);
 
-    /* Up-samples a first-order input to the decoder's configuration. */
-    void upSample(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*InSamples)[BUFFERSIZE], const ALsizei InChannels, const ALsizei SamplesToDo);
-
-    DEF_NEWDEL(BFormatDec)
-};
-
-
-/* Stand-alone first-order upsampler. Kept here because it shares some stuff
- * with bformatdec.
- */
-class AmbiUpsampler {
-    static constexpr size_t sHFBand{0};
-    static constexpr size_t sLFBand{1};
-    static constexpr size_t sNumBands{2};
-
-    SplitterAllpass mAllpass[MAX_OUTPUT_CHANNELS];
-    alignas(16) ALfloat mSamples[sNumBands][BUFFERSIZE];
-    struct {
-        BandSplitter Splitter;
-        ALfloat Gains[sNumBands];
-    } mInput[4];
-
-public:
-    void reset(const ALsizei out_order, const ALfloat xover_norm);
-    void process(ALfloat (*OutBuffer)[BUFFERSIZE], const ALsizei OutChannels, const ALfloat (*InSamples)[BUFFERSIZE], const ALsizei InChannels, const ALsizei SamplesToDo);
-
+    /* Retrieves per-order HF scaling factors for "upsampling" ambisonic data. */
     static std::array<ALfloat,MAX_AMBI_ORDER+1> GetHFOrderScales(const ALsizei in_order, const ALsizei out_order) noexcept;
 
-    DEF_NEWDEL(AmbiUpsampler)
+    DEF_NEWDEL(BFormatDec)
 };
 
 #endif /* BFORMATDEC_H */
diff --git a/Alc/effects/reverb.cpp b/Alc/effects/reverb.cpp
index 4e230004..3f0aef5c 100644
--- a/Alc/effects/reverb.cpp
+++ b/Alc/effects/reverb.cpp
@@ -585,7 +585,7 @@ ALboolean ReverbState::deviceUpdate(const ALCdevice *device)
     if(device->mAmbiOrder > 1)
     {
         mMixOut = &ReverbState::MixOutAmbiUp;
-        mOrderScales = AmbiUpsampler::GetHFOrderScales(1, device->mAmbiOrder);
+        mOrderScales = BFormatDec::GetHFOrderScales(1, device->mAmbiOrder);
     }
     else
     {
diff --git a/Alc/panning.cpp b/Alc/panning.cpp
index dbbad01b..8f6aabc0 100644
--- a/Alc/panning.cpp
+++ b/Alc/panning.cpp
@@ -392,26 +392,6 @@ void InitPanning(ALCdevice *device)
         );
         device->Dry.NumChannels = count;
 
-        if(device->mAmbiOrder < 2)
-        {
-            device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-            device->FOAOut.NumChannels = 0;
-        }
-        else
-        {
-            device->FOAOut.AmbiMap.fill(BFChannelConfig{});
-            std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+4,
-                std::begin(device->FOAOut.AmbiMap),
-                [](const ALsizei &acn) noexcept { return BFChannelConfig{1.0f, acn}; }
-            );
-            device->FOAOut.NumChannels = 4;
-
-            auto ambiup = al::make_unique<AmbiUpsampler>();
-            ambiup->reset(device->mAmbiOrder, 400.0f / static_cast<ALfloat>(device->Frequency));
-
-            device->AmbiUp = std::move(ambiup);
-        }
-
         ALfloat nfc_delay{0.0f};
         if(ConfigValueFloat(devname, "decoder", "nfc-ref-delay", &nfc_delay) && nfc_delay > 0.0f)
         {
@@ -458,26 +438,7 @@ void InitPanning(ALCdevice *device)
             ""
         );
         device->AmbiDecoder = al::make_unique<BFormatDec>();
-        device->AmbiDecoder->reset(coeffcount, 400.0f / static_cast<ALfloat>(device->Frequency),
-            count, chancoeffs, idxmap);
-
-        if(coeffcount <= 3)
-            device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-        else
-        {
-            const std::array<ALfloat,MAX_AMBI_ORDER+1> scales{AmbiUpsampler::GetHFOrderScales(1,
-                (coeffcount > 7) ? 4 :
-                (coeffcount > 5) ? 3 :
-                (coeffcount > 3) ? 2 : 1)};
-
-            device->FOAOut.AmbiMap[0] = BFChannelConfig{scales[0], AmbiIndex::From2D[0]};
-            auto ambimap_iter = std::transform(AmbiIndex::From2D.begin()+1,
-                AmbiIndex::From2D.begin()+3, std::begin(device->FOAOut.AmbiMap)+1,
-                [&scales](const ALsizei &acn) noexcept { return BFChannelConfig{scales[1], acn}; }
-            );
-            std::fill(ambimap_iter, std::end(device->FOAOut.AmbiMap), BFChannelConfig{});
-        }
-        device->FOAOut.NumChannels = 0;
+        device->AmbiDecoder->reset(coeffcount, count, chancoeffs, idxmap);
 
         device->RealOut.NumChannels = device->channelsFromFmt();
     }
@@ -520,36 +481,6 @@ void InitCustomPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei
     device->AmbiDecoder = al::make_unique<BFormatDec>();
     device->AmbiDecoder->reset(conf, false, count, device->Frequency, speakermap);
 
-    if(conf->ChanMask <= AMBI_1ORDER_MASK)
-        device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-    else
-    {
-        const std::array<ALfloat,MAX_AMBI_ORDER+1> scales{AmbiUpsampler::GetHFOrderScales(1,
-            (conf->ChanMask > AMBI_3ORDER_MASK) ? 4 :
-            (conf->ChanMask > AMBI_2ORDER_MASK) ? 3 :
-            (conf->ChanMask > AMBI_1ORDER_MASK) ? 2 : 1)};
-
-        auto ambimap_iter = std::begin(device->FOAOut.AmbiMap);
-        if((conf->ChanMask&AMBI_PERIPHONIC_MASK))
-        {
-            device->FOAOut.AmbiMap[0] = BFChannelConfig{scales[0], AmbiIndex::From3D[0]};
-            ambimap_iter = std::transform(AmbiIndex::From3D.begin()+1,
-                AmbiIndex::From3D.begin()+4, ambimap_iter+1,
-                [&scales](const ALsizei &acn) noexcept { return BFChannelConfig{scales[1], acn}; }
-            );
-        }
-        else
-        {
-            device->FOAOut.AmbiMap[0] = BFChannelConfig{scales[0], AmbiIndex::From2D[0]};
-            ambimap_iter = std::transform(AmbiIndex::From2D.begin()+1,
-                AmbiIndex::From2D.begin()+3, ambimap_iter,
-                [&scales](const ALsizei &acn) noexcept { return BFChannelConfig{scales[1], acn}; }
-            );
-        }
-        std::fill(ambimap_iter, std::end(device->FOAOut.AmbiMap), BFChannelConfig{});
-    }
-    device->FOAOut.NumChannels = 0;
-
     device->RealOut.NumChannels = device->channelsFromFmt();
 
     InitDistanceComp(device, conf, speakermap);
@@ -592,33 +523,6 @@ void InitHQPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei (&sp
     device->AmbiDecoder = al::make_unique<BFormatDec>();
     device->AmbiDecoder->reset(conf, true, count, device->Frequency, speakermap);
 
-    if(conf->ChanMask <= AMBI_1ORDER_MASK)
-    {
-        device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-        device->FOAOut.NumChannels = 0;
-    }
-    else
-    {
-        device->FOAOut.AmbiMap.fill(BFChannelConfig{});
-        if((conf->ChanMask&AMBI_PERIPHONIC_MASK))
-        {
-            count = 4;
-            std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+count,
-                std::begin(device->FOAOut.AmbiMap),
-                [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
-            );
-        }
-        else
-        {
-            count = 3;
-            std::transform(AmbiIndex::From2D.begin(), AmbiIndex::From2D.begin()+count,
-                std::begin(device->FOAOut.AmbiMap),
-                [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
-            );
-        }
-        device->FOAOut.NumChannels = count;
-    }
-
     device->RealOut.NumChannels = device->channelsFromFmt();
 
     using namespace std::placeholders;
@@ -700,16 +604,10 @@ void InitHrtfPanning(ALCdevice *device)
     /* Don't bother with HOA when using full HRTF rendering. Nothing needs it,
      * and it eases the CPU/memory load.
      */
-    std::unique_ptr<AmbiUpsampler> ambiup;
     ALsizei ambi_order{1};
     if(device->mRenderMode != HrtfRender)
     {
         ambi_order = 2;
-        ambiup = al::make_unique<AmbiUpsampler>();
-        ambiup->reset(ambi_order, 400.0f / static_cast<ALfloat>(device->Frequency));
-
-        device->AmbiUp = std::move(ambiup);
-
         AmbiOrderHFGain = AmbiOrderHFGainHOA;
     }
     device->mAmbiOrder = ambi_order;
@@ -722,20 +620,6 @@ void InitHrtfPanning(ALCdevice *device)
     );
     device->Dry.NumChannels = count;
 
-    if(ambi_order > 1)
-    {
-        device->FOAOut.AmbiMap.fill(BFChannelConfig{});
-        std::transform(std::begin(IndexMap), std::begin(IndexMap)+4, std::begin(device->FOAOut.AmbiMap),
-            [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
-        );
-        device->FOAOut.NumChannels = 4;
-    }
-    else
-    {
-        device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-        device->FOAOut.NumChannels = 0;
-    }
-
     device->RealOut.NumChannels = device->channelsFromFmt();
 
     BuildBFormatHrtf(device->mHrtf, device->mHrtfState.get(), device->Dry.NumChannels, AmbiPoints,
@@ -760,9 +644,6 @@ void InitUhjPanning(ALCdevice *device)
     );
     device->Dry.NumChannels = count;
 
-    device->FOAOut.AmbiMap = device->Dry.AmbiMap;
-    device->FOAOut.NumChannels = 0;
-
     device->RealOut.NumChannels = device->channelsFromFmt();
 }
 
@@ -897,7 +778,6 @@ void aluInitRenderer(ALCdevice *device, ALint hrtf_id, HrtfRequestMode hrtf_appr
     device->ChannelDelay.clear();
 
     device->AmbiDecoder = nullptr;
-    device->AmbiUp = nullptr;
     device->Stablizer = nullptr;
 
     if(device->FmtChans != DevFmtStereo)
diff --git a/OpenAL32/Include/alMain.h b/OpenAL32/Include/alMain.h
index 1e35b2f6..b696d7d9 100644
--- a/OpenAL32/Include/alMain.h
+++ b/OpenAL32/Include/alMain.h
@@ -641,9 +641,6 @@ struct ALCdevice {
     MixParams Dry;
     ALsizei NumChannelsPerOrder[MAX_AMBI_ORDER+1]{};
 
-    /* First-order ambisonics output, to be upsampled to the dry buffer if different. */
-    MixParams FOAOut;
-
     /* "Real" output, which will be written to the device buffer. May alias the
      * dry buffer.
      */
@@ -653,18 +650,15 @@ struct ALCdevice {
     std::unique_ptr<DirectHrtfState> mHrtfState;
     HrtfEntry *mHrtf{nullptr};
 
-    /* UHJ encoder state */
+    /* Ambisonic-to-UHJ encoder */
     std::unique_ptr<Uhj2Encoder> Uhj_Encoder;
 
-    /* High quality Ambisonic decoder */
+    /* Ambisonic decoder for speakers */
     std::unique_ptr<BFormatDec> AmbiDecoder;
 
     /* Stereo-to-binaural filter */
     std::unique_ptr<bs2b> Bs2b;
 
-    /* First-order ambisonic upsampler for higher-order output */
-    std::unique_ptr<AmbiUpsampler> AmbiUp;
-
     POSTPROCESS PostProcess{};
 
     std::unique_ptr<FrontStablizer> Stablizer;
diff --git a/OpenAL32/alSource.cpp b/OpenAL32/alSource.cpp
index fbf6bfe6..30ba02f6 100644
--- a/OpenAL32/alSource.cpp
+++ b/OpenAL32/alSource.cpp
@@ -2835,7 +2835,7 @@ AL_API ALvoid AL_APIENTRY alSourcePlayv(ALsizei n, const ALuint *sources)
         if(((*buffer)->mFmtChannels == FmtBFormat2D || (*buffer)->mFmtChannels == FmtBFormat3D) &&
            device->mAmbiOrder > 1)
         {
-            voice->AmbiScales = AmbiUpsampler::GetHFOrderScales(1, device->mAmbiOrder);
+            voice->AmbiScales = BFormatDec::GetHFOrderScales(1, device->mAmbiOrder);
             voice->AmbiSplitter[0].init(400.0f / static_cast<ALfloat>(device->Frequency));
             for(ALsizei i{1};i < voice->NumChannels;++i)
                 voice->AmbiSplitter[i] = voice->AmbiSplitter[0];