#include "config.h" #include #include #include #include #include #include #include #include #include #ifdef HAVE_SSE_INTRINSICS #include #elif defined(HAVE_NEON) #include #endif #include "albyte.h" #include "alcomplex.h" #include "alc/effectslot.h" #include "almalloc.h" #include "alnumeric.h" #include "alspan.h" #include "base.h" #include "core/ambidefs.h" #include "core/bufferline.h" #include "core/buffer_storage.h" #include "core/context.h" #include "core/devformat.h" #include "core/device.h" #include "core/filters/splitter.h" #include "core/fmt_traits.h" #include "core/mixer.h" #include "intrusive_ptr.h" #include "math_defs.h" #include "polyphase_resampler.h" #include "vector.h" namespace { /* Convolution reverb is implemented using a segmented overlap-add method. The * impulse response is broken up into multiple segments of 128 samples, and * each segment has an FFT applied with a 256-sample buffer (the latter half * left silent) to get its frequency-domain response. The resulting response * has its positive/non-mirrored frequencies saved (129 bins) in each segment. * * Input samples are similarly broken up into 128-sample segments, with an FFT * applied to each new incoming segment to get its 129 bins. A history of FFT'd * input segments is maintained, equal to the length of the impulse response. * * To apply the reverberation, each impulse response segment is convolved with * its paired input segment (using complex multiplies, far cheaper than FIRs), * accumulating into a 256-bin FFT buffer. The input history is then shifted to * align with later impulse response segments for next time. * * An inverse FFT is then applied to the accumulated FFT buffer to get a 256- * sample time-domain response for output, which is split in two halves. The * first half is the 128-sample output, and the second half is a 128-sample * (really, 127) delayed extension, which gets added to the output next time. * Convolving two time-domain responses of lengths N and M results in a time- * domain signal of length N+M-1, and this holds true regardless of the * convolution being applied in the frequency domain, so these "overflow" * samples need to be accounted for. * * To avoid a delay with gathering enough input samples to apply an FFT with, * the first segment is applied directly in the time-domain as the samples come * in. Once enough have been retrieved, the FFT is applied on the input and * it's paired with the remaining (FFT'd) filter segments for processing. */ void LoadSamples(double *RESTRICT dst, const al::byte *src, const size_t srcstep, FmtType srctype, const size_t samples) noexcept { #define HANDLE_FMT(T) case T: al::LoadSampleArray(dst, src, srcstep, samples); break switch(srctype) { HANDLE_FMT(FmtUByte); HANDLE_FMT(FmtShort); HANDLE_FMT(FmtFloat); HANDLE_FMT(FmtDouble); HANDLE_FMT(FmtMulaw); HANDLE_FMT(FmtAlaw); } #undef HANDLE_FMT } inline auto& GetAmbiScales(AmbiScaling scaletype) noexcept { switch(scaletype) { case AmbiScaling::FuMa: return AmbiScale::FromFuMa(); case AmbiScaling::SN3D: return AmbiScale::FromSN3D(); case AmbiScaling::UHJ: return AmbiScale::FromUHJ(); case AmbiScaling::N3D: break; } return AmbiScale::FromN3D(); } inline auto& GetAmbiLayout(AmbiLayout layouttype) noexcept { if(layouttype == AmbiLayout::FuMa) return AmbiIndex::FromFuMa(); return AmbiIndex::FromACN(); } inline auto& GetAmbi2DLayout(AmbiLayout layouttype) noexcept { if(layouttype == AmbiLayout::FuMa) return AmbiIndex::FromFuMa2D(); return AmbiIndex::FromACN2D(); } struct ChanMap { Channel channel; float angle; float elevation; }; using complex_d = std::complex; constexpr size_t ConvolveUpdateSize{256}; constexpr size_t ConvolveUpdateSamples{ConvolveUpdateSize / 2}; void apply_fir(al::span dst, const float *RESTRICT src, const float *RESTRICT filter) { #ifdef HAVE_SSE_INTRINSICS for(float &output : dst) { __m128 r4{_mm_setzero_ps()}; for(size_t j{0};j < ConvolveUpdateSamples;j+=4) { const __m128 coeffs{_mm_load_ps(&filter[j])}; const __m128 s{_mm_loadu_ps(&src[j])}; r4 = _mm_add_ps(r4, _mm_mul_ps(s, coeffs)); } r4 = _mm_add_ps(r4, _mm_shuffle_ps(r4, r4, _MM_SHUFFLE(0, 1, 2, 3))); r4 = _mm_add_ps(r4, _mm_movehl_ps(r4, r4)); output = _mm_cvtss_f32(r4); ++src; } #elif defined(HAVE_NEON) for(float &output : dst) { float32x4_t r4{vdupq_n_f32(0.0f)}; for(size_t j{0};j < ConvolveUpdateSamples;j+=4) r4 = vmlaq_f32(r4, vld1q_f32(&src[j]), vld1q_f32(&filter[j])); r4 = vaddq_f32(r4, vrev64q_f32(r4)); output = vget_lane_f32(vadd_f32(vget_low_f32(r4), vget_high_f32(r4)), 0); ++src; } #else for(float &output : dst) { float ret{0.0f}; for(size_t j{0};j < ConvolveUpdateSamples;++j) ret += src[j] * filter[j]; output = ret; ++src; } #endif } struct ConvolutionState final : public EffectState { FmtChannels mChannels{}; AmbiLayout mAmbiLayout{}; AmbiScaling mAmbiScaling{}; uint mAmbiOrder{}; size_t mFifoPos{0}; std::array mInput{}; al::vector,16> mFilter; al::vector,16> mOutput; alignas(16) std::array mFftBuffer{}; size_t mCurrentSegment{0}; size_t mNumConvolveSegs{0}; struct ChannelData { alignas(16) FloatBufferLine mBuffer{}; float mHfScale{}; BandSplitter mFilter{}; float Current[MAX_OUTPUT_CHANNELS]{}; float Target[MAX_OUTPUT_CHANNELS]{}; }; using ChannelDataArray = al::FlexArray; std::unique_ptr mChans; std::unique_ptr mComplexData; ConvolutionState() = default; ~ConvolutionState() override = default; void NormalMix(const al::span samplesOut, const size_t samplesToDo); void UpsampleMix(const al::span samplesOut, const size_t samplesToDo); void (ConvolutionState::*mMix)(const al::span,const size_t) {&ConvolutionState::NormalMix}; void deviceUpdate(const DeviceBase *device, const Buffer &buffer) override; void update(const ContextBase *context, const EffectSlot *slot, const EffectProps *props, const EffectTarget target) override; void process(const size_t samplesToDo, const al::span samplesIn, const al::span samplesOut) override; DEF_NEWDEL(ConvolutionState) }; void ConvolutionState::NormalMix(const al::span samplesOut, const size_t samplesToDo) { for(auto &chan : *mChans) MixSamples({chan.mBuffer.data(), samplesToDo}, samplesOut, chan.Current, chan.Target, samplesToDo, 0); } void ConvolutionState::UpsampleMix(const al::span samplesOut, const size_t samplesToDo) { for(auto &chan : *mChans) { const al::span src{chan.mBuffer.data(), samplesToDo}; chan.mFilter.processHfScale(src, chan.mHfScale); MixSamples(src, samplesOut, chan.Current, chan.Target, samplesToDo, 0); } } void ConvolutionState::deviceUpdate(const DeviceBase *device, const Buffer &buffer) { constexpr uint MaxConvolveAmbiOrder{1u}; mFifoPos = 0; mInput.fill(0.0f); decltype(mFilter){}.swap(mFilter); decltype(mOutput){}.swap(mOutput); mFftBuffer.fill(complex_d{}); mCurrentSegment = 0; mNumConvolveSegs = 0; mChans = nullptr; mComplexData = nullptr; /* An empty buffer doesn't need a convolution filter. */ if(!buffer.storage || buffer.storage->mSampleLen < 1) return; constexpr size_t m{ConvolveUpdateSize/2 + 1}; auto bytesPerSample = BytesFromFmt(buffer.storage->mType); auto realChannels = ChannelsFromFmt(buffer.storage->mChannels, buffer.storage->mAmbiOrder); auto numChannels = ChannelsFromFmt(buffer.storage->mChannels, minu(buffer.storage->mAmbiOrder, MaxConvolveAmbiOrder)); mChans = ChannelDataArray::Create(numChannels); /* The impulse response needs to have the same sample rate as the input and * output. The bsinc24 resampler is decent, but there is high-frequency * attenation that some people may be able to pick up on. Since this is * called very infrequently, go ahead and use the polyphase resampler. */ PPhaseResampler resampler; if(device->Frequency != buffer.storage->mSampleRate) resampler.init(buffer.storage->mSampleRate, device->Frequency); const auto resampledCount = static_cast( (uint64_t{buffer.storage->mSampleLen}*device->Frequency+(buffer.storage->mSampleRate-1)) / buffer.storage->mSampleRate); const BandSplitter splitter{device->mXOverFreq / static_cast(device->Frequency)}; for(auto &e : *mChans) e.mFilter = splitter; mFilter.resize(numChannels, {}); mOutput.resize(numChannels, {}); /* Calculate the number of segments needed to hold the impulse response and * the input history (rounded up), and allocate them. Exclude one segment * which gets applied as a time-domain FIR filter. Make sure at least one * segment is allocated to simplify handling. */ mNumConvolveSegs = (resampledCount+(ConvolveUpdateSamples-1)) / ConvolveUpdateSamples; mNumConvolveSegs = maxz(mNumConvolveSegs, 2) - 1; const size_t complex_length{mNumConvolveSegs * m * (numChannels+1)}; mComplexData = std::make_unique(complex_length); std::fill_n(mComplexData.get(), complex_length, complex_d{}); mChannels = buffer.storage->mChannels; mAmbiLayout = buffer.storage->mAmbiLayout; mAmbiScaling = buffer.storage->mAmbiScaling; mAmbiOrder = minu(buffer.storage->mAmbiOrder, MaxConvolveAmbiOrder); auto srcsamples = std::make_unique(maxz(buffer.storage->mSampleLen, resampledCount)); complex_d *filteriter = mComplexData.get() + mNumConvolveSegs*m; for(size_t c{0};c < numChannels;++c) { /* Load the samples from the buffer, and resample to match the device. */ LoadSamples(srcsamples.get(), buffer.samples.data() + bytesPerSample*c, realChannels, buffer.storage->mType, buffer.storage->mSampleLen); if(device->Frequency != buffer.storage->mSampleRate) resampler.process(buffer.storage->mSampleLen, srcsamples.get(), resampledCount, srcsamples.get()); /* Store the first segment's samples in reverse in the time-domain, to * apply as a FIR filter. */ const size_t first_size{minz(resampledCount, ConvolveUpdateSamples)}; std::transform(srcsamples.get(), srcsamples.get()+first_size, mFilter[c].rbegin(), [](const double d) noexcept -> float { return static_cast(d); }); size_t done{first_size}; for(size_t s{0};s < mNumConvolveSegs;++s) { const size_t todo{minz(resampledCount-done, ConvolveUpdateSamples)}; auto iter = std::copy_n(&srcsamples[done], todo, mFftBuffer.begin()); done += todo; std::fill(iter, mFftBuffer.end(), complex_d{}); forward_fft(mFftBuffer); filteriter = std::copy_n(mFftBuffer.cbegin(), m, filteriter); } } } void ConvolutionState::update(const ContextBase *context, const EffectSlot *slot, const EffectProps* /*props*/, const EffectTarget target) { /* NOTE: Stereo and Rear are slightly different from normal mixing (as * defined in alu.cpp). These are 45 degrees from center, rather than the * 30 degrees used there. * * TODO: LFE is not mixed to output. This will require each buffer channel * to have its own output target since the main mixing buffer won't have an * LFE channel (due to being B-Format). */ static const ChanMap MonoMap[1]{ { FrontCenter, 0.0f, 0.0f } }, StereoMap[2]{ { FrontLeft, Deg2Rad(-45.0f), Deg2Rad(0.0f) }, { FrontRight, Deg2Rad( 45.0f), Deg2Rad(0.0f) } }, RearMap[2]{ { BackLeft, Deg2Rad(-135.0f), Deg2Rad(0.0f) }, { BackRight, Deg2Rad( 135.0f), Deg2Rad(0.0f) } }, QuadMap[4]{ { FrontLeft, Deg2Rad( -45.0f), Deg2Rad(0.0f) }, { FrontRight, Deg2Rad( 45.0f), Deg2Rad(0.0f) }, { BackLeft, Deg2Rad(-135.0f), Deg2Rad(0.0f) }, { BackRight, Deg2Rad( 135.0f), Deg2Rad(0.0f) } }, X51Map[6]{ { FrontLeft, Deg2Rad( -30.0f), Deg2Rad(0.0f) }, { FrontRight, Deg2Rad( 30.0f), Deg2Rad(0.0f) }, { FrontCenter, Deg2Rad( 0.0f), Deg2Rad(0.0f) }, { LFE, 0.0f, 0.0f }, { SideLeft, Deg2Rad(-110.0f), Deg2Rad(0.0f) }, { SideRight, Deg2Rad( 110.0f), Deg2Rad(0.0f) } }, X61Map[7]{ { FrontLeft, Deg2Rad(-30.0f), Deg2Rad(0.0f) }, { FrontRight, Deg2Rad( 30.0f), Deg2Rad(0.0f) }, { FrontCenter, Deg2Rad( 0.0f), Deg2Rad(0.0f) }, { LFE, 0.0f, 0.0f }, { BackCenter, Deg2Rad(180.0f), Deg2Rad(0.0f) }, { SideLeft, Deg2Rad(-90.0f), Deg2Rad(0.0f) }, { SideRight, Deg2Rad( 90.0f), Deg2Rad(0.0f) } }, X71Map[8]{ { FrontLeft, Deg2Rad( -30.0f), Deg2Rad(0.0f) }, { FrontRight, Deg2Rad( 30.0f), Deg2Rad(0.0f) }, { FrontCenter, Deg2Rad( 0.0f), Deg2Rad(0.0f) }, { LFE, 0.0f, 0.0f }, { BackLeft, Deg2Rad(-150.0f), Deg2Rad(0.0f) }, { BackRight, Deg2Rad( 150.0f), Deg2Rad(0.0f) }, { SideLeft, Deg2Rad( -90.0f), Deg2Rad(0.0f) }, { SideRight, Deg2Rad( 90.0f), Deg2Rad(0.0f) } }; if(mNumConvolveSegs < 1) return; mMix = &ConvolutionState::NormalMix; for(auto &chan : *mChans) std::fill(std::begin(chan.Target), std::end(chan.Target), 0.0f); const float gain{slot->Gain}; /* TODO: UHJ should be decoded to B-Format and processed that way, since * there's no telling if it can ever do a direct-out mix (even if the * device is outputing UHJ, the effect slot can feed another effect that's * not UHJ). * * Not that UHJ should really ever be used for convolution, but it's a * valid format regardless. */ if((mChannels == FmtUHJ2 || mChannels == FmtUHJ3 || mChannels == FmtUHJ4) && target.RealOut && target.RealOut->ChannelIndex[FrontLeft] != INVALID_CHANNEL_INDEX && target.RealOut->ChannelIndex[FrontRight] != INVALID_CHANNEL_INDEX) { mOutTarget = target.RealOut->Buffer; const uint lidx = target.RealOut->ChannelIndex[FrontLeft]; const uint ridx = target.RealOut->ChannelIndex[FrontRight]; (*mChans)[0].Target[lidx] = gain; (*mChans)[1].Target[ridx] = gain; } else if(mChannels == FmtBFormat3D || mChannels == FmtBFormat2D) { DeviceBase *device{context->mDevice}; if(device->mAmbiOrder > mAmbiOrder) { mMix = &ConvolutionState::UpsampleMix; const auto scales = AmbiScale::GetHFOrderScales(mAmbiOrder, device->mAmbiOrder); (*mChans)[0].mHfScale = scales[0]; for(size_t i{1};i < mChans->size();++i) (*mChans)[i].mHfScale = scales[1]; } mOutTarget = target.Main->Buffer; auto&& scales = GetAmbiScales(mAmbiScaling); const uint8_t *index_map{(mChannels == FmtBFormat2D) ? GetAmbi2DLayout(mAmbiLayout).data() : GetAmbiLayout(mAmbiLayout).data()}; std::array coeffs{}; for(size_t c{0u};c < mChans->size();++c) { const size_t acn{index_map[c]}; coeffs[acn] = scales[acn]; ComputePanGains(target.Main, coeffs.data(), gain, (*mChans)[c].Target); coeffs[acn] = 0.0f; } } else { DeviceBase *device{context->mDevice}; al::span chanmap{}; switch(mChannels) { case FmtMono: chanmap = MonoMap; break; case FmtStereo: chanmap = StereoMap; break; case FmtRear: chanmap = RearMap; break; case FmtQuad: chanmap = QuadMap; break; case FmtX51: chanmap = X51Map; break; case FmtX61: chanmap = X61Map; break; case FmtX71: chanmap = X71Map; break; case FmtBFormat2D: case FmtBFormat3D: case FmtUHJ2: case FmtUHJ3: case FmtUHJ4: break; } mOutTarget = target.Main->Buffer; if(device->mRenderMode == RenderMode::Pairwise) { auto ScaleAzimuthFront = [](float azimuth, float scale) -> float { const float abs_azi{std::fabs(azimuth)}; if(!(abs_azi >= al::MathDefs::Pi()*0.5f)) return std::copysign(minf(abs_azi*scale, al::MathDefs::Pi()*0.5f), azimuth); return azimuth; }; for(size_t i{0};i < chanmap.size();++i) { if(chanmap[i].channel == LFE) continue; const auto coeffs = CalcAngleCoeffs(ScaleAzimuthFront(chanmap[i].angle, 2.0f), chanmap[i].elevation, 0.0f); ComputePanGains(target.Main, coeffs.data(), gain, (*mChans)[i].Target); } } else for(size_t i{0};i < chanmap.size();++i) { if(chanmap[i].channel == LFE) continue; const auto coeffs = CalcAngleCoeffs(chanmap[i].angle, chanmap[i].elevation, 0.0f); ComputePanGains(target.Main, coeffs.data(), gain, (*mChans)[i].Target); } } } void ConvolutionState::process(const size_t samplesToDo, const al::span samplesIn, const al::span samplesOut) { if(mNumConvolveSegs < 1) return; constexpr size_t m{ConvolveUpdateSize/2 + 1}; size_t curseg{mCurrentSegment}; auto &chans = *mChans; for(size_t base{0u};base < samplesToDo;) { const size_t todo{minz(ConvolveUpdateSamples-mFifoPos, samplesToDo-base)}; std::copy_n(samplesIn[0].begin() + base, todo, mInput.begin()+ConvolveUpdateSamples+mFifoPos); /* Apply the FIR for the newly retrieved input samples, and combine it * with the inverse FFT'd output samples. */ for(size_t c{0};c < chans.size();++c) { auto buf_iter = chans[c].mBuffer.begin() + base; apply_fir({std::addressof(*buf_iter), todo}, mInput.data()+1 + mFifoPos, mFilter[c].data()); auto fifo_iter = mOutput[c].begin() + mFifoPos; std::transform(fifo_iter, fifo_iter+todo, buf_iter, buf_iter, std::plus<>{}); } mFifoPos += todo; base += todo; /* Check whether the input buffer is filled with new samples. */ if(mFifoPos < ConvolveUpdateSamples) break; mFifoPos = 0; /* Move the newest input to the front for the next iteration's history. */ std::copy(mInput.cbegin()+ConvolveUpdateSamples, mInput.cend(), mInput.begin()); /* Calculate the frequency domain response and add the relevant * frequency bins to the FFT history. */ auto fftiter = std::copy_n(mInput.cbegin(), ConvolveUpdateSamples, mFftBuffer.begin()); std::fill(fftiter, mFftBuffer.end(), complex_d{}); forward_fft(mFftBuffer); std::copy_n(mFftBuffer.cbegin(), m, &mComplexData[curseg*m]); const complex_d *RESTRICT filter{mComplexData.get() + mNumConvolveSegs*m}; for(size_t c{0};c < chans.size();++c) { std::fill_n(mFftBuffer.begin(), m, complex_d{}); /* Convolve each input segment with its IR filter counterpart * (aligned in time). */ const complex_d *RESTRICT input{&mComplexData[curseg*m]}; for(size_t s{curseg};s < mNumConvolveSegs;++s) { for(size_t i{0};i < m;++i,++input,++filter) mFftBuffer[i] += *input * *filter; } input = mComplexData.get(); for(size_t s{0};s < curseg;++s) { for(size_t i{0};i < m;++i,++input,++filter) mFftBuffer[i] += *input * *filter; } /* Reconstruct the mirrored/negative frequencies to do a proper * inverse FFT. */ for(size_t i{m};i < ConvolveUpdateSize;++i) mFftBuffer[i] = std::conj(mFftBuffer[ConvolveUpdateSize-i]); /* Apply iFFT to get the 256 (really 255) samples for output. The * 128 output samples are combined with the last output's 127 * second-half samples (and this output's second half is * subsequently saved for next time). */ inverse_fft(mFftBuffer); /* The iFFT'd response is scaled up by the number of bins, so apply * the inverse to normalize the output. */ for(size_t i{0};i < ConvolveUpdateSamples;++i) mOutput[c][i] = static_cast(mFftBuffer[i].real() * (1.0/double{ConvolveUpdateSize})) + mOutput[c][ConvolveUpdateSamples+i]; for(size_t i{0};i < ConvolveUpdateSamples;++i) mOutput[c][ConvolveUpdateSamples+i] = static_cast(mFftBuffer[ConvolveUpdateSamples+i].real() * (1.0/double{ConvolveUpdateSize})); } /* Shift the input history. */ curseg = curseg ? (curseg-1) : (mNumConvolveSegs-1); } mCurrentSegment = curseg; /* Finally, mix to the output. */ (this->*mMix)(samplesOut, samplesToDo); } struct ConvolutionStateFactory final : public EffectStateFactory { al::intrusive_ptr create() override { return al::intrusive_ptr{new ConvolutionState{}}; } }; } // namespace EffectStateFactory *ConvolutionStateFactory_getFactory() { static ConvolutionStateFactory ConvolutionFactory{}; return &ConvolutionFactory; }