openal-soft/alc/effects/convolution.cpp
Chris Robinson c52bf8c401 Rework effect slot buffer setting
Rather than creating an effect-specific buffer that gets passed along as a
property, the buffer is set the effect state when the effect state is created,
the device is updated, or the buffer is changed. The buffer can only be set
while the effect slot isn't playing, so it won't be changed or updated while
the mixer is processing the effect state.
2020-09-05 20:48:56 -07:00

538 lines
19 KiB
C++

#include "config.h"
#include "AL/al.h"
#include "AL/alc.h"
#include "al/auxeffectslot.h"
#include "alcmain.h"
#include "alcomplex.h"
#include "alcontext.h"
#include "almalloc.h"
#include "alspan.h"
#include "ambidefs.h"
#include "bformatdec.h"
#include "buffer_storage.h"
#include "effects/base.h"
#include "filters/splitter.h"
#include "fmt_traits.h"
#include "logging.h"
#include "polyphase_resampler.h"
namespace {
/* Convolution reverb is implemented using a segmented overlap-add method. The
* impulse response is broken up into multiple segments of 512 samples, and
* each segment has an FFT applied with a 1024-sample buffer (the latter half
* left silent) to get its frequency-domain response. The resulting response
* has its positive/non-mirrored frequencies saved (513 bins) in each segment.
*
* Input samples are similarly broken up into 512-sample segments, with an FFT
* applied to each new incoming segment to get its 513 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 1024-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 1024-
* sample time-domain response for output, which is split in two halves. The
* first half is the 512-sample output, and the second half is a 512-sample
* (really, 511) 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.
*
* Limitations:
* There is currently a 512-sample delay on the output, as a result of needing
* to collect that many input samples to do an FFT with. This can be fixed by
* excluding the first impulse response segment from being FFT'd, and applying
* it directly in the time domain. This will have higher CPU consumption, but
* it won't have to wait before generating output.
*/
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<T>(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
}
auto GetAmbiScales(AmbiScaling scaletype) noexcept -> const std::array<float,MAX_AMBI_CHANNELS>&
{
if(scaletype == AmbiScaling::FuMa) return AmbiScale::FromFuMa;
if(scaletype == AmbiScaling::SN3D) return AmbiScale::FromSN3D;
return AmbiScale::FromN3D;
}
auto GetAmbiLayout(AmbiLayout layouttype) noexcept -> const std::array<uint8_t,MAX_AMBI_CHANNELS>&
{
if(layouttype == AmbiLayout::FuMa) return AmbiIndex::FromFuMa;
return AmbiIndex::FromACN;
}
auto GetAmbi2DLayout(AmbiLayout layouttype) noexcept -> const std::array<uint8_t,MAX_AMBI2D_CHANNELS>&
{
if(layouttype == AmbiLayout::FuMa) return AmbiIndex::FromFuMa2D;
return AmbiIndex::From2D;
}
using complex_d = std::complex<double>;
constexpr size_t ConvolveUpdateSize{1024};
constexpr size_t ConvolveUpdateSamples{ConvolveUpdateSize / 2};
struct ConvolutionFilter {
FmtChannels mChannels{};
AmbiLayout mAmbiLayout{};
AmbiScaling mAmbiScaling{};
ALuint mAmbiOrder{};
size_t mFifoPos{0};
al::vector<std::array<double,ConvolveUpdateSamples*2>,16> mOutput;
alignas(16) std::array<complex_d,ConvolveUpdateSize> 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<ChannelData>;
std::unique_ptr<ChannelDataArray> mChans;
std::unique_ptr<complex_d[]> mComplexData;
ConvolutionFilter(size_t numChannels) : mChans{ChannelDataArray::Create(numChannels)}
{ }
bool init(const ALCdevice *device, const BufferStorage &buffer);
void NormalMix(const al::span<FloatBufferLine> samplesOut, const size_t samplesToDo);
void UpsampleMix(const al::span<FloatBufferLine> samplesOut, const size_t samplesToDo);
void (ConvolutionFilter::*mMix)(const al::span<FloatBufferLine>,const size_t)
{&ConvolutionFilter::NormalMix};
void update(al::span<FloatBufferLine> &outTarget, const ALCcontext *context,
const ALeffectslot *slot, const EffectProps *props, const EffectTarget target);
void process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn,
const al::span<FloatBufferLine> samplesOut);
DEF_NEWDEL(ConvolutionFilter)
};
bool ConvolutionFilter::init(const ALCdevice *device, const BufferStorage &buffer)
{
constexpr size_t m{ConvolveUpdateSize/2 + 1};
/* FIXME: Support anything. */
if(buffer.mChannels != FmtMono && buffer.mChannels != FmtStereo
&& buffer.mChannels != FmtBFormat2D && buffer.mChannels != FmtBFormat3D)
return false;
if((buffer.mChannels == FmtBFormat2D || buffer.mChannels == FmtBFormat3D)
&& buffer.mAmbiOrder > 1)
return false;
/* 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
* very infrequent called, go ahead and use the polyphase resampler.
*/
PPhaseResampler resampler;
if(device->Frequency != buffer.mSampleRate)
resampler.init(buffer.mSampleRate, device->Frequency);
const auto resampledCount = static_cast<ALuint>(
(uint64_t{buffer.mSampleLen}*device->Frequency + (buffer.mSampleRate-1)) /
buffer.mSampleRate);
auto bytesPerSample = BytesFromFmt(buffer.mType);
auto realChannels = ChannelsFromFmt(buffer.mChannels, buffer.mAmbiOrder);
auto numChannels = mChans->size();
const BandSplitter splitter{400.0f / static_cast<float>(device->Frequency)};
for(auto &e : *mChans)
e.mFilter = splitter;
mOutput.resize(numChannels, {});
/* Calculate the number of segments needed to hold the impulse response and
* the input history (rounded up), and allocate them.
*/
mNumConvolveSegs = (resampledCount+(ConvolveUpdateSamples-1)) / ConvolveUpdateSamples;
const size_t complex_length{mNumConvolveSegs * m * (numChannels+1)};
mComplexData = std::make_unique<complex_d[]>(complex_length);
std::fill_n(mComplexData.get(), complex_length, complex_d{});
mChannels = buffer.mChannels;
mAmbiLayout = buffer.mAmbiLayout;
mAmbiScaling = buffer.mAmbiScaling;
mAmbiOrder = buffer.mAmbiOrder;
auto fftbuffer = std::make_unique<std::array<complex_d,ConvolveUpdateSize>>();
auto srcsamples = std::make_unique<double[]>(maxz(buffer.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.mData.data() + bytesPerSample*c, realChannels,
buffer.mType, buffer.mSampleLen);
if(device->Frequency != buffer.mSampleRate)
resampler.process(buffer.mSampleLen, srcsamples.get(), resampledCount,
srcsamples.get());
size_t done{0};
for(size_t s{0};s < mNumConvolveSegs;++s)
{
const size_t todo{minz(resampledCount-done, ConvolveUpdateSamples)};
auto iter = std::copy_n(&srcsamples[done], todo, fftbuffer->begin());
done += todo;
std::fill(iter, fftbuffer->end(), complex_d{});
complex_fft(*fftbuffer, -1.0);
filteriter = std::copy_n(fftbuffer->cbegin(), m, filteriter);
}
}
return true;
}
void ConvolutionFilter::NormalMix(const al::span<FloatBufferLine> samplesOut,
const size_t samplesToDo)
{
for(auto &chan : *mChans)
MixSamples({chan.mBuffer.data(), samplesToDo}, samplesOut, chan.Current, chan.Target,
samplesToDo, 0);
}
void ConvolutionFilter::UpsampleMix(const al::span<FloatBufferLine> samplesOut,
const size_t samplesToDo)
{
for(auto &chan : *mChans)
{
const al::span<float> src{chan.mBuffer.data(), samplesToDo};
chan.mFilter.processHfScale(src, chan.mHfScale);
MixSamples(src, samplesOut, chan.Current, chan.Target, samplesToDo, 0);
}
}
void ConvolutionFilter::update(al::span<FloatBufferLine> &outTarget, const ALCcontext *context,
const ALeffectslot *slot, const EffectProps* /*props*/, const EffectTarget target)
{
ALCdevice *device{context->mDevice.get()};
mMix = &ConvolutionFilter::NormalMix;
/* The iFFT'd response is scaled up by the number of bins, so apply the
* inverse to the output mixing gain.
*/
constexpr size_t m{ConvolveUpdateSize/2 + 1};
const float gain{slot->Params.Gain * (1.0f/m)};
auto &chans = *mChans;
if(mChannels == FmtBFormat3D || mChannels == FmtBFormat2D)
{
if(device->mAmbiOrder > mAmbiOrder)
{
mMix = &ConvolutionFilter::UpsampleMix;
const auto scales = BFormatDec::GetHFOrderScales(mAmbiOrder, device->mAmbiOrder);
chans[0].mHfScale = scales[0];
for(size_t i{1};i < chans.size();++i)
chans[i].mHfScale = scales[1];
}
outTarget = target.Main->Buffer;
const auto &scales = GetAmbiScales(mAmbiScaling);
const uint8_t *index_map{(mChannels == FmtBFormat2D) ?
GetAmbi2DLayout(mAmbiLayout).data() :
GetAmbiLayout(mAmbiLayout).data()};
std::array<float,MAX_AMBI_CHANNELS> coeffs{};
for(size_t c{0u};c < chans.size();++c)
{
const size_t acn{index_map[c]};
coeffs[acn] = scales[acn];
ComputePanGains(target.Main, coeffs.data(), gain, chans[c].Target);
coeffs[acn] = 0.0f;
}
}
else if(mChannels == FmtStereo)
{
/* TODO: Add a "direct channels" setting for this effect? */
const ALuint lidx{!target.RealOut ? INVALID_CHANNEL_INDEX :
GetChannelIdxByName(*target.RealOut, FrontLeft)};
const ALuint ridx{!target.RealOut ? INVALID_CHANNEL_INDEX :
GetChannelIdxByName(*target.RealOut, FrontRight)};
if(lidx != INVALID_CHANNEL_INDEX && ridx != INVALID_CHANNEL_INDEX)
{
outTarget = target.RealOut->Buffer;
chans[0].Target[lidx] = gain;
chans[1].Target[ridx] = gain;
}
else
{
const auto lcoeffs = CalcDirectionCoeffs({-1.0f, 0.0f, 0.0f}, 0.0f);
const auto rcoeffs = CalcDirectionCoeffs({ 1.0f, 0.0f, 0.0f}, 0.0f);
outTarget = target.Main->Buffer;
ComputePanGains(target.Main, lcoeffs.data(), gain, chans[0].Target);
ComputePanGains(target.Main, rcoeffs.data(), gain, chans[1].Target);
}
}
else if(mChannels == FmtMono)
{
const auto coeffs = CalcDirectionCoeffs({0.0f, 0.0f, -1.0f}, 0.0f);
outTarget = target.Main->Buffer;
ComputePanGains(target.Main, coeffs.data(), gain, chans[0].Target);
}
}
void ConvolutionFilter::process(const size_t samplesToDo,
const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut)
{
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)};
/* Retrieve the output samples from the FIFO and fill in the new input
* samples.
*/
for(size_t c{0};c < chans.size();++c)
{
auto fifo_iter = mOutput[c].begin() + mFifoPos;
std::transform(fifo_iter, fifo_iter+todo, chans[c].mBuffer.begin()+base,
[](double d) noexcept -> float { return static_cast<float>(d); });
}
std::copy_n(samplesIn[0].begin()+base, todo, mFftBuffer.begin()+mFifoPos);
mFifoPos += todo;
base += todo;
/* Check whether FIFO buffer is filled with new samples. */
if(mFifoPos < ConvolveUpdateSamples) break;
mFifoPos = 0;
/* Calculate the frequency domain response and add the relevant
* frequency bins to the input history.
*/
complex_fft(mFftBuffer, -1.0);
std::copy_n(mFftBuffer.begin(), m, &mComplexData[curseg*m]);
mFftBuffer.fill(complex_d{});
const complex_d *RESTRICT filter{mComplexData.get() + mNumConvolveSegs*m};
for(size_t c{0};c < chans.size();++c)
{
/* 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;
}
/* Apply iFFT to get the 1024 (really 1023) samples for output. The
* 512 output samples are combined with the last output's 511
* second-half samples (and this output's second half is
* subsequently saved for next time).
*/
complex_fft(mFftBuffer, 1.0);
for(size_t i{0};i < ConvolveUpdateSamples;++i)
mOutput[c][i] = mFftBuffer[i].real() + mOutput[c][ConvolveUpdateSamples+i];
for(size_t i{0};i < ConvolveUpdateSamples;++i)
mOutput[c][ConvolveUpdateSamples+i] = mFftBuffer[ConvolveUpdateSamples+i].real();
mFftBuffer.fill(complex_d{});
}
/* Shift the input history. */
curseg = curseg ? (curseg-1) : (mNumConvolveSegs-1);
}
mCurrentSegment = curseg;
/* Finally, mix to the output. */
(this->*mMix)(samplesOut, samplesToDo);
}
struct ConvolutionState final : public EffectState {
std::unique_ptr<ConvolutionFilter> mFilter;
ConvolutionState() = default;
~ConvolutionState() override = default;
void deviceUpdate(const ALCdevice *device) override;
void setBuffer(const ALCdevice *device, const BufferStorage *buffer) override;
void update(const ALCcontext *context, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target) override;
void process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut) override;
DEF_NEWDEL(ConvolutionState)
};
void ConvolutionState::deviceUpdate(const ALCdevice* /*device*/)
{
}
void ConvolutionState::setBuffer(const ALCdevice *device, const BufferStorage *buffer)
{
mFilter = nullptr;
/* An empty buffer doesn't need a convolution filter. */
if(!buffer || buffer->mSampleLen < 1) return;
auto numChannels = ChannelsFromFmt(buffer->mChannels,
minu(buffer->mAmbiOrder, device->mAmbiOrder));
mFilter.reset(new ConvolutionFilter{numChannels});
if(!mFilter->init(device, *buffer))
mFilter = nullptr;
}
void ConvolutionState::update(const ALCcontext *context, const ALeffectslot *slot,
const EffectProps *props, const EffectTarget target)
{
if(mFilter)
mFilter->update(mOutTarget, context, slot, props, target);
}
void ConvolutionState::process(const size_t samplesToDo,
const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut)
{
if(mFilter)
mFilter->process(samplesToDo, samplesIn, samplesOut);
}
void ConvolutionEffect_setParami(EffectProps* /*props*/, ALenum param, int /*val*/)
{
switch(param)
{
default:
throw effect_exception{AL_INVALID_ENUM, "Invalid null effect integer property 0x%04x",
param};
}
}
void ConvolutionEffect_setParamiv(EffectProps *props, ALenum param, const int *vals)
{
switch(param)
{
default:
ConvolutionEffect_setParami(props, param, vals[0]);
}
}
void ConvolutionEffect_setParamf(EffectProps* /*props*/, ALenum param, float /*val*/)
{
switch(param)
{
default:
throw effect_exception{AL_INVALID_ENUM, "Invalid null effect float property 0x%04x",
param};
}
}
void ConvolutionEffect_setParamfv(EffectProps *props, ALenum param, const float *vals)
{
switch(param)
{
default:
ConvolutionEffect_setParamf(props, param, vals[0]);
}
}
void ConvolutionEffect_getParami(const EffectProps* /*props*/, ALenum param, int* /*val*/)
{
switch(param)
{
default:
throw effect_exception{AL_INVALID_ENUM, "Invalid null effect integer property 0x%04x",
param};
}
}
void ConvolutionEffect_getParamiv(const EffectProps *props, ALenum param, int *vals)
{
switch(param)
{
default:
ConvolutionEffect_getParami(props, param, vals);
}
}
void ConvolutionEffect_getParamf(const EffectProps* /*props*/, ALenum param, float* /*val*/)
{
switch(param)
{
default:
throw effect_exception{AL_INVALID_ENUM, "Invalid null effect float property 0x%04x",
param};
}
}
void ConvolutionEffect_getParamfv(const EffectProps *props, ALenum param, float *vals)
{
switch(param)
{
default:
ConvolutionEffect_getParamf(props, param, vals);
}
}
DEFINE_ALEFFECT_VTABLE(ConvolutionEffect);
struct ConvolutionStateFactory final : public EffectStateFactory {
EffectState *create() override;
EffectProps getDefaultProps() const noexcept override;
const EffectVtable *getEffectVtable() const noexcept override;
};
/* Creates EffectState objects of the appropriate type. */
EffectState *ConvolutionStateFactory::create()
{ return new ConvolutionState{}; }
/* Returns an ALeffectProps initialized with this effect type's default
* property values.
*/
EffectProps ConvolutionStateFactory::getDefaultProps() const noexcept
{
EffectProps props{};
return props;
}
/* Returns a pointer to this effect type's global set/get vtable. */
const EffectVtable *ConvolutionStateFactory::getEffectVtable() const noexcept
{ return &ConvolutionEffect_vtable; }
} // namespace
EffectStateFactory *ConvolutionStateFactory_getFactory()
{
static ConvolutionStateFactory ConvolutionFactory{};
return &ConvolutionFactory;
}