diff options
Diffstat (limited to 'utils/makemhr')
| -rw-r--r-- | utils/makemhr/makemhr.cpp | 122 |
1 files changed, 93 insertions, 29 deletions
diff --git a/utils/makemhr/makemhr.cpp b/utils/makemhr/makemhr.cpp index c4b55d23..3ef2a9ef 100644 --- a/utils/makemhr/makemhr.cpp +++ b/utils/makemhr/makemhr.cpp @@ -523,6 +523,94 @@ static int StoreMhr(const HrirDataT *hData, const char *filename) *** HRTF processing *** ***********************/ +// Resamples the HRIRs for use at the given sampling rate. +static void ResampleHrirs(const uint rate, HrirDataT *hData) +{ + struct Resampler { + const double scale; + const size_t m; + double *const resampled; + + /* Resampling from a lower rate to a higher rate. This likely only + * works properly when 1 <= scale <= 2. + */ + void upsample(double *ir) const + { + std::fill_n(resampled, m, 0.0); + resampled[0] = ir[0]; + for(size_t in{1};in < m;++in) + { + const auto offset = static_cast<double>(in) / scale; + const auto out = static_cast<size_t>(offset); + + const double a{offset - static_cast<double>(out)}; + if(out == m-1) + resampled[out] += ir[in]*(1.0-a); + else + { + resampled[out ] += ir[in]*(1.0-a); + resampled[out+1] += ir[in]*a; + } + } + /* This should probably be rescaled according to the scale, however + * it'll all be normalized in the end so a constant scalar is fine + * to leave. + */ + std::copy_n(resampled, m, ir); + } + + /* Resampling from a higher rate to a lower rate. This likely only + * works properly when 0.5 <= scale <= 1.0. + */ + void downsample(double *ir) const + { + std::fill_n(resampled, m, 0.0); + resampled[0] = ir[0]; + for(size_t out{1};out < m;++out) + { + const auto offset = static_cast<double>(out) * scale; + const auto in = static_cast<size_t>(offset); + + const double a{offset - static_cast<double>(in)}; + if(in == m-1) + resampled[out] = ir[in]*(1.0-a); + else + resampled[out] = ir[in]*(1.0-a) + ir[in+1]*a; + } + std::copy_n(resampled, m, ir); + } + }; + + while(rate > hData->mIrRate*2) + ResampleHrirs(hData->mIrRate*2, hData); + while(rate < (hData->mIrRate+1)/2) + ResampleHrirs((hData->mIrRate+1)/2, hData); + + const auto scale = static_cast<double>(rate) / hData->mIrRate; + const size_t m{hData->mFftSize/2u + 1u}; + auto resampled = std::vector<double>(m); + + const Resampler resampler{scale, m, resampled.data()}; + auto do_resample = std::bind( + std::mem_fn((scale > 1.0) ? &Resampler::upsample : &Resampler::downsample), &resampler, + _1); + + const uint channels{(hData->mChannelType == CT_STEREO) ? 2u : 1u}; + for(uint fi{0};fi < hData->mFdCount;++fi) + { + for(uint ei{hData->mFds[fi].mEvStart};ei < hData->mFds[fi].mEvCount;++ei) + { + for(uint ai{0};ai < hData->mFds[fi].mEvs[ei].mAzCount;++ai) + { + HrirAzT *azd = &hData->mFds[fi].mEvs[ei].mAzs[ai]; + for(uint ti{0};ti < channels;++ti) + do_resample(azd->mIrs[ti]); + } + } + } + hData->mIrRate = rate; +} + /* Balances the maximum HRIR magnitudes of multi-field data sets by * independently normalizing each field in relation to the overall maximum. * This is done to ignore distance attenuation. @@ -818,30 +906,6 @@ static void ReconstructHrirs(const HrirDataT *hData) if(thrd1.joinable()) thrd1.join(); } -// Resamples the HRIRs for use at the given sampling rate. -static void ResampleHrirs(const uint rate, HrirDataT *hData) -{ - uint channels = (hData->mChannelType == CT_STEREO) ? 2 : 1; - uint n = hData->mIrPoints; - uint ti, fi, ei, ai; - PPhaseResampler rs; - - rs.init(hData->mIrRate, rate); - for(fi = 0;fi < hData->mFdCount;fi++) - { - for(ei = hData->mFds[fi].mEvStart;ei < hData->mFds[fi].mEvCount;ei++) - { - for(ai = 0;ai < hData->mFds[fi].mEvs[ei].mAzCount;ai++) - { - HrirAzT *azd = &hData->mFds[fi].mEvs[ei].mAzs[ai]; - for(ti = 0;ti < channels;ti++) - rs.process(n, azd->mIrs[ti], n, azd->mIrs[ti]); - } - } - } - hData->mIrRate = rate; -} - /* Given field and elevation indices and an azimuth, calculate the indices of * the two HRIRs that bound the coordinate along with a factor for * calculating the continuous HRIR using interpolation. @@ -1360,6 +1424,11 @@ static int ProcessDefinition(const char *inName, const uint outRate, const Chann } } + if(outRate != 0 && outRate != hData.mIrRate) + { + fprintf(stdout, "Resampling HRIRs...\n"); + ResampleHrirs(outRate, &hData); + } if(equalize) { uint c{(hData.mChannelType == CT_STEREO) ? 2u : 1u}; @@ -1378,11 +1447,6 @@ static int ProcessDefinition(const char *inName, const uint outRate, const Chann } fprintf(stdout, "Performing minimum phase reconstruction...\n"); ReconstructHrirs(&hData); - if(outRate != 0 && outRate != hData.mIrRate) - { - fprintf(stdout, "Resampling HRIRs...\n"); - ResampleHrirs(outRate, &hData); - } fprintf(stdout, "Truncating minimum-phase HRIRs...\n"); hData.mIrPoints = truncSize; fprintf(stdout, "Synthesizing missing elevations...\n"); |