diff options
| -rw-r--r-- | alc/hrtf.cpp | 105 |
1 files changed, 13 insertions, 92 deletions
diff --git a/alc/hrtf.cpp b/alc/hrtf.cpp index f1e1a86b..05803865 100644 --- a/alc/hrtf.cpp +++ b/alc/hrtf.cpp @@ -289,13 +289,7 @@ void DirectHrtfState::build(const HrtfStore *Hrtf, const al::span<const AngularP ALuint ldelay, rdelay; }; - /* Set this to true for dual-band HRTF processing. May require better - * calculation of the new IR length to deal with the head and tail - * generated by the HF scaling. - */ - constexpr bool DualBand{false}; const double xover_norm{400.0 / Hrtf->sampleRate}; - for(size_t i{0};i < mChannels.size();++i) { const size_t order{AmbiIndex::OrderFromChannel[i]}; @@ -303,8 +297,7 @@ void DirectHrtfState::build(const HrtfStore *Hrtf, const al::span<const AngularP mChannels[i].mHfScale = AmbiOrderHFGain[order]; } - ALuint min_delay{HRTF_HISTORY_LENGTH*HRIR_DELAY_FRACONE}; - ALuint max_delay{0}; + ALuint min_delay{HRTF_HISTORY_LENGTH*HRIR_DELAY_FRACONE}, max_delay{0}; al::vector<ImpulseResponse> impres; impres.reserve(AmbiPoints.size()); auto calc_res = [Hrtf,&max_delay,&min_delay](const AngularPoint &pt) -> ImpulseResponse { @@ -345,93 +338,25 @@ void DirectHrtfState::build(const HrtfStore *Hrtf, const al::span<const AngularP auto hrir_delay_round = [](const ALuint d) noexcept -> ALuint { return (d+HRIR_DELAY_FRACHALF) >> HRIR_DELAY_FRACBITS; }; - /* For dual-band processing, add a 16-sample delay to compensate for the HF - * scale on the minimum-phase response. - */ - constexpr ALuint base_delay{DualBand ? 16 : 0}; - BandSplitterR<double> splitter{xover_norm}; - auto tmpres = al::vector<std::array<double2,HRIR_LENGTH>>(mChannels.size()); - auto tmpflt = al::vector<std::array<double,HRIR_LENGTH*4>>(3); - const al::span<double,HRIR_LENGTH*4> tempir{tmpflt[2]}; for(size_t c{0u};c < AmbiPoints.size();++c) { const HrirArray &hrir{impres[c].hrir}; - const ALuint ldelay{hrir_delay_round(impres[c].ldelay-min_delay) + base_delay}; - const ALuint rdelay{hrir_delay_round(impres[c].rdelay-min_delay) + base_delay}; - - if /*constexpr*/(!DualBand) - { - for(size_t i{0u};i < mChannels.size();++i) - { - const double mult{AmbiMatrix[c][i]}; - const size_t numirs{HRIR_LENGTH - maxz(ldelay, rdelay)}; - size_t lidx{ldelay}, ridx{rdelay}; - for(size_t j{0};j < numirs;++j) - { - tmpres[i][lidx++][0] += hrir[j][0] * mult; - tmpres[i][ridx++][1] += hrir[j][1] * mult; - } - } - continue; - } - - /* For dual-band processing, the HRIR needs to be split into low and - * high frequency responses. The band-splitter alone creates frequency- - * dependent phase-shifts, which is not ideal. To counteract it, - * combine it with a backwards phase-shift. - */ - - /* Load the (left) HRIR backwards, into a temp buffer with padding. */ - std::fill(tempir.begin(), tempir.end(), 0.0); - std::transform(hrir.crbegin(), hrir.crend(), tempir.begin(), - [](const float2 &ir) noexcept -> double { return ir[0]; }); - - /* Apply the all-pass on the reversed signal and reverse the resulting - * sample array. This produces the forward response with a backwards - * phase-shift (+n degrees becomes -n degrees). - */ - splitter.applyAllpass(tempir); - std::reverse(tempir.begin(), tempir.end()); - - /* Now apply the band-splitter. This applies the normal phase-shift, - * which cancels out with the backwards phase-shift to get the original - * phase on the split signal. - */ - splitter.clear(); - splitter.process(tempir, tmpflt[0].data(), tmpflt[1].data()); - - /* Apply left ear response with delay and HF scale. */ - for(size_t i{0u};i < mChannels.size();++i) - { - const double mult{AmbiMatrix[c][i]}; - const double hfgain{AmbiOrderHFGain[AmbiIndex::OrderFromChannel[i]]}; - size_t j{tmpflt[0].size()-HRIR_LENGTH - ldelay}; - for(size_t lidx{0};lidx < HRIR_LENGTH;++lidx,++j) - tmpres[i][lidx][0] += (tmpflt[0][j]*hfgain + tmpflt[1][j]) * mult; - } - - /* Now run the same process on the right HRIR. */ - std::fill(tempir.begin(), tempir.end(), 0.0); - std::transform(hrir.crbegin(), hrir.crend(), tempir.begin(), - [](const float2 &ir) noexcept -> double { return ir[1]; }); - - splitter.applyAllpass(tempir); - std::reverse(tempir.begin(), tempir.end()); - - splitter.clear(); - splitter.process(tempir, tmpflt[0].data(), tmpflt[1].data()); + const ALuint ldelay{hrir_delay_round(impres[c].ldelay - min_delay)}; + const ALuint rdelay{hrir_delay_round(impres[c].rdelay - min_delay)}; for(size_t i{0u};i < mChannels.size();++i) { const double mult{AmbiMatrix[c][i]}; - const double hfgain{AmbiOrderHFGain[AmbiIndex::OrderFromChannel[i]]}; - size_t j{tmpflt[0].size()-HRIR_LENGTH - rdelay}; - for(size_t ridx{0};ridx < HRIR_LENGTH;++ridx,++j) - tmpres[i][ridx][1] += (tmpflt[0][j]*hfgain + tmpflt[1][j]) * mult; + const size_t numirs{HRIR_LENGTH - maxz(ldelay, rdelay)}; + size_t lidx{ldelay}, ridx{rdelay}; + for(size_t j{0};j < numirs;++j) + { + tmpres[i][lidx++][0] += hrir[j][0] * mult; + tmpres[i][ridx++][1] += hrir[j][1] * mult; + } } } - tmpflt.clear(); impres.clear(); for(size_t i{0u};i < mChannels.size();++i) @@ -443,14 +368,10 @@ void DirectHrtfState::build(const HrtfStore *Hrtf, const al::span<const AngularP } tmpres.clear(); - max_delay -= min_delay; - /* Increase the IR size by double the base delay with dual-band processing - * to account for the head and tail from the HF response scale. - */ - const ALuint irsize{minu(Hrtf->irSize + base_delay*2, HRIR_LENGTH)}; - const ALuint max_length{minu(hrir_delay_round(max_delay) + irsize, HRIR_LENGTH)}; + max_delay = hrir_delay_round(max_delay - min_delay); + const ALuint max_length{minu(max_delay + Hrtf->irSize, HRIR_LENGTH)}; - TRACE("Skipped delay: %.2f, max delay: %.2f, new FIR length: %u\n", + TRACE("Skipped delay: %.2f, new max delay: %.2f, FIR length: %u\n", min_delay/double{HRIR_DELAY_FRACONE}, max_delay/double{HRIR_DELAY_FRACONE}, max_length); mIrSize = max_length; |