diff options
| -rw-r--r-- | core/bformatdec.cpp | 30 | ||||
| -rw-r--r-- | core/filters/splitter.cpp | 4 | ||||
| -rw-r--r-- | core/filters/splitter.h | 11 |
3 files changed, 21 insertions, 24 deletions
diff --git a/core/bformatdec.cpp b/core/bformatdec.cpp index 1ad46f95..606093c0 100644 --- a/core/bformatdec.cpp +++ b/core/bformatdec.cpp @@ -133,31 +133,25 @@ void BFormatDec::processStablize(const al::span<FloatBufferLine> OutBuffer, for(size_t i{0};i < SamplesToDo;++i) side[FrontStablizer::DelayLength+i] += OutBuffer[lidx][i] - OutBuffer[ridx][i]; - /* Combine the delayed mid signal with the decoded mid signal. Note that - * the samples are stored and combined in reverse, so the newest samples - * are at the front and the oldest at the back. - */ - al::span<float> tmpbuf{mStablizer->TempBuf.data(), SamplesToDo+FrontStablizer::DelayLength}; - auto tmpiter = tmpbuf.begin() + SamplesToDo; - std::copy(mStablizer->MidDelay.cbegin(), mStablizer->MidDelay.cend(), tmpiter); - for(size_t i{0};i < SamplesToDo;++i) - *--tmpiter = OutBuffer[lidx][i] + OutBuffer[ridx][i]; + /* Combine the delayed mid signal with the decoded mid signal. */ + float *tmpbuf{mStablizer->TempBuf.data()}; + auto tmpiter = std::copy(mStablizer->MidDelay.cbegin(), mStablizer->MidDelay.cend(), tmpbuf); + for(size_t i{0};i < SamplesToDo;++i,++tmpiter) + *tmpiter = OutBuffer[lidx][i] + OutBuffer[ridx][i]; /* Save the newest samples for next time. */ - std::copy_n(tmpbuf.cbegin(), mStablizer->MidDelay.size(), mStablizer->MidDelay.begin()); + std::copy_n(tmpbuf+SamplesToDo, mStablizer->MidDelay.size(), mStablizer->MidDelay.begin()); - /* Apply an all-pass on the reversed signal, then reverse the samples to - * get the forward signal with a reversed phase shift. The future samples - * are included with the all-pass to reduce the error in the output - * samples (the smaller the delay, the more error is introduced). + /* Apply an all-pass on the signal in reverse. The future samples are + * included with the all-pass to reduce the error in the output samples + * (the smaller the delay, the more error is introduced). */ - mStablizer->MidFilter.applyAllpass(tmpbuf); - tmpbuf = tmpbuf.subspan<FrontStablizer::DelayLength>(); - std::reverse(tmpbuf.begin(), tmpbuf.end()); + mStablizer->MidFilter.applyAllpassRev({tmpbuf, SamplesToDo+FrontStablizer::DelayLength}); /* Now apply the band-splitter, combining its phase shift with the reversed * phase shift, restoring the original phase on the split signal. */ - mStablizer->MidFilter.process(tmpbuf, mStablizer->MidHF.data(), mStablizer->MidLF.data()); + mStablizer->MidFilter.process({tmpbuf, SamplesToDo}, mStablizer->MidHF.data(), + mStablizer->MidLF.data()); /* This pans the separate low- and high-frequency signals between being on * the center channel and the left+right channels. The low-frequency signal diff --git a/core/filters/splitter.cpp b/core/filters/splitter.cpp index 19f7646a..e7f03756 100644 --- a/core/filters/splitter.cpp +++ b/core/filters/splitter.cpp @@ -160,7 +160,7 @@ void BandSplitterR<Real>::processScale(const al::span<Real> samples, const Real } template<typename Real> -void BandSplitterR<Real>::applyAllpass(const al::span<Real> samples) const +void BandSplitterR<Real>::applyAllpassRev(const al::span<Real> samples) const { const Real coeff{mCoeff}; Real z1{0.0f}; @@ -170,7 +170,7 @@ void BandSplitterR<Real>::applyAllpass(const al::span<Real> samples) const z1 = in - out*coeff; return out; }; - std::transform(samples.begin(), samples.end(), samples.begin(), proc_sample); + std::transform(samples.rbegin(), samples.rend(), samples.rbegin(), proc_sample); } diff --git a/core/filters/splitter.h b/core/filters/splitter.h index 41805c70..fa15bd50 100644 --- a/core/filters/splitter.h +++ b/core/filters/splitter.h @@ -29,11 +29,14 @@ public: void processHfScale(const al::span<Real> samples, const Real hfscale); void processScale(const al::span<Real> samples, const Real hfscale, const Real lfscale); - /* The all-pass portion of the band splitter. Applies the same phase shift - * without splitting the signal. Note that each use of this method is - * indepedent, it does not track history between calls. + /** + * The all-pass portion of the band splitter. Applies the same phase shift + * without splitting the signal, in reverse. It starts from the back of the + * span and works toward the front, creating a phase shift of -n degrees + * instead of +n. Note that each use of this method is indepedent, it does + * not track history between calls. */ - void applyAllpass(const al::span<Real> samples) const; + void applyAllpassRev(const al::span<Real> samples) const; }; using BandSplitter = BandSplitterR<float>; |