From 82efb29e2ac3d48892b05e1c4d23524d35da69c7 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Sat, 30 Dec 2023 06:27:33 -0800
Subject: Clean up some ugly pointer manipulation in the limiter
---
core/mastering.cpp | 95 ++++++++++++++++++++++++++++--------------------------
core/mastering.h | 3 +-
2 files changed, 51 insertions(+), 47 deletions(-)
(limited to 'core')
diff --git a/core/mastering.cpp b/core/mastering.cpp
index 5fecdb3f..9bb4c053 100644
--- a/core/mastering.cpp
+++ b/core/mastering.cpp
@@ -60,14 +60,16 @@ float UpdateSlidingHold(SlidingHold *Hold, const uint i, const float in)
}
else
{
- do {
+ auto findLowerIndex = [&lowerIndex,in,values]() noexcept -> bool
+ {
do {
if(!(in >= values[lowerIndex]))
- goto found_place;
+ return true;
} while(lowerIndex--);
+ return false;
+ };
+ while(!findLowerIndex())
lowerIndex = mask;
- } while(true);
- found_place:
lowerIndex = (lowerIndex + 1) & mask;
values[lowerIndex] = in;
@@ -82,15 +84,16 @@ float UpdateSlidingHold(SlidingHold *Hold, const uint i, const float in)
void ShiftSlidingHold(SlidingHold *Hold, const uint n)
{
- auto exp_begin = std::begin(Hold->mExpiries) + Hold->mUpperIndex;
- auto exp_last = std::begin(Hold->mExpiries) + Hold->mLowerIndex;
- if(exp_last-exp_begin < 0)
+ auto exp_upper = Hold->mExpiries.begin() + Hold->mUpperIndex;
+ if(Hold->mLowerIndex < Hold->mUpperIndex)
{
- std::transform(exp_begin, std::end(Hold->mExpiries), exp_begin,
- [n](uint e){ return e - n; });
- exp_begin = std::begin(Hold->mExpiries);
+ std::transform(exp_upper, Hold->mExpiries.end(), exp_upper,
+ [n](const uint e) noexcept { return e - n; });
+ exp_upper = Hold->mExpiries.begin();
}
- std::transform(exp_begin, exp_last+1, exp_begin, [n](uint e){ return e - n; });
+ const auto exp_lower = Hold->mExpiries.begin() + Hold->mLowerIndex;
+ std::transform(exp_upper, exp_lower+1, exp_upper,
+ [n](const uint e) noexcept { return e - n; });
}
@@ -104,7 +107,7 @@ void LinkChannels(Compressor *Comp, const uint SamplesToDo, const FloatBufferLin
ASSUME(SamplesToDo > 0);
ASSUME(numChans > 0);
- auto side_begin = std::begin(Comp->mSideChain) + Comp->mLookAhead;
+ const auto side_begin = Comp->mSideChain.begin() + Comp->mLookAhead;
std::fill(side_begin, side_begin+SamplesToDo, 0.0f);
auto fill_max = [SamplesToDo,side_begin](const FloatBufferLine &input) -> void
@@ -132,14 +135,14 @@ void CrestDetector(Compressor *Comp, const uint SamplesToDo)
auto calc_crest = [&y2_rms,&y2_peak,a_crest](const float x_abs) noexcept -> float
{
- const float x2{clampf(x_abs * x_abs, 0.000001f, 1000000.0f)};
+ const float x2{clampf(x_abs*x_abs, 0.000001f, 1000000.0f)};
- y2_peak = maxf(x2, lerpf(x2, y2_peak, a_crest));
+ y2_peak = std::max(x2, lerpf(x2, y2_peak, a_crest));
y2_rms = lerpf(x2, y2_rms, a_crest);
return y2_peak / y2_rms;
};
- auto side_begin = std::begin(Comp->mSideChain) + Comp->mLookAhead;
- std::transform(side_begin, side_begin+SamplesToDo, std::begin(Comp->mCrestFactor), calc_crest);
+ const auto side_begin = Comp->mSideChain.begin() + Comp->mLookAhead;
+ std::transform(side_begin, side_begin+SamplesToDo, Comp->mCrestFactor.begin(), calc_crest);
Comp->mLastPeakSq = y2_peak;
Comp->mLastRmsSq = y2_rms;
@@ -153,10 +156,10 @@ void PeakDetector(Compressor *Comp, const uint SamplesToDo)
{
ASSUME(SamplesToDo > 0);
- /* Clamp the minimum amplitude to near-zero and convert to logarithm. */
- auto side_begin = std::begin(Comp->mSideChain) + Comp->mLookAhead;
+ /* Clamp the minimum amplitude to near-zero and convert to logarithmic. */
+ const auto side_begin = Comp->mSideChain.begin() + Comp->mLookAhead;
std::transform(side_begin, side_begin+SamplesToDo, side_begin,
- [](float s) { return std::log(maxf(0.000001f, s)); });
+ [](float s) { return std::log(std::max(0.000001f, s)); });
}
/* An optional hold can be used to extend the peak detector so it can more
@@ -171,10 +174,10 @@ void PeakHoldDetector(Compressor *Comp, const uint SamplesToDo)
uint i{0};
auto detect_peak = [&i,hold](const float x_abs) -> float
{
- const float x_G{std::log(maxf(0.000001f, x_abs))};
+ const float x_G{std::log(std::max(0.000001f, x_abs))};
return UpdateSlidingHold(hold, i++, x_G);
};
- auto side_begin = std::begin(Comp->mSideChain) + Comp->mLookAhead;
+ auto side_begin = Comp->mSideChain.begin() + Comp->mLookAhead;
std::transform(side_begin, side_begin+SamplesToDo, side_begin, detect_peak);
ShiftSlidingHold(hold, SamplesToDo);
@@ -192,14 +195,14 @@ void GainCompressor(Compressor *Comp, const uint SamplesToDo)
const bool autoRelease{Comp->mAuto.Release};
const bool autoPostGain{Comp->mAuto.PostGain};
const bool autoDeclip{Comp->mAuto.Declip};
- const uint lookAhead{Comp->mLookAhead};
const float threshold{Comp->mThreshold};
const float slope{Comp->mSlope};
const float attack{Comp->mAttack};
const float release{Comp->mRelease};
const float c_est{Comp->mGainEstimate};
const float a_adp{Comp->mAdaptCoeff};
- const float *crestFactor{Comp->mCrestFactor.data()};
+ auto lookAhead = Comp->mSideChain.cbegin() + Comp->mLookAhead;
+ auto crestFactor = Comp->mCrestFactor.cbegin();
float postGain{Comp->mPostGain};
float knee{Comp->mKnee};
float t_att{attack};
@@ -212,19 +215,19 @@ void GainCompressor(Compressor *Comp, const uint SamplesToDo)
ASSUME(SamplesToDo > 0);
- for(float &sideChain : al::span{Comp->mSideChain.data(), SamplesToDo})
+ auto process = [&](const float input) -> float
{
if(autoKnee)
- knee = maxf(0.0f, 2.5f * (c_dev + c_est));
+ knee = std::max(0.0f, 2.5f * (c_dev + c_est));
const float knee_h{0.5f * knee};
/* This is the gain computer. It applies a static compression curve
* to the control signal.
*/
- const float x_over{std::addressof(sideChain)[lookAhead] - threshold};
+ const float x_over{*(lookAhead++) - threshold};
const float y_G{
(x_over <= -knee_h) ? 0.0f :
- (std::fabs(x_over) < knee_h) ? (x_over + knee_h) * (x_over + knee_h) / (2.0f * knee) :
+ (std::fabs(x_over) < knee_h) ? (x_over+knee_h) * (x_over+knee_h) / (2.0f * knee) :
x_over};
const float y2_crest{*(crestFactor++)};
@@ -244,7 +247,7 @@ void GainCompressor(Compressor *Comp, const uint SamplesToDo)
* above to compensate for the chained operating mode.
*/
const float x_L{-slope * y_G};
- y_1 = maxf(x_L, lerpf(x_L, y_1, a_rel));
+ y_1 = std::max(x_L, lerpf(x_L, y_1, a_rel));
y_L = lerpf(y_1, y_L, a_att);
/* Knee width and make-up gain automation make use of a smoothed
@@ -263,13 +266,15 @@ void GainCompressor(Compressor *Comp, const uint SamplesToDo)
* same output level.
*/
if(autoDeclip)
- c_dev = maxf(c_dev, sideChain - y_L - threshold - c_est);
+ c_dev = std::max(c_dev, input - y_L - threshold - c_est);
postGain = -(c_dev + c_est);
}
- sideChain = std::exp(postGain - y_L);
- }
+ return std::exp(postGain - y_L);
+ };
+ auto sideChain = al::span{Comp->mSideChain}.first(SamplesToDo);
+ std::transform(sideChain.begin(), sideChain.end(), sideChain.begin(), process);
Comp->mLastRelease = y_1;
Comp->mLastAttack = y_L;
@@ -326,7 +331,7 @@ std::unique_ptr<Compressor> Compressor::Create(const size_t NumChans, const floa
size_t size{sizeof(Compressor)};
if(lookAhead > 0)
{
- size += sizeof(*Compressor::mDelay) * NumChans;
+ size += sizeof(Compressor::mDelay[0]) * NumChans;
/* The sliding hold implementation doesn't handle a length of 1. A 1-
* sample hold is useless anyway, it would only ever give back what was
* just given to it.
@@ -347,12 +352,12 @@ std::unique_ptr<Compressor> Compressor::Create(const size_t NumChans, const floa
Comp->mAuto.Declip = AutoPostGain && AutoDeclip;
Comp->mLookAhead = lookAhead;
Comp->mPreGain = std::pow(10.0f, PreGainDb / 20.0f);
- Comp->mPostGain = PostGainDb * std::log(10.0f) / 20.0f;
- Comp->mThreshold = ThresholdDb * std::log(10.0f) / 20.0f;
- Comp->mSlope = 1.0f / maxf(1.0f, Ratio) - 1.0f;
- Comp->mKnee = maxf(0.0f, KneeDb * std::log(10.0f) / 20.0f);
- Comp->mAttack = maxf(1.0f, AttackTime * SampleRate);
- Comp->mRelease = maxf(1.0f, ReleaseTime * SampleRate);
+ Comp->mPostGain = std::log(10.0f)/20.0f * PostGainDb;
+ Comp->mThreshold = std::log(10.0f)/20.0f * ThresholdDb;
+ Comp->mSlope = 1.0f / std::max(1.0f, Ratio) - 1.0f;
+ Comp->mKnee = std::max(0.0f, std::log(10.0f)/20.0f * KneeDb);
+ Comp->mAttack = std::max(1.0f, AttackTime * SampleRate);
+ Comp->mRelease = std::max(1.0f, ReleaseTime * SampleRate);
/* Knee width automation actually treats the compressor as a limiter. By
* varying the knee width, it can effectively be seen as applying
@@ -369,11 +374,11 @@ std::unique_ptr<Compressor> Compressor::Create(const size_t NumChans, const floa
Comp->mHold->mValues[0] = -std::numeric_limits<float>::infinity();
Comp->mHold->mExpiries[0] = hold;
Comp->mHold->mLength = hold;
- Comp->mDelay = reinterpret_cast<FloatBufferLine*>(Comp->mHold + 1);
+ Comp->mDelay = {reinterpret_cast<FloatBufferLine*>(Comp->mHold + 1), NumChans};
}
else
- Comp->mDelay = reinterpret_cast<FloatBufferLine*>(Comp.get() + 1);
- std::uninitialized_fill_n(Comp->mDelay, NumChans, FloatBufferLine{});
+ Comp->mDelay = {reinterpret_cast<FloatBufferLine*>(Comp.get() + 1), NumChans};
+ std::uninitialized_fill(Comp->mDelay.begin(), Comp->mDelay.end(), FloatBufferLine{});
}
Comp->mCrestCoeff = std::exp(-1.0f / (0.200f * SampleRate)); // 200ms
@@ -388,9 +393,7 @@ Compressor::~Compressor()
if(mHold)
std::destroy_at(mHold);
mHold = nullptr;
- if(mDelay)
- std::destroy_n(mDelay, mNumChans);
- mDelay = nullptr;
+ std::destroy(mDelay.begin(), mDelay.end());
}
@@ -408,7 +411,7 @@ void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
{
float *buffer{al::assume_aligned<16>(input.data())};
std::transform(buffer, buffer+SamplesToDo, buffer,
- [preGain](float s) { return s * preGain; });
+ [preGain](const float s) noexcept { return s * preGain; });
};
std::for_each(OutBuffer, OutBuffer+numChans, apply_gain);
}
@@ -425,7 +428,7 @@ void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
GainCompressor(this, SamplesToDo);
- if(mDelay)
+ if(!mDelay.empty())
SignalDelay(this, SamplesToDo, OutBuffer);
const auto sideChain = al::span{mSideChain};
diff --git a/core/mastering.h b/core/mastering.h
index 8baea601..4a3b59cf 100644
--- a/core/mastering.h
+++ b/core/mastering.h
@@ -6,6 +6,7 @@
#include "almalloc.h"
#include "alnumeric.h"
+#include "alspan.h"
#include "bufferline.h"
struct SlidingHold;
@@ -50,7 +51,7 @@ struct Compressor {
alignas(16) std::array<float,BufferLineSize> mCrestFactor{};
SlidingHold *mHold{nullptr};
- FloatBufferLine *mDelay{nullptr};
+ al::span<FloatBufferLine> mDelay;
float mCrestCoeff{0.0f};
float mGainEstimate{0.0f};
--
cgit v1.2.3