### Namespace and Compatibility Setup

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Standard library imports and compatibility workarounds for pre-C++11 compilers.

```cpp
namespace avir {

using std :: memcpy;
using std :: memset;
using std :: fabs;
using std :: floor;
using std :: ceil;
using std :: sin;
using std :: cos;
using std :: size_t;

#if __cplusplus >= 201103L

 using std :: intptr_t;
 using std :: uintptr_t;

#else // __cplusplus >= 201103L

 // Workaround for pre-C++11 compilers. `nullptr` is a keyword, and not a
 // macro, but check if such workaround is already in place.

 #if !defined( nullptr )
 #define nullptr NULL
 #define LANCIR_NULLPTR
 #endif // !defined( nullptr )

#endif // __cplusplus >= 201103L
```

--------------------------------

### startAllWorkloads()

Source: https://www.voxengo.com/public/avir/Documentation/a00056.html

Starts all workloads associated with threads previously added.

```APIDOC
## void avir::CImageResizerThreadPool::startAllWorkloads()

### Description
Starts all workloads associated with threads previously added via the addWorkload() function. This function performs the necessary memory barrier operations to ensure thread synchronization.
```

--------------------------------

### Resize Macros

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Preprocessor macros for handling loop setup and teardown in resizing operations.

```cpp
#define LANCIR_LF_PRE \
const CResizePos* const rpe = rp + DstLen; \
while( rp != rpe ) \
{ \
const float* flt = rp -> flt; \
const float* ip; \
if( UseSP ) \
{ \
ip = (const float*) ( (intptr_t) sp + rp -> spo ); \
} \
else \
{ \
ip = (const float*) rp -> spo; \
}
```

```cpp
#define LANCIR_LF_POST \
op += opinc; \
rp++; \
}
```

--------------------------------

### startAllWorkloads

Source: https://www.voxengo.com/public/avir/Documentation/a00056.html

Starts all workloads associated with threads previously added to the pool.

```APIDOC
## void startAllWorkloads()

### Description
Starts all workloads associated with threads previously added via the addWorkload() function. Each thread will execute its workload's process() function.
```

--------------------------------

### CSineGen Constructor

Source: https://www.voxengo.com/public/avir/Documentation/a00032.html

Initializes the sine signal generator with a specific increment and starting phase.

```APIDOC
## CSineGen(const double si, const double ph)

### Description
Initializes the sine signal generator. This generator uses an efficient oscillator instead of the standard sin() function.

### Parameters
- **si** (double) - Sine function increment, in radians.
- **ph** (double) - Starting phase, in radians. Add 0.5 * AVIR_PI for cosine function.
```

--------------------------------

### init()

Source: https://www.voxengo.com/public/avir/Documentation/a00120.html

Initializes the ditherer object with scanline length, resizing variables, truncation multiplier, and peak output value.

```APIDOC
## void init(const int aLen, const CImageResizerVars &aVars, const double aTrMul, const double aPkOut)

### Description
Initializes the ditherer object.

### Parameters
- **aLen** (int) - Scanline length in pixels to process.
- **aVars** (CImageResizerVars) - Image resizing-related variables.
- **aTrMul** (double) - Bit-depth truncation multiplier. 1 - no additional truncation.
- **aPkOut** (double) - Peak output value allowed.
```

--------------------------------

### void init(const int aLen, const CImageResizerVars &aVars, const double aTrMul, const double aPkOut)

Source: https://www.voxengo.com/public/avir/Documentation/a00152.html

Initializes the ditherer object with scanline length, resizing variables, and dithering parameters.

```APIDOC
## void init(const int aLen, const CImageResizerVars &aVars, const double aTrMul, const double aPkOut)

### Description
Initializes the ditherer object for processing.

### Parameters
- **aLen** (int) - Required - Scanline length in pixels to process.
- **aVars** (CImageResizerVars &) - Required - Image resizing-related variables.
- **aTrMul** (double) - Required - Bit-depth truncation multiplier (1 indicates no additional truncation).
- **aPkOut** (double) - Required - Peak output value allowed.
```

--------------------------------

### void init(const int aLen, const CImageResizerVars &aVars, const double aTrMul, const double aPkOut)

Source: https://www.voxengo.com/public/avir/Documentation/a00148.html

Initializes the ditherer object with scanline length, resizing variables, and bit-depth parameters.

```APIDOC
## void init(const int aLen, const CImageResizerVars &aVars, const double aTrMul, const double aPkOut)

### Description
Initializes the ditherer object for processing.

### Parameters
- **aLen** (int) - Required - Scanline length in pixels to process.
- **aVars** (const CImageResizerVars &) - Required - Image resizing-related variables.
- **aTrMul** (double) - Required - Bit-depth truncation multiplier (1 means no additional truncation).
- **aPkOut** (double) - Required - Peak output value allowed.
```

--------------------------------

### init()

Source: https://www.voxengo.com/public/avir/Documentation/a00052.html

Initializes or builds the filter bank based on the provided parameters. If parameters match existing ones, the function performs no action.

```APIDOC
## void init(const int _ReqFracCount_, const int _ReqOrder_, const double _BaseLen_, const double _Cutoff_, const double _aWFAlpha_, const CFltBuffer & _aExtFilter_, const int _aAlignment_ = 0, const int _FltLenAlign_ = 1)

### Description
Initializes the filter bank. If the supplied parameters are equal to previously defined parameters, the function does nothing.

### Parameters
- **_ReqFracCount_** (int) - Required number of fractional delays in the filter bank (min 2).
- **_ReqOrder_** (int) - Required order of the interpolation polynomial (0 or 1).
- **_BaseLen_** (double) - Low-pass filter's base length in samples.
- **_Cutoff_** (double) - Normalized cutoff frequency [0; 1].
- **_aWFAlpha_** (double) - Peaked Cosine window function's Alpha parameter.
- **_aExtFilter_** (CFltBuffer) - External filter to apply to each fractional delay filter.
- **_aAlignment_** (int) - Memory alignment of the filter bank (power-of-2).
- **_FltLenAlign_** (int) - Filter's length alignment (power-of-2).
```

--------------------------------

### void resizeImage(const Tin *const _SrcBuf_, const int _SrcWidth_, const int _SrcHeight_, int _SrcScanlineSize_, Tout *const _NewBuf_, const int _NewWidth_, const int _NewHeight_, const int _ElCountIO_, const double _k_, CImageResizerVars *const _aVars_)

Source: https://www.voxengo.com/public/avir/Documentation/a00132.html

Resizes an image from a source buffer into a destination buffer using specified dimensions and scaling parameters.

```APIDOC
## void resizeImage(const Tin *const _SrcBuf_, const int _SrcWidth_, const int _SrcHeight_, int _SrcScanlineSize_, Tout *const _NewBuf_, const int _NewWidth_, const int _NewHeight_, const int _ElCountIO_, const double _k_, CImageResizerVars *const _aVars_)

### Description
Resizes the image based on provided dimensions and scaling factors. This function supports various input and output buffer types.

### Parameters
- **_SrcBuf_** (const Tin *const) - Source image buffer.
- **_SrcWidth_** (const int) - Source image width.
- **_SrcHeight_** (const int) - Source image height.
- **_SrcScanlineSize_** (int) - Physical size of source scanline in elements. If < 1, defaults to SrcWidth * ElCountIO.
- **_NewBuf_** (Tout *const) - Buffer to accept the resized image.
- **_NewWidth_** (const int) - New image width.
- **_NewHeight_** (const int) - New image height.
- **_ElCountIO_** (const int) - Number of elements (channels) per pixel (1-4).
- **_k_** (const double) - Resizing step. Downsizing factor if > 1.0; upsizing if < 1.0. Multiply by -1 to bypass default centering. 0 for automatic calculation.
- **_aVars_** (CImageResizerVars *const) - Pointer to variables structure. Optional, can be nullptr.

### Template Parameters
- **Tin** - Input buffer element type (uint8_t, uint16_t, float, double).
- **Tout** - Output buffer element type (uint8_t, uint16_t, float, double).
```

--------------------------------

### CImageResizerDithererDefDIL Class Initialization

Source: https://www.voxengo.com/public/avir/Documentation/a00008_source.html

Initialization method for the dithering class, setting up length and configuration variables.

```cpp
void init( const int aLen, const CImageResizerVars& aVars,
 const double aTrMul, const double aPkOut )
 {
 Len = aLen;
```

--------------------------------

### void avir::CDSPFIREQ::init

Source: https://www.voxengo.com/public/avir/Documentation/a00040.html

Initializes the CDSPFIREQ object with specific processing parameters including sample rate, filter length, and frequency band settings.

```APIDOC
## void avir::CDSPFIREQ::init(const double SampleRate, const double aFilterLength, const int aBandCount, const double MinFreq, const double MaxFreq, const bool IsLogBands, const double WFAlpha)

### Description
Initializes this object with the required parameters. The gain of frequencies beyond the MinFreq..MaxFreq range are controlled by the first and the last band's gain.

### Parameters
- **SampleRate** (double) - Processing sample rate (use 2 for image processing).
- **aFilterLength** (double) - Required filter length in samples (taps). The actual filter length is truncated to an integer value.
- **aBandCount** (int) - Number of band crossover points required to control, including bands at MinFreq and MaxFreq.
- **MinFreq** (double) - Minimal frequency that should be controlled.
- **MaxFreq** (double) - Maximal frequency that should be controlled.
- **IsLogBands** (bool) - true, if the bands should be spaced logarithmically.
- **WFAlpha** (double) - Peaked Cosine window function's Alpha parameter.
```

--------------------------------

### Prepare Input Buffer

Source: https://www.voxengo.com/public/avir/Documentation/a00008_source.html

Prepares the input buffer by replicating array boundaries based on prefix and suffix lengths.

```cpp
void prepareInBuf( fptype* Src ) const
{
if( IsUpsample || InPrefix + InSuffix == 0 )
{
return;
}

int j;

for( j = 0; j < Vars -> ElCount; j++ )
{
replicateArray( Src, 1, Src - InPrefix, InPrefix, 1 );
fptype* const Src2 = Src + InLen - 1;
replicateArray( Src2, 1, Src2 + 1, InSuffix, 1 );
Src += InElIncr;
}
}
```

--------------------------------

### Default Ditherer Initialization

Source: https://www.voxengo.com/public/avir/Documentation/a00008_source.html

Initializes the default ditherer with length, variables, and truncation/output parameters.

```cpp
796 Vars = &aVars;
797 LenE = aLen * Vars -> ElCount;
798 TrMul0 = aTrMul;
799 PkOut0 = aPkOut;
800 }
792 void init( const int aLen, const CImageResizerVars& aVars, {…}
```

--------------------------------

### Memory Loading and Storing Methods

Source: https://www.voxengo.com/public/avir/Documentation/a00014_source.html

Static methods for loading data into float8 and instance methods for storing data back to memory, including support for partial limits.

```cpp
 static float8 load( const float* const p )
 {
 return( _mm256_load_ps( p ));
 }

 static float8 loadu( const float* const p )
 {
 return( _mm256_loadu_ps( p ));
 }

 static float8 loadu( const float* const p, const int lim )
 {
 __m128 lo;
 __m128 hi;

 if( lim > 4 )
 {
 lo = _mm_loadu_ps( p );
 hi = loadu4( p + 4, lim - 4 );
 }
 else
 {
 lo = loadu4( p, lim );
 hi = _mm_setzero_ps();
 }

 return( _mm256_insertf128_ps( _mm256_castps128_ps256( lo ), hi, 1 ));
 }

 void store( float* const p ) const
 {
 _mm256_store_ps( p, value );
 }

 void storeu( float* const p ) const
 {
 _mm256_storeu_ps( p, value );
 }

 void storeu( float* p, int lim ) const
 {
 __m128 v;

 if( lim > 4 )
 {
 _mm_storeu_ps( p, _mm256_extractf128_ps( value, 0 ));
 v = _mm256_extractf128_ps( value, 1 );
 p += 4;
 lim -= 4;
 }
 else
 {
 v = _mm256_extractf128_ps( value, 0 );
 }

 if( lim > 2 )
 {
 if( lim > 3 )
 {
 _mm_storeu_ps( p, v );
 }
 else
 {
 _mm_storel_pi( (__m64*) p, v );
 _mm_store_ss( p + 2, _mm_movehl_ps( v, v ));
 }
 }
 else
 {
 if( lim == 2 )
 {
 _mm_storel_pi( (__m64*) p, v );
 }
 else
 {
 _mm_store_ss( p, v );
 }
 }
 }
```

--------------------------------

### CDSPFIREQ::init

Source: https://www.voxengo.com/public/avir/Documentation/a00040.html

Initializes the CDSPFIREQ object with specific filter parameters including sample rate, filter length, and frequency band settings.

```APIDOC
## void init (const double SampleRate, const double aFilterLength, const int aBandCount, const double MinFreq, const double MaxFreq, const bool IsLogBands, const double WFAlpha)

### Description
Initializes the object with the required parameters for FIR filter generation.

### Parameters
- **SampleRate** (double) - The sample rate of the audio.
- **aFilterLength** (double) - The length of the filter.
- **aBandCount** (int) - The number of frequency bands.
- **MinFreq** (double) - The minimum frequency.
- **MaxFreq** (double) - The maximum frequency.
- **IsLogBands** (bool) - Whether to use logarithmic bands.
- **WFAlpha** (double) - The window function alpha parameter.
```

--------------------------------

### CDSPFracFilterBankLin::init

Source: https://www.voxengo.com/public/avir/Documentation/a00052.html

Initializes and builds the filter bank based on the provided parameters.

```APIDOC
## void init(const int ReqFracCount, const int ReqOrder, const double BaseLen, const double Cutoff, const double aWFAlpha, const CFltBuffer &aExtFilter, const int aAlignment=0, const int FltLenAlign=1)

### Description
Initializes (builds) the filter bank based on the supplied parameters.

### Parameters
- **ReqFracCount** (int) - Required - The number of fractional filters.
- **ReqOrder** (int) - Required - The order of the interpolation polynomial.
- **BaseLen** (double) - Required - The base length of the filter.
- **Cutoff** (double) - Required - The cutoff frequency.
- **aWFAlpha** (double) - Required - The window function alpha parameter.
- **aExtFilter** (CFltBuffer) - Required - The external filter buffer.
- **aAlignment** (int) - Optional - Alignment value, defaults to 0.
- **FltLenAlign** (int) - Optional - Filter length alignment, defaults to 1.
```

--------------------------------

### Resize2 Implementation

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Template-based resize function with AVX and custom vector support.

```cpp
2224 template< bool UseSP >
2225 static void resize2( const float* const sp, float* op, const size_t opinc,
2226 const CResizePos* rp, const int kl, const int DstLen )
2227 {
2228 #if LANCIR_ALIGN > 4
2229 const int ci = kl >> 2;
2230 const int cir = kl & 3;
2231 #else // LANCIR_ALIGN > 4
2232 const int ci = kl >> 1;
2233 #endif // LANCIR_ALIGN > 4
2234
2235 LANCIR_LF_PRE
2236
2237 int c = ci;
2238
2239 #if defined( LANCIR_AVX )
2240
2241 __m256 sum = _mm256_mul_ps( _mm256_load_ps( flt ),
2242 _mm256_loadu_ps( ip ));
2243
2244 while( --c != 0 )
2245 {
2246 flt += 8;
2247 ip += 8;
2248 sum = _mm256_add_ps( sum, _mm256_mul_ps( _mm256_load_ps( flt ),
2249 _mm256_loadu_ps( ip )));
2250 }
2251
2252 __m128 res = _mm_add_ps( _mm256_extractf128_ps( sum, 0 ),
2253 _mm256_extractf128_ps( sum, 1 ));
2254
2255 if( cir == 2 )
2256 {
2257 res = _mm_add_ps( res, _mm_mul_ps( _mm_load_ps( flt + 8 ),
2258 _mm_loadu_ps( ip + 8 )));
2259 }
2260
2261 _mm_storel_pi( (__m64*) op,
2262 _mm_add_ps( res, _mm_movehl_ps( res, res )));
2263
2264 #elif LANCIR_ALIGN > 4
2265
2266 lancvec_t sumA = lancvec_mul(
2267 lancvec_load( flt ), lancvec_loadu( ip ));
2268
2269 lancvec_t sumB = lancvec_mul(
2270 lancvec_load( flt + 4 ), lancvec_loadu( ip + 4 ));
2271
2272 while( --c != 0 )
2273 {
2274 flt += 8;
2275 ip += 8;
2276 sumA = lancvec_madd( sumA, lancvec_load( flt ),
2277 lancvec_loadu( ip ));
2278
2279 sumB = lancvec_madd( sumB, lancvec_load( flt + 4 ),
2280 lancvec_loadu( ip + 4 ));
2281 }
2282
2283 sumA = lancvec_add( sumA, sumB );
2284
2285 if( cir == 2 )
2286 {
2287 sumA = lancvec_madd( sumA, lancvec_load( flt + 8 ),
2288 lancvec_loadu( ip + 8 ));
2289 }
2290
2291 lancvec_store64_addhl( op, sumA );
2292
2293 #else // LANCIR_ALIGN > 4
2294
2295 const float xx = flt[ 0 ];
2296 const float xx2 = flt[ 1 ];
2297 float sum0 = xx * ip[ 0 ];
2298 float sum1 = xx * ip[ 1 ];
2299 float sum2 = xx2 * ip[ 2 ];
2300 float sum3 = xx2 * ip[ 3 ];
2301
2302 while( --c != 0 )
2303 {
2304 flt += 2;
2305 ip += 4;
2306 const float xx = flt[ 0 ];
2307 const float xx2 = flt[ 1 ];
2308 sum0 += xx * ip[ 0 ];
2309 sum1 += xx * ip[ 1 ];
2310 sum2 += xx2 * ip[ 2 ];
2311 sum3 += xx2 * ip[ 3 ];
2312 }
2313
2314 op[ 0 ] = sum0 + sum2;
2315 op[ 1 ] = sum1 + sum3;
2316
2317 #endif // LANCIR_ALIGN > 4
2318
2319 LANCIR_LF_POST
2320 }
```

--------------------------------

### void buildFilter(const double *const _BandGains_, double *const _Filter_)

Source: https://www.voxengo.com/public/avir/Documentation/a00040.html

Creates a symmetric-odd FIR filter based on specified gain levels at band crossover points.

```APIDOC
## void buildFilter(const double *const _BandGains_, double *const _Filter_)

### Description
Creates symmetric-odd FIR filter with the specified gain levels at band crossover points.

### Parameters
- **_BandGains_** (const double *const) - Array of linear gain levels, count equals BandCount specified in the init() function.
- **_Filter_** (double *const) - Output filter buffer, length equals getFilterLength().
```

--------------------------------

### doResize Method Implementation

Source: https://www.voxengo.com/public/avir/Documentation/a00008_source.html

Core resizing logic handling different filter orders and element counts using SIMD instructions.

```cpp
void doResize( const fptype* SrcLine, fptype* DstLine,
 int DstLineIncr, fptype* const xx ) const
 {
 const int IntFltLen = FltBank -> getFilterLen();
 const int ElCount = Vars -> ElCount;
 const int elalign = Vars -> elalign;
 const typename CImageResizerFilterStep< fptype, fptype > ::
 CResizePos* rpos = &(*RPosBuf)[ 0 ];

 int DstLineLen = OutLen;
 int i;
 int j;

#define AVIR_RESIZE_PART1 \
 while( DstLineLen > 0 ) \
 { \
 const fptypesimd x = (fptypesimd) rpos -> x; \
 const fptype* ftp = rpos -> ftp; \
 const fptype* ftp2 = rpos -> ftp + IntFltLen; \
 const fptype* Src = SrcLine + rpos -> SrcOffs;

#define AVIR_RESIZE_PART1nx \
 while( DstLineLen > 0 ) \
 { \
 const fptype* ftp = rpos -> ftp; \
 const fptype* Src = SrcLine + rpos -> SrcOffs;

#define AVIR_RESIZE_PART2 \
 DstLine += DstLineIncr; \
 rpos++; \
 DstLineLen--; \
 }

 if( ElCount == 1 )
 {
 if( FltBank -> getOrder() == 1 )
 {
 AVIR_RESIZE_PART1

 fptypesimd sum = ( fptypesimd :: load( ftp ) +
 fptypesimd :: load( ftp2 ) * x ) *
 fptypesimd :: loadu( Src );

 for( i = elalign; i < IntFltLen; i += elalign )
 {
 sum += ( fptypesimd :: load( ftp + i ) +
 fptypesimd :: load( ftp2 + i ) * x ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();

 AVIR_RESIZE_PART2
 }
 else
 {
 AVIR_RESIZE_PART1nx

 fptypesimd sum = fptypesimd :: load( ftp ) *
 fptypesimd :: loadu( Src );

 for( i = elalign; i < IntFltLen; i += elalign )
 {
 sum += fptypesimd :: load( ftp + i ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();

 AVIR_RESIZE_PART2
 }
 }
 else
 if( DstLineIncr == 1 )
 {
 // Horizontal-oriented processing, element loop is outer.

 const int SrcIncr = InElIncr;
 const int DstLineElIncr = OutElIncr - DstLineIncr * DstLineLen;

 if( FltBank -> getOrder() == 1 )
 {
 for( j = 0; j < ElCount; j++ )
 {
 AVIR_RESIZE_PART1

 fptypesimd sum = 0.0;

 for( i = 0; i < IntFltLen; i += elalign )
 {
 sum += ( fptypesimd :: load( ftp + i ) +
 fptypesimd :: load( ftp2 + i ) * x ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();

 AVIR_RESIZE_PART2

 DstLine += DstLineElIncr;
 SrcLine += SrcIncr;
 DstLineLen = OutLen;
 rpos = &(*RPosBuf)[ 0 ];
 }
 }
 else
 {
 for( j = 0; j < ElCount; j++ )
 {
 AVIR_RESIZE_PART1nx

 fptypesimd sum = fptypesimd :: load( ftp ) *
 fptypesimd :: loadu( Src );

 for( i = elalign; i < IntFltLen; i += elalign )
 {
 sum += fptypesimd :: load( ftp + i ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();

 AVIR_RESIZE_PART2

 DstLine += DstLineElIncr;
 SrcLine += SrcIncr;
 DstLineLen = OutLen;
 rpos = &(*RPosBuf)[ 0 ];
 }
 }
 }
 else
 {
 const int SrcIncr = InElIncr;
 const int DstLineElIncr = OutElIncr;
 DstLineIncr -= DstLineElIncr * ElCount;

 if( FltBank -> getOrder() == 1 )
 {
 AVIR_RESIZE_PART1

 for( i = 0; i < IntFltLen; i += elalign )
 {
 ( fptypesimd :: load( ftp + i ) +
 fptypesimd :: load( ftp2 + i ) * x ).store( xx + i );
 }

 for( j = 0; j < ElCount; j++ )
 {
 fptypesimd sum = fptypesimd :: load( xx ) *
 fptypesimd :: loadu( Src );

 for( i = elalign; i < IntFltLen; i += elalign )
 {
 sum += fptypesimd :: load( xx + i ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();
 DstLine += DstLineElIncr;
 Src += SrcIncr;
 }

 AVIR_RESIZE_PART2
 }
 else
 {
 AVIR_RESIZE_PART1nx

 for( j = 0; j < ElCount; j++ )
 {
 fptypesimd sum = fptypesimd :: load( ftp ) *
 fptypesimd :: loadu( Src );

 for( i = elalign; i < IntFltLen; i += elalign )
 {
 sum += fptypesimd :: load( ftp + i ) *
 fptypesimd :: loadu( Src + i );
 }

 DstLine[ 0 ] = sum.hadd();
 DstLine += DstLineElIncr;
 Src += SrcIncr;
 }

 AVIR_RESIZE_PART2
 }
 }

#undef AVIR_RESIZE_PART2
#undef AVIR_RESIZE_PART1nx
#undef AVIR_RESIZE_PART1
 }
```

--------------------------------

### Resize3 Implementation

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Template-based resize function with AVX optimization for larger vector operations.

```cpp
2322 template< bool UseSP >
2323 static void resize3( const float* const sp, float* op, const size_t opinc,
2324 const CResizePos* rp, const int kl, const int DstLen )
2325 {
2326 #if LANCIR_ALIGN > 4
2327
2328 const int ci = kl >> 2;
2329 const int cir = kl & 3;
2330
2331 LANCIR_LF_PRE
2332
2333 float res[ 12 ];
2334 int c = ci;
2335
2336 #if defined( LANCIR_AVX )
2337
2338 __m128 sumA = _mm_mul_ps( _mm_load_ps( flt ), _mm_loadu_ps( ip ));
2339 __m256 sumB = _mm256_mul_ps( _mm256_loadu_ps( flt + 4 ),
2340 _mm256_loadu_ps( ip + 4 ));
2341
2342 while( --c != 0 )
2343 {
2344 flt += 12;
2345 ip += 12;
2346 sumA = _mm_add_ps( sumA, _mm_mul_ps( _mm_load_ps( flt ),
2347 _mm_loadu_ps( ip )));
2348
2349 sumB = _mm256_add_ps( sumB, _mm256_mul_ps(
2350 _mm256_loadu_ps( flt + 4 ), _mm256_loadu_ps( ip + 4 )));
2351 }
2352
2353 if( cir == 2 )
```

--------------------------------

### Private Helper Methods

Source: https://www.voxengo.com/public/avir/Documentation/a00014_source.html

Internal helper methods for handling partial vector loads.

```cpp
 static __m128 loadu4( const float* const p, const int lim )
 {
 if( lim > 2 )
 {
 if( lim > 3 )
 {
 return( _mm_loadu_ps( p ));
 }
 else
 {
 return( _mm_set_ps( 0.0f, p[ 2 ], p[ 1 ], p[ 0 ]));
 }
 }
 else
 {
 if( lim == 2 )
 {

```

--------------------------------

### CDSPPeakedCosineLPF Constructor

Source: https://www.voxengo.com/public/avir/Documentation/a00044.html

Initializes the CDSPPeakedCosineLPF object with specified filter parameters.

```APIDOC
## CDSPPeakedCosineLPF(const double aLen2, const double aFreq2, const double aAlpha)

### Description
Initializes the object with the specified filter length, corner frequency, and window alpha parameter.

### Parameters
- **aLen2** (double) - Half-length (non-truncated) of low-pass filter, in samples (taps).
- **aFreq2** (double) - Low-pass filter's corner frequency, [0; pi].
- **aAlpha** (double) - Peaked Cosine window function Alpha parameter.
```

--------------------------------

### Include Required Headers

Source: https://www.voxengo.com/public/avir/Documentation/a00017.html

Standard library headers required for the LANCIR implementation.

```cpp
#include <cstring>
#include <cmath>
#include <stdint.h>
```

--------------------------------

### static void addu(float *const p, const float8 &v)

Source: https://www.voxengo.com/public/avir/Documentation/a00164.html

Performs in-place addition of a value located in memory and the specified float8 value.

```APIDOC
## static void addu(float *const p, const float8 &v)

### Description
Performs in-place addition of a value located in memory, and the specified value.

### Parameters
- **p** (float *const) - Pointer to value where addition happens. May be unaligned.
- **v** (const float8 &) - Value to add.
```

--------------------------------

### prepareInBuf()

Source: https://www.voxengo.com/public/avir/Documentation/a00144.html

Prepares the input scanline buffer for the filtering step by replicating edge pixels to prevent buffer overruns.

```APIDOC
## void prepareInBuf(fptype *Src)

### Description
Prepares input scanline buffer for this filtering step. Left- and right-most pixels are replicated to make sure no buffer overrun happens, allowing the bypass of pointer range checks.

### Parameters
- **Src** (fptype*) - Required - Source buffer.
```

--------------------------------

### int calcInitComplexity(const CBuffer<char> &FracUseMap)

Source: https://www.voxengo.com/public/avir/Documentation/a00052.html

Calculates the approximate initialization complexity in terms of multiply-add operations for the fractional delay filter bank.

```APIDOC
## int calcInitComplexity(const CBuffer<char> &FracUseMap)

### Description
Returns an approximate initialization complexity, expressed in the number of multiply-add operations. This includes fractional delay filters calculation and multiplication by an external filter. This function can only be called after the init() function.

### Parameters
#### Parameters
- **FracUseMap** (const CBuffer<char> &) - Required - Fractional delays use map, each element corresponds to a single fractional delay, will be compared to the internal table fill flags. This map should include 0 and 1 values only.

### Returns
- **int** - The complexity of the initialization, expressed in the number of multiply-add operations.
```

--------------------------------

### alloc()

Source: https://www.voxengo.com/public/avir/Documentation/a00024.html

Allocates memory to store a specified number of elements in the buffer.

```APIDOC
## void alloc(const capint _aCapacity_, const int _aAlignment_ = 0)

### Description
Allocates memory so that the specified number of elements can be stored in this buffer object.

### Parameters
- **_aCapacity_** (capint) - Required - Storage for this number of elements to allocate.
- **_aAlignment_** (int) - Optional - Buffer's required memory address alignment, power-of-2 values only. 0 - use stdlib's default alignment.
```

--------------------------------

### CImageResizerParamsUltra Configuration Parameters

Source: https://www.voxengo.com/public/avir/Documentation/a00088.html

This class defines the configuration parameters used for ultra low-aliasing image resizing. These parameters control the behavior of the interpolation, low-pass, and correction filters.

```APIDOC
## CImageResizerParamsUltra

### Description
A set of resizing algorithm parameters for ultra low-aliasing resizing. This configuration provides high anti-aliasing performance and frequency response linearity, though it is computationally expensive and may introduce ringing artifacts on sharp features.

### Parameters
- **CorrFltAlpha** (double) - Alpha parameter of the Peaked Cosine window function for the correction filter (Usable range: 1.0 to 1.5).
- **CorrFltLen** (double) - Correction filter length in samples (Usable range: 5.5 to 8).
- **HBFltAlpha** (double) - Half-band filter Alpha (Assigned internally).
- **HBFltCutoff** (double) - Half-band filter cutoff point [0; 1] (Assigned internally).
- **HBFltLen** (double) - Length of the half-band low-pass filter (Assigned internally).
- **IntFltAlpha** (double) - Alpha parameter of the Peaked Cosine window function for the interpolation low-pass filter (Usable range: 1.5 to 2.5).
- **IntFltCutoff** (double) - Interpolation low-pass filter cutoff frequency [0; 1] (Usable range: 0.6 to 0.8).
- **IntFltLen** (double) - Interpolation low-pass filter length in samples (Should be at least 18).
- **LPFltAlpha** (double) - Alpha parameter of the Peaked Cosine window function for the low-pass filter (Usable range: 1.5 to 6.5).
- **LPFltBaseLen** (double) - Base length of the low-pass filter in samples (Usable range: 6 to 9).
- **LPFltCutoffMult** (double) - Low-pass filter cutoff frequency multiplier (Usable range: 0.3 to 1.0).
```

--------------------------------

### getRPosBuf

Source: https://www.voxengo.com/public/avir/Documentation/a00112.html

Retrieves a resizing positions buffer with the specified stepping, creating it if it does not already exist.

```APIDOC
## CRPosBuf & getRPosBuf(const double k, const double o, const int FracCount)

### Description
Returns the resizing positions buffer with the required stepping. If no such buffer exists, it is created.

### Parameters
- **k** (double) - Resizing step.
- **o** (double) - Resizing offset.
- **FracCount** (int) - The number of fractional delay filters in a filter bank used together with this buffer.

### Returns
- **CRPosBuf &** - Reference to the CRPosBuf object.
```

--------------------------------

### Error-Diffusion Ditherer Initialization

Source: https://www.voxengo.com/public/avir/Documentation/a00008_source.html

Initializes the error-diffusion ditherer and allocates memory for the scanline buffer.

```cpp
895 void init( const int aLen, const CImageResizerVars& aVars,
896 const double aTrMul, const double aPkOut )
897 {
898 Len = aLen;
899 Vars = &aVars;
900 LenE = aLen * Vars -> ElCount;
901 TrMul0 = aTrMul;
902 PkOut0 = aPkOut;
903
904 ResScanlineDith0.alloc( LenE + Vars -> ElCount, sizeof( fptype ));
905 ResScanlineDith = ResScanlineDith0 + Vars -> ElCount;
906 int i;
907
908 for( i = 0; i < LenE + Vars -> ElCount; i++ )
909 {
910 ResScanlineDith0[ i ] = 0.0;
911 }
912 }
895 void init( const int aLen, const CImageResizerVars& aVars, {…}
```

--------------------------------

### copyInitParams()

Source: https://www.voxengo.com/public/avir/Documentation/a00052.html

Copies a limited set of parameters from a source filter bank. Note that actual filters are not copied and a subsequent init() call is required.

```APIDOC
## void copyInitParams(const CDSPFracFilterBankLin<fptype> &s)

### Description
Copies a limited set of parameters of the source filter bank. The actual filters are not copied. Such copying is used during filtering steps "modeling" stage. A further init() function call is required.

### Parameters
- **s** (const CDSPFracFilterBankLin<fptype> &) - Required - Source filter bank.
```

--------------------------------

### Resize Kernel Implementation

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Template-based resize function using either SIMD vectors or scalar accumulation.

```cpp
template< bool UseSP >
static void resize1( const float* const sp, float* op, const size_t opinc,
const CResizePos* rp, const int kl, const int DstLen )
{
const int ci = kl >> 2;

if(( kl & 3 ) == 0 )
{
LANCIR_LF_PRE

int c = ci;

#if LANCIR_ALIGN > 4

lancvec_t sum = lancvec_mul(
lancvec_load( flt ), lancvec_loadu( ip ));

while( --c != 0 )
{
flt += 4;
ip += 4;
sum = lancvec_madd( sum, lancvec_load( flt ),
lancvec_loadu( ip ));
}

lancvec_store32_hadd( op, sum );

#else // LANCIR_ALIGN > 4

float sum0 = flt[ 0 ] * ip[ 0 ];
float sum1 = flt[ 1 ] * ip[ 1 ];
float sum2 = flt[ 2 ] * ip[ 2 ];
float sum3 = flt[ 3 ] * ip[ 3 ];

while( --c != 0 )
{
flt += 4;
ip += 4;
sum0 += flt[ 0 ] * ip[ 0 ];
sum1 += flt[ 1 ] * ip[ 1 ];
sum2 += flt[ 2 ] * ip[ 2 ];
sum3 += flt[ 3 ] * ip[ 3 ];
}

op[ 0 ] = ( sum0 + sum1 ) + ( sum2 + sum3 );

#endif // LANCIR_ALIGN > 4
```

--------------------------------

### prepareInBuf

Source: https://www.voxengo.com/public/avir/Documentation/a00144.html

Prepares input scanline buffer for this filtering step.

```APIDOC
## void prepareInBuf(fptype *Src) const

### Description
Prepares input scanline buffer for this filtering step.

### Parameters
- **Src** (fptype *) - Source buffer
```

--------------------------------

### Buffer Reallocation Utilities

Source: https://www.voxengo.com/public/avir/Documentation/a00017_source.html

Static template functions for managing memory buffers with alignment support.

```cpp
template< typename Tb, typename Tl >
static void reallocBuf( Tb*& buf0, Tb*& buf, Tl& len, Tl newlen )
{
	newlen += LANCIR_ALIGN;

	if( newlen > len )
	{
		if( buf0 != nullptr )
		{
			delete[] buf0;
			buf0 = nullptr;
			len = 0;
		}

		buf0 = new Tb[ newlen ];
		len = newlen;
		buf = (Tb*) (( (uintptr_t) buf0 + LANCIR_ALIGN - 1 ) &
			~(uintptr_t) ( LANCIR_ALIGN - 1 ));
	}
}
```

```cpp
template< typename Tb, typename Tl >
static void reallocBuf( Tb*& buf, Tl& len, const Tl newlen )
{
	if( newlen > len )
	{
		if( buf != nullptr )
		{
			delete[] buf;
			buf = nullptr;
			len = 0;
		}

		buf = new Tb[ newlen ];
		len = newlen;
	}
}
```

--------------------------------

### Define LANCIR Macros

Source: https://www.voxengo.com/public/avir/Documentation/a00017.html

Configuration macros for address alignment and compatibility.

```cpp
#define LANCIR_ALIGN 4
```

```cpp
#define LANCIR_NULLPTR
```

```cpp
#define nullptr NULL
```

--------------------------------

### CImageResizer Constructor

Source: https://www.voxengo.com/public/avir/Documentation/a00129.html

Initializes a new instance of the CImageResizer class with specified bit depths and parameters.

```APIDOC
## CImageResizer(const int aResBitDepth, const int aSrcBitDepth, const CImageResizerParams &aParams)

### Description
Constructs the image resizer object with defined bit depth settings and resizing parameters.

### Parameters
- **aResBitDepth** (int) - Optional - The bit depth of the result image (default: 8).
- **aSrcBitDepth** (int) - Optional - The bit depth of the source image (default: 0).
- **aParams** (CImageResizerParams) - Optional - The resizing parameters to use (default: CImageResizerParamsDef()).
```

--------------------------------

### void doResize(const fptype *SrcLine, fptype *DstLine, const int DstLineIncr, fptype * const _)

Source: https://www.voxengo.com/public/avir/Documentation/a00116.html

Performs resizing of a single scanline. Requires the source buffer to be padded to prevent out-of-bounds access.

```APIDOC
## void doResize(const fptype *SrcLine, fptype *DstLine, const int DstLineIncr, fptype * const _)

### Description
Performs resizing of a single scanline. This function does not "know" about the length of the source scanline buffer. This buffer should be padded with enough pixels so that SrcPos - FilterLenD2 is always greater or equal to 0, and SrcPos + ( DstLineLen - 1 ) * k + FilterLenD2 + 1 does not exceed source scanline's buffer length. SrcLine increment is assumed to be equal to ElCount.

### Parameters
- **SrcLine** (const fptype *) - Source scanline buffer.
- **DstLine** (fptype *) - Destination (resized) scanline buffer.
- **DstLineIncr** (const int) - Destination scanline position increment, used for horizontal or vertical scanline stepping.
- **_** (fptype * const) - Additional parameter.
```

--------------------------------

### static void addu(float *const p, const float8 &v, const int lim)

Source: https://www.voxengo.com/public/avir/Documentation/a00164.html

Performs in-place addition of a value located in memory and the specified float8 value, limited to the specified number of elements.

```APIDOC
## static void addu(float *const p, const float8 &v, const int lim)

### Description
Performs in-place addition of a value located in memory, and the specified value. Limited to the specified number of elements.
```