PaulStretch Class Reference

Class that helps EffectPaulStretch. It does the FFTs and inner loop of the effect. More...

Collaboration diagram for PaulStretch:

Public Member Functions
	PaulStretch (float rap_, size_t in_bufsize_, float samplerate_)
virtual	~PaulStretch ()
void	process (float *smps, size_t nsmps)
size_t	get_nsamples ()
size_t	get_nsamples_for_fill ()

Public Attributes
const size_t	out_bufsize
const Floats	out_buf
const size_t	poolsize

Private Member Functions
void	process_spectrum (float *WXUNUSED(freq))

Private Attributes
const float	samplerate
const float	rap
const size_t	in_bufsize
const Floats	old_out_smp_buf
const Floats	in_pool
double	remained_samples
const Floats	fft_smps
const Floats	fft_c
const Floats	fft_s
const Floats	fft_freq
const Floats	fft_tmp

Detailed Description

Class that helps EffectPaulStretch. It does the FFTs and inner loop of the effect.

Definition at line 47 of file Paulstretch.cpp.

Constructor & Destructor Documentation

PaulStretch()

PaulStretch::PaulStretch	(	float	rap_,
		size_t	in_bufsize_,
		float	samplerate_
	)

Definition at line 421 of file Paulstretch.cpp.

   : samplerate { samplerate_ }
   , rap { std::max(1.0f, rap_) }
   , in_bufsize { in_bufsize_ }
   , out_bufsize { std::max(size_t{ 8 }, in_bufsize) }
   , out_buf { out_bufsize }
   , old_out_smp_buf { out_bufsize * 2, true }
   , poolsize { in_bufsize_ * 2 }
   , in_pool { poolsize, true }
   , remained_samples { 0.0 }
   , fft_smps { poolsize, true }
   , fft_c { poolsize, true }
   , fft_s { poolsize, true }
   , fft_freq { poolsize, true }
   , fft_tmp { poolsize }
{
}

~PaulStretch()

PaulStretch::~PaulStretch ( )

virtual

Definition at line 439 of file Paulstretch.cpp.

{
}

Member Function Documentation

get_nsamples()

size_t PaulStretch::get_nsamples

(

)

Definition at line 520 of file Paulstretch.cpp.

{
   double r = out_bufsize / rap;
   auto ri = (size_t)floor(r);
   double rf = r - floor(r);
 
   remained_samples += rf;
   if (remained_samples >= 1.0){
      ri += (size_t)floor(remained_samples);
      remained_samples = remained_samples - floor(remained_samples);
   }
 
   if (ri > poolsize) {
      ri = poolsize;
   }
 
   return ri;
}

References out_bufsize, poolsize, rap, and remained_samples.

Referenced by EffectPaulstretch::ProcessOne().

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get_nsamples_for_fill()

size_t PaulStretch::get_nsamples_for_fill

(

)

Definition at line 539 of file Paulstretch.cpp.

{
   return poolsize;
}

References poolsize.

Referenced by EffectPaulstretch::ProcessOne().

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process()

void PaulStretch::process	(	float *	smps,
		size_t	nsmps
	)

Definition at line 443 of file Paulstretch.cpp.

{
   //add NEW samples to the pool
   if ((smps != NULL) && (nsmps != 0)) {
      if (nsmps > poolsize) {
         nsmps = poolsize;
      }
      int nleft = poolsize - nsmps;
 
      //move left the samples from the pool to make room for NEW samples
      for (int i = 0; i < nleft; i++)
         in_pool[i] = in_pool[i + nsmps];
 
      //add NEW samples to the pool
      for (size_t i = 0; i < nsmps; i++)
         in_pool[i + nleft] = smps[i];
   }
 
   //get the samples from the pool
   for (size_t i = 0; i < poolsize; i++)
      fft_smps[i] = in_pool[i];
   WindowFunc(eWinFuncHann, poolsize, fft_smps.get());
 
   RealFFT(poolsize, fft_smps.get(), fft_c.get(), fft_s.get());
 
   for (size_t i = 0; i < poolsize / 2; i++)
      fft_freq[i] = sqrt(fft_c[i] * fft_c[i] + fft_s[i] * fft_s[i]);
   process_spectrum(fft_freq.get());
 
 
   //put randomize phases to frequencies and do a IFFT
   float inv_2p15_2pi = 1.0 / 16384.0 * (float)M_PI;
   for (size_t i = 1; i < poolsize / 2; i++) {
      unsigned int random = (rand()) & 0x7fff;
      float phase = random * inv_2p15_2pi;
      float s = fft_freq[i] * sin(phase);
      float c = fft_freq[i] * cos(phase);
 
      fft_c[i] = fft_c[poolsize - i] = c;
 
      fft_s[i] = s; fft_s[poolsize - i] = -s;
   }
   fft_c[0] = fft_s[0] = 0.0;
   fft_c[poolsize / 2] = fft_s[poolsize / 2] = 0.0;
 
   FFT(poolsize, true, fft_c.get(), fft_s.get(), fft_smps.get(), fft_tmp.get());
 
   float max = 0.0, max2 = 0.0;
   for (size_t i = 0; i < poolsize; i++) {
      max = std::max(max, fabsf(fft_tmp[i]));
      max2 = std::max(max2, fabsf(fft_smps[i]));
   }
 
 
   //make the output buffer
   float tmp = 1.0 / (float) out_bufsize * M_PI;
   float hinv_sqrt2 = 0.853553390593f;//(1.0+1.0/sqrt(2))*0.5;
 
   float ampfactor = 1.0;
   if (rap < 1.0)
      ampfactor = rap * 0.707;
   else
      ampfactor = (out_bufsize / (float)poolsize) * 4.0;
 
   for (size_t i = 0; i < out_bufsize; i++) {
      float a = (0.5 + 0.5 * cos(i * tmp));
      float out = fft_smps[i + out_bufsize] * (1.0 - a) + old_out_smp_buf[i] * a;
      out_buf[i] =
         out * (hinv_sqrt2 - (1.0 - hinv_sqrt2) * cos(i * 2.0 * tmp)) *
         ampfactor;
   }
 
   //copy the current output buffer to old buffer
   for (size_t i = 0; i < out_bufsize * 2; i++)
      old_out_smp_buf[i] = fft_smps[i];
}

References eWinFuncHann, FFT(), fft_c, fft_freq, fft_s, fft_smps, fft_tmp, in_pool, M_PI, old_out_smp_buf, out_buf, out_bufsize, poolsize, process_spectrum(), rap, RealFFT(), staffpad::audio::simd::sqrt(), and WindowFunc().

Referenced by EffectPaulstretch::ProcessOne().

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process_spectrum()

void PaulStretch::process_spectrum ( float *  WXUNUSEDfreq )

inlineprivate

Definition at line 60 of file Paulstretch.cpp.

{};

Referenced by process().

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Member Data Documentation

fft_c

const Floats PaulStretch::fft_c

private

Definition at line 81 of file Paulstretch.cpp.

Referenced by process().

fft_freq

const Floats PaulStretch::fft_freq

private

Definition at line 81 of file Paulstretch.cpp.

Referenced by process().

fft_s

const Floats PaulStretch::fft_s

private

Definition at line 81 of file Paulstretch.cpp.

Referenced by process().

fft_smps

const Floats PaulStretch::fft_smps

private

Definition at line 81 of file Paulstretch.cpp.

Referenced by process().

fft_tmp

const Floats PaulStretch::fft_tmp

private

Definition at line 81 of file Paulstretch.cpp.

Referenced by process().

in_bufsize

const size_t PaulStretch::in_bufsize

private

Definition at line 64 of file Paulstretch.cpp.

in_pool

const Floats PaulStretch::in_pool

private

Definition at line 77 of file Paulstretch.cpp.

Referenced by process().

old_out_smp_buf

const Floats PaulStretch::old_out_smp_buf

private

Definition at line 71 of file Paulstretch.cpp.

Referenced by process().

out_buf

const Floats PaulStretch::out_buf

Definition at line 68 of file Paulstretch.cpp.

Referenced by process(), and EffectPaulstretch::ProcessOne().

out_bufsize

const size_t PaulStretch::out_bufsize

Definition at line 67 of file Paulstretch.cpp.

Referenced by get_nsamples(), process(), and EffectPaulstretch::ProcessOne().

poolsize

const size_t PaulStretch::poolsize

Definition at line 74 of file Paulstretch.cpp.

Referenced by get_nsamples(), get_nsamples_for_fill(), process(), and EffectPaulstretch::ProcessOne().

rap

const float PaulStretch::rap

private

Definition at line 63 of file Paulstretch.cpp.

Referenced by get_nsamples(), and process().

remained_samples

double PaulStretch::remained_samples

private

Definition at line 79 of file Paulstretch.cpp.

Referenced by get_nsamples().

samplerate

const float PaulStretch::samplerate

private

Definition at line 62 of file Paulstretch.cpp.

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The documentation for this class was generated from the following file:

• Paulstretch.cpp