Initial git commit

Source/WDL/resample.h

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+/*
+    WDL - resample.h
+    Copyright (C) 2010 and later Cockos Incorporated
+
+    This software is provided 'as-is', without any express or implied
+    warranty.  In no event will the authors be held liable for any damages
+    arising from the use of this software.
+
+    Permission is granted to anyone to use this software for any purpose,
+    including commercial applications, and to alter it and redistribute it
+    freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+       claim that you wrote the original software. If you use this software
+       in a product, an acknowledgment in the product documentation would be
+       appreciated but is not required.
+    2. Altered source versions must be plainly marked as such, and must not be
+       misrepresented as being the original software.
+    3. This notice may not be removed or altered from any source distribution.
+      
+    You may also distribute this software under the LGPL v2 or later.
+
+*/
+
+#ifndef _WDL_RESAMPLE_H_
+#define _WDL_RESAMPLE_H_
+
+#include <stdlib.h>
+#include <string.h>
+#include "wdltypes.h"
+#include "heapbuf.h"
+
+// default to floats for sinc filter ceofficients
+#ifdef WDL_RESAMPLE_FULL_SINC_PRECISION
+typedef double WDL_SincFilterSample; 
+#else
+typedef float WDL_SincFilterSample;
+#endif
+
+// default to doubles for audio samples
+#ifdef WDL_RESAMPLE_TYPE
+typedef WDL_RESAMPLE_TYPE WDL_ResampleSample;
+#else
+typedef double WDL_ResampleSample;
+#endif
+
+
+#ifndef WDL_RESAMPLE_MAX_FILTERS
+#define WDL_RESAMPLE_MAX_FILTERS 4
+#endif
+
+#ifndef WDL_RESAMPLE_MAX_NCH
+#define WDL_RESAMPLE_MAX_NCH 64
+#endif
+
+
+class WDL_Resampler
+{
+public:
+  WDL_Resampler();
+  ~WDL_Resampler();
+  // if sinc set, it overrides interp or filtercnt
+  void SetMode(bool interp, int filtercnt, bool sinc, int sinc_size=64, int sinc_interpsize=32);
+
+  void SetFilterParms(float filterpos=0.693, float filterq=0.707) { m_filterpos=filterpos; m_filterq=filterq; } // used for filtercnt>0 but not sinc
+  void SetFeedMode(bool wantInputDriven) { m_feedmode=wantInputDriven; } // if true, that means the first parameter to ResamplePrepare will specify however much input you have, not how much you want
+
+  void Reset(double fracpos=0.0);
+  void SetRates(double rate_in, double rate_out);
+
+  double GetCurrentLatency(); // amount of input that has been received but not yet converted to output, in seconds
+
+  // req_samples is output samples desired if !wantInputDriven, or if wantInputDriven is input samples that we have
+  // returns number of samples desired (put these into *inbuffer)
+  // note that it is safe to call ResamplePrepare without calling ResampleOut (the next call of ResamplePrepare will function as normal)
+  int ResamplePrepare(int req_samples, int nch, WDL_ResampleSample **inbuffer); 
+  
+
+  // if numsamples_in < the value return by ResamplePrepare(), then it will be flushed to produce all remaining valid samples
+  // do NOT call with nsamples_in greater than the value returned from resamplerprpare()! the extra samples will be ignored.
+  // returns number of samples successfully outputted to out
+  int ResampleOut(WDL_ResampleSample *out, int nsamples_in, int nsamples_out, int nch);
+
+
+
+private:
+  void BuildLowPass(double filtpos);
+  void inline SincSample(WDL_ResampleSample *outptr, const WDL_ResampleSample *inptr, double fracpos, int nch, const WDL_SincFilterSample *filter, int filtsz);
+  void inline SincSample1(WDL_ResampleSample *outptr, const WDL_ResampleSample *inptr, double fracpos, const WDL_SincFilterSample *filter, int filtsz);
+  void inline SincSample2(WDL_ResampleSample *outptr, const WDL_ResampleSample *inptr, double fracpos, const WDL_SincFilterSample *filter, int filtsz);
+
+  double m_sratein WDL_FIXALIGN;
+  double m_srateout;
+  double m_fracpos;
+  double m_ratio;
+  double m_filter_ratio;
+  float m_filterq, m_filterpos;
+  WDL_TypedBuf<WDL_ResampleSample> m_rsinbuf;
+  WDL_TypedBuf<WDL_SincFilterSample> m_filter_coeffs;
+
+  class WDL_Resampler_IIRFilter;
+  WDL_Resampler_IIRFilter *m_iirfilter;
+
+  int m_filter_coeffs_size;
+  int m_last_requested;
+  int m_filtlatency;
+  int m_samples_in_rsinbuf;
+  int m_lp_oversize;
+
+  int m_sincsize;
+  int m_filtercnt;
+  int m_sincoversize;
+  bool m_interp;
+  bool m_feedmode;
+
+};
+
+
+
+#endif