common/JackResampler.h

   1 /*
   2 Copyright (C) 2008 Grame
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation; either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #ifndef __JackResampler__
  21 #define __JackResampler__
  22
  23 #include "ringbuffer.h"
  24 #include "JackError.h"
  25
  26 namespace Jack
  27 {
  28
  29 #define DEFAULT_RB_SIZE 32768
  30 #define DEFAULT_ADAPTATIVE_SIZE 2048
  31
  32 inline float Range(float min, float max, float val)
  33 {
  34     return (val < min) ? min : ((val > max) ? max : val);
  35 }
  36
  37 /*!
  38 \brief Base class for Resampler.
  39 */
  40
  41 class JackResampler
  42 {
  43
  44     protected:
  45
  46         jack_ringbuffer_t* fRingBuffer;
  47         double fRatio;
  48         unsigned int fRingBufferSize;
  49
  50     public:
  51
  52         JackResampler();
  53         virtual ~JackResampler();
  54
  55         virtual void Reset(unsigned int new_size);
  56
  57         virtual unsigned int ReadResample(float* buffer, unsigned int frames);
  58         virtual unsigned int WriteResample(float* buffer, unsigned int frames);
  59
  60         virtual unsigned int Read(float* buffer, unsigned int frames);
  61         virtual unsigned int Write(float* buffer, unsigned int frames);
  62
  63         virtual unsigned int ReadSpace();
  64         virtual unsigned int WriteSpace();
  65
  66         unsigned int GetError()
  67         {
  68             return (jack_ringbuffer_read_space(fRingBuffer) / sizeof(float)) - (fRingBufferSize / 2);
  69         }
  70
  71         void SetRatio(double ratio)
  72         {
  73             fRatio = Range(0.25, 4.0, ratio);
  74         }
  75
  76         double GetRatio()
  77         {
  78             return fRatio;
  79         }
  80
  81     };
  82 }
  83
  84 #endif