gx_resampler.h

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/*
 * Copyright (C) 2009, 2010 Hermann Meyer, James Warden, Andreas Degert
 * Copyright (C) 2011 Pete Shorthose
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 * --------------------------------------------------------------------------
 */
 
/* ------- This is the guitarix resampler, to use zita-resampler ------- */
 
#pragma once
 
#ifndef SRC_HEADERS_GX_RESAMPLER_H_
#define SRC_HEADERS_GX_RESAMPLER_H_
 
#include <zita-resampler/resampler.h>
 
namespace gx_resample {
 
#define MAX_UPSAMPLE 8
 
class SimpleResampler {
 private:
    Resampler r_up, r_down;
    int m_fact;
 public:
    SimpleResampler(): r_up(), r_down(), m_fact() {}
    void setup(int sampleRate, unsigned int fact);
    void up(int count, float *input, float *output);
    void down(int count, float *input, float *output);
};
 
class BufferResampler: Resampler {
 public:
    float *process(int fs_inp, int ilen, float *input, int fs_outp, int* olen);
};
 
class StreamingResampler: Resampler {
 private:
    int ratio_a;
    int ratio_b;
 public:
    bool setup(int srcRate, int dstRate, int nchan);
    int get_max_out_size(int i_size) { return (i_size * ratio_b) / ratio_a + 1; }
    int process(int count, float *input, float *output);
    int flush(float *output); // check source for max. output size
};
 
class FixedRateResampler {
private:
    Resampler r_up, r_down;
    int inputRate, outputRate;
public:
    int setup(int _inputRate, int _outputRate);
    int up(int count, float *input, float *output);
    void down(float *input, float *output);
    int max_out_count(int in_count) {
    if (inputRate > outputRate) return in_count;
    return static_cast<int>(ceil((in_count*static_cast<double>(outputRate))/inputRate)); }
};
 
}
#endif  // SRC_HEADERS_GX_RESAMPLER_H_