view base/Resampler.cpp @ 631:3a5ee4b6c9ad

* Complete the overhaul of CSV file import; now you can pick the purpose for
  each column in the file, and SV should do the rest.  The most significant
  practical improvement here is that we can now handle files in which time
  and duration do not necessarily appear in known columns.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

/*
   This is a modified version of a source file from the 
   Rubber Band audio timestretcher library.
   This file copyright 2007 Chris Cannam.
*/

#include "Resampler.h"

#include <cstdlib>
#include <cmath>

#include <iostream>

#include <samplerate.h>

class Resampler::D
{
public:
    D(Quality quality, size_t channels, size_t chunkSize);
    ~D();

    size_t resample(float **in, float **out,
                    size_t incount, float ratio,
                    bool final);

    size_t resampleInterleaved(float *in, float *out,
                               size_t incount, float ratio,
                               bool final);

    void reset();

protected:
    SRC_STATE *m_src;
    float *m_iin;
    float *m_iout;
    size_t m_channels;
    size_t m_iinsize;
    size_t m_ioutsize;
};

Resampler::D::D(Quality quality, size_t channels, size_t chunkSize) :
    m_src(0),
    m_iin(0),
    m_iout(0),
    m_channels(channels),
    m_iinsize(0),
    m_ioutsize(0)
{
    int err = 0;
    m_src = src_new(quality == Best ? SRC_SINC_BEST_QUALITY :
                    quality == Fastest ? SRC_LINEAR :
                    SRC_SINC_FASTEST,
                    channels, &err);

    //!!! check err, throw

    if (chunkSize > 0 && m_channels > 1) {
        //!!! alignment?
        m_iinsize = chunkSize * m_channels;
        m_ioutsize = chunkSize * m_channels * 2;
        m_iin = (float *)malloc(m_iinsize * sizeof(float));
        m_iout = (float *)malloc(m_ioutsize * sizeof(float));
    }
}

Resampler::D::~D()
{
    src_delete(m_src);
    if (m_iinsize > 0) {
        free(m_iin);
    }
    if (m_ioutsize > 0) {
        free(m_iout);
    }
}

size_t
Resampler::D::resample(float **in, float **out,
                       size_t incount, float ratio,
                       bool final)
{
    if (m_channels == 1) {
        return resampleInterleaved(*in, *out, incount, ratio, final);
    }

    size_t outcount = lrintf(ceilf(incount * ratio));

    if (incount * m_channels > m_iinsize) {
        m_iinsize = incount * m_channels;
        m_iin = (float *)realloc(m_iin, m_iinsize * sizeof(float));
    }
    if (outcount * m_channels > m_ioutsize) {
        m_ioutsize = outcount * m_channels;
        m_iout = (float *)realloc(m_iout, m_ioutsize * sizeof(float));
    }
    for (size_t i = 0; i < incount; ++i) {
        for (size_t c = 0; c < m_channels; ++c) {
            m_iin[i * m_channels + c] = in[c][i];
        }
    }
    
    size_t gen = resampleInterleaved(m_iin, m_iout, incount, ratio, final);

    for (size_t i = 0; i < gen; ++i) {
        for (size_t c = 0; c < m_channels; ++c) {
            out[c][i] = m_iout[i * m_channels + c];
        }
    }

    return gen;
}

size_t
Resampler::D::resampleInterleaved(float *in, float *out,
                                  size_t incount, float ratio,
                                  bool final)
{
    SRC_DATA data;

    size_t outcount = lrintf(ceilf(incount * ratio));

    data.data_in = in;
    data.data_out = out;
    data.input_frames = incount;
    data.output_frames = outcount;
    data.src_ratio = ratio;
    data.end_of_input = (final ? 1 : 0);

    int err = src_process(m_src, &data);

    //!!! check err, respond appropriately

    return data.output_frames_gen;
}

void
Resampler::D::reset()
{
    src_reset(m_src);
}

Resampler::Resampler(Quality quality, size_t channels, size_t chunkSize)
{
    m_d = new D(quality, channels, chunkSize);
}

Resampler::~Resampler()
{
    delete m_d;
}

size_t 
Resampler::resample(float **in, float **out,
                    size_t incount, float ratio,
                    bool final)
{
    return m_d->resample(in, out, incount, ratio, final);
}

size_t 
Resampler::resampleInterleaved(float *in, float *out,
                    size_t incount, float ratio,
                    bool final)
{
    return m_d->resampleInterleaved(in, out, incount, ratio, final);
}

void
Resampler::reset()
{
    m_d->reset();
}