samplerateconverter.cpp

/*
 *  Copyright (C) 2008 Savoir-Faire Linux inc.
 *  Author: Emmanuel Milou <emmanuel.milou@savoirfairelinux.com>
 * 
 *  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 3 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "samplerateconverter.h"

SamplerateConverter::SamplerateConverter( void )
        : _frequence(Manager::instance().getConfigInt( AUDIO , ALSA_SAMPLE_RATE )) //44100
        , _framesize(Manager::instance().getConfigInt( AUDIO , ALSA_FRAME_SIZE ))
        , _floatBufferDownMic(NULL)
        , _floatBufferUpMic(NULL)
        , _src_state_mic(NULL)
        , _floatBufferDownSpkr(NULL)
        , _floatBufferUpSpkr(NULL)
        , _src_state_spkr(NULL)
        , _src_err(0)
{
  init();
}

SamplerateConverter::SamplerateConverter( int freq , int fs )
        : _frequence(freq) 
        , _framesize(fs)
        , _floatBufferDownMic(NULL)
        , _floatBufferUpMic(NULL)
        , _src_state_mic(NULL)
        , _floatBufferDownSpkr(NULL)
        , _floatBufferUpSpkr(NULL)
        , _src_state_spkr(NULL)
        , _src_err(0)       
{ 
  init();
}

SamplerateConverter::~SamplerateConverter( void ) {

  delete [] _floatBufferUpMic; _floatBufferUpMic = NULL;
  delete [] _floatBufferDownMic; _floatBufferDownMic = NULL;

  delete [] _floatBufferUpSpkr; _floatBufferUpSpkr = NULL;
  delete [] _floatBufferDownSpkr; _floatBufferDownSpkr = NULL;

  // libSamplerateConverter-related
  _src_state_mic  = src_delete(_src_state_mic);
  _src_state_spkr = src_delete(_src_state_spkr);
}

void SamplerateConverter::init( void ) {
  
  // libSamplerateConverter-related
  // Set the converter type for the upsampling and the downsampling
  // interpolator SRC_SINC_BEST_QUALITY
  _src_state_mic  = src_new(SRC_SINC_BEST_QUALITY, 1, &_src_err);
  _src_state_spkr = src_new(SRC_SINC_BEST_QUALITY, 1, &_src_err);

  int nbSamplesMax = (int) ( getFrequence() * getFramesize() / 1000 );
  _floatBufferDownMic  = new float32[nbSamplesMax];
  _floatBufferUpMic = new float32[nbSamplesMax];
  _floatBufferDownSpkr  = new float32[nbSamplesMax];
  _floatBufferUpSpkr = new float32[nbSamplesMax];
}

//TODO Add ifdef for int16 or float32 type
int SamplerateConverter::upsampleData(  SFLDataFormat* dataIn , SFLDataFormat* dataOut, int samplerate1 , int samplerate2 , int nbSamples ){
  
  double upsampleFactor = (double)samplerate2 / samplerate1 ;
  int nbSamplesMax = (int) ( samplerate2 * getFramesize() / 1000 );
  if( upsampleFactor != 1 && dataIn != NULL )
  {
    SRC_DATA src_data;
    src_data.data_in = _floatBufferDownSpkr;
    src_data.data_out = _floatBufferUpSpkr;
    src_data.input_frames = nbSamples;
    src_data.output_frames = (int) floor(upsampleFactor * nbSamples);
    src_data.src_ratio = upsampleFactor;
    src_data.end_of_input = 0; // More data will come
  //_debug("upsample %d %d %f %d\n" , src_data.input_frames , src_data.output_frames, src_data.src_ratio , nbSamples);
    src_short_to_float_array( dataIn , _floatBufferDownSpkr, nbSamples);
  //_debug("upsample %d %f %d\n" ,  src_data.output_frames, src_data.src_ratio , nbSamples);
    src_process(_src_state_spkr, &src_data);
  //_debug("upsample %d %d %d\n" , samplerate1, samplerate2 , nbSamples);
    nbSamples  = ( src_data.output_frames_gen > nbSamplesMax) ? nbSamplesMax : src_data.output_frames_gen;		
    src_float_to_short_array(_floatBufferUpSpkr, dataOut, nbSamples);
  //_debug("upsample %d %d %d\n" , samplerate1, samplerate2 , nbSamples);
  }
  return nbSamples;
}

//TODO Add ifdef for int16 or float32 type
int SamplerateConverter::downsampleData(  SFLDataFormat* dataIn , SFLDataFormat* dataOut , int samplerate1 , int samplerate2 , int nbSamples ){

  double downsampleFactor = (double)samplerate1 / samplerate2;
  //_debug("factor = %f\n" , downsampleFactor);
  int nbSamplesMax = (int) ( samplerate1 * getFramesize() / 1000 );
  if ( downsampleFactor != 1)
  {
    SRC_DATA src_data;	
    src_data.data_in = _floatBufferUpMic;
    src_data.data_out = _floatBufferDownMic;
    src_data.input_frames = nbSamples;
    src_data.output_frames = (int) floor(downsampleFactor * nbSamples);
    src_data.src_ratio = downsampleFactor;
    src_data.end_of_input = 0; // More data will come
  //_debug("downsample %d %f %d\n" ,  src_data.output_frames, src_data.src_ratio , nbSamples);
    src_short_to_float_array( dataIn, _floatBufferUpMic, nbSamples );
  //_debug("downsample %d %f %d\n" ,  src_data.output_frames, src_data.src_ratio , nbSamples);
    src_process(_src_state_mic, &src_data);
  //_debug("downsample %d %f %d\n" ,  src_data.output_frames, src_data.src_ratio , nbSamples);
    nbSamples  = ( src_data.output_frames_gen > nbSamplesMax) ? nbSamplesMax : src_data.output_frames_gen;
  //_debug("downsample %d %f %d\n" ,  src_data.output_frames, src_data.src_ratio , nbSamples);
    src_float_to_short_array( _floatBufferDownMic , dataOut , nbSamples );
  }
  return nbSamples;
}