sdrangel/sdrbase/audio/audioresampler.cpp

96 wiersze
3.1 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2019 F4EXB //
// written by Edouard Griffiths //
// //
// 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 as 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#include "audioresampler.h"
AudioResampler::AudioResampler() :
m_decimation(1),
m_decimationCount(0)
{}
AudioResampler::~AudioResampler()
{}
void AudioResampler::setDecimation(uint32_t decimation)
{
m_decimation = decimation == 0 ? 1 : decimation;
}
void AudioResampler::setAudioFilters(int srHigh, int srLow, int fcLow, int fcHigh, float gain)
{
srHigh = (srHigh <= 100 ? 100 : srHigh);
srLow = (srLow <= 0 ? 1 : srLow);
srLow = srLow > srHigh - 50 ? srHigh - 50 : srLow;
fcLow = fcLow < 0 ? 0 : fcLow;
fcHigh = fcHigh < 100 ? 100 : fcHigh;
fcLow = fcLow > fcHigh - 100 ? fcHigh - 100 : fcLow;
m_audioFilter.setDecimFilters(srHigh, srLow, fcHigh, fcLow, gain);
}
bool AudioResampler::downSample(qint16 sampleIn, qint16& sampleOut)
{
if (m_decimation == 1)
{
sampleOut = sampleIn;
return true;
}
if (m_decimationCount >= m_decimation - 1)
{
float lpSample = m_audioFilter.run(sampleIn / 32768.0f);
sampleOut = lpSample * 32768.0f;
m_decimationCount = 0;
return true;
}
else
{
m_decimationCount++;
return false;
}
}
bool AudioResampler::upSample(qint16 sampleIn, qint16& sampleOut)
{
float lpSample;
if (m_decimation == 1)
{
sampleOut = sampleIn;
return true;
}
if (m_decimationCount >= m_decimation - 1)
{
m_decimationCount = 0;
lpSample = m_audioFilter.run(sampleIn / 32768.0f);
sampleOut = lpSample * 32768.0f;
return true;
}
else
{
m_decimationCount++;
lpSample = m_audioFilter.run(0.0f);
sampleOut = lpSample * 32768.0f;
return false;
}
}