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Code Issues Projects Releases Wiki Activity

Audio Input: quarter sample rate heterodyne for mono signals

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This commit is contained in:
f4exb
2020-11-13 19:55:09 +01:00
parent 6e3add76e3
commit 9cdcfeef70
7 changed files with 70 additions and 34 deletions
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plugins/samplesource/audioinput/audioinputworker.cpp
+43 -17
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@@ -33,7 +33,8 @@ AudioInputWorker::AudioInputWorker(SampleSinkFifo* sampleFifo, AudioFifo *fifo,
m_log2Decim(0),
m_iqMapping(AudioInputSettings::IQMapping::L),
m_convertBuffer(m_convBufSamples),
m_sampleFifo(sampleFifo)
m_sampleFifo(sampleFifo),
m_quNCOPhase(0)
{
}
@@ -56,20 +57,40 @@ void AudioInputWorker::stopWork()
void AudioInputWorker::workIQ(unsigned int nbRead)
{
// Map between left and right audio channels and IQ channels
if (m_iqMapping == AudioInputSettings::IQMapping::L)
{
for (uint32_t i = 0; i < nbRead; i++)
m_buf[i*2+1] = 0;
}
else if (m_iqMapping == AudioInputSettings::IQMapping::R)
if ((m_iqMapping == AudioInputSettings::IQMapping::L) || // mono
(m_iqMapping == AudioInputSettings::IQMapping::R))
{
for (uint32_t i = 0; i < nbRead; i++)
{
m_buf[i*2] = m_buf[i*2+1];
m_buf[i*2+1] = 0;
qint16 r = m_buf[i*2 + (m_iqMapping == AudioInputSettings::IQMapping::R ? 1 : 0)]; // real sample
if (m_quNCOPhase == 0) // 0
{
m_buf[i*2] = r; // 1
m_buf[i*2+1] = 0; // 0
m_quNCOPhase = 1; // next phase
}
else if (m_quNCOPhase == 1) // -pi/2
{
m_buf[i*2] = 0; // 0
m_buf[i*2+1] = -r; // -1
m_quNCOPhase = 2; // next phase
}
else if (m_quNCOPhase == 2) // pi or -pi
{
m_buf[i*2] = -r; // -1
m_buf[i*2+1] = 0; // 0
m_quNCOPhase = 3; // next phase
}
else if (m_quNCOPhase == 3) // pi/2
{
m_buf[i*2] = 0; // 0
m_buf[i*2+1] = r; // 1
m_quNCOPhase = 0; // next phase
}
}
}
else if (m_iqMapping == AudioInputSettings::IQMapping::LR)
else if (m_iqMapping == AudioInputSettings::IQMapping::LR) // stereo - reverse
{
for (uint32_t i = 0; i < nbRead; i++)
{
@@ -79,30 +100,35 @@ void AudioInputWorker::workIQ(unsigned int nbRead)
}
}
decimate(m_buf, nbRead);
}
void AudioInputWorker::decimate(qint16 *buf, unsigned int nbRead)
{
SampleVector::iterator it = m_convertBuffer.begin();
switch (m_log2Decim)
{
case 0:
m_decimatorsIQ.decimate1(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate1(&it, buf, 2*nbRead);
break;
case 1:
m_decimatorsIQ.decimate2_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate2_cen(&it, buf, 2*nbRead);
break;
case 2:
m_decimatorsIQ.decimate4_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate4_cen(&it, buf, 2*nbRead);
break;
case 3:
m_decimatorsIQ.decimate8_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate8_cen(&it, buf, 2*nbRead);
break;
case 4:
m_decimatorsIQ.decimate16_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate16_cen(&it, buf, 2*nbRead);
break;
case 5:
m_decimatorsIQ.decimate32_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate32_cen(&it, buf, 2*nbRead);
break;
case 6:
m_decimatorsIQ.decimate64_cen(&it, m_buf, 2*nbRead);
m_decimatorsIQ.decimate64_cen(&it, buf, 2*nbRead);
break;
default:
break;