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MMDVM
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Merge pull request #251 from F4FXL/FM_Ext 

Remove Union for sample packing
This commit is contained in:
Jonathan Naylor 2020-05-08 16:30:06 +01:00 committed by GitHub
parent e7ff0d1898 bb731e7890
commit 604957b3e2
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 20 additions and 18 deletions
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30
FMDownsampler.cpp
View File

@ -23,29 +23,31 @@
CFMDownsampler::CFMDownsampler(uint16_t length) :
m_ringBuffer(length),//length might need tweaking
m_packIndex(0),
m_downSampleIndex(0)
m_samplePack(0U),
m_samplePackPointer(NULL),
m_packIndex(0U),
m_downSampleIndex(0U)
{
m_samplePack = 0;
m_samplePackPointer = &m_samplePack;
}
void CFMDownsampler::addSample(q15_t sample)
{
//only take one of three samples
if(m_downSampleIndex == 0) {
if(m_downSampleIndex == 0U) {
switch(m_packIndex){
case 0:
m_samplePack = int32_t(sample) << 12;
m_samplePack = uint32_t(sample) << 12;
break;
case 1:{
m_samplePack |= int32_t(sample);
m_samplePack |= uint32_t(sample);
//we did not use MSB; skip it
m_ringBuffer.put(m_samplePackBytes[1]);
m_ringBuffer.put(m_samplePackBytes[2]);
m_ringBuffer.put(m_samplePackBytes[3]);
m_ringBuffer.put(m_samplePackPointer[1U]);
m_ringBuffer.put(m_samplePackPointer[2U]);
m_ringBuffer.put(m_samplePackPointer[3U]);
m_samplePack = 0;
m_samplePack = 0;//reset the sample pack
}
break;
default:
@ -53,11 +55,11 @@ void CFMDownsampler::addSample(q15_t sample)
break;
}
m_packIndex++;
if(m_packIndex >= 2)
m_packIndex = 0;
if(m_packIndex >= 2U)//did we pack to samples ?
m_packIndex = 0U;
}
m_downSampleIndex++;
if(m_downSampleIndex >= 3)
m_downSampleIndex = 0;
if(m_downSampleIndex >= 3U)
m_downSampleIndex = 0U;
}

8
FMDownsampler.h
View File

@ -32,10 +32,10 @@ public:
private:
CFMDownsampleRB m_ringBuffer;
union {
int32_t m_samplePack;
int8_t m_samplePackBytes[4];
};
uint32_t m_samplePack;
uint32_t *m_samplePackPointer;
uint8_t m_packIndex;
uint8_t m_downSampleIndex;
};