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Fix unpack, add audio dump

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This commit is contained in:
Geoffrey Merck 2020-05-24 07:43:22 +02:00
parent ad843e7283
commit ed3299a513
2 changed files with 33 additions and 9 deletions
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37
FMControl.cpp
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@ -20,6 +20,11 @@
#include <string>
#if defined(DUMP_RF_AUDIO)
#include <iostream>
#include <fstream>
#endif
const float EMPHASIS_GAIN_DB = 0.0F; //Gain needs to be the same for pre an deeemphasis
const unsigned int FM_MASK = 0x00000FFFU;
@ -38,6 +43,11 @@ CFMControl::~CFMControl()
bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
{
#if defined(DUMP_RF_AUDIO)
std::ofstream audiofile;
audiofile.open("audiodump.bin", std::ios::out | std::ios::app | std::ios::binary);
#endif
assert(data != NULL);
assert(length > 0U);
@ -69,28 +79,33 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
// Unpack the serial data into float values.
for (unsigned int i = 0U; i < bufferLength; i += 3U) {
unsigned short sample1 = 0U;
unsigned short sample2 = 0U;
short sample1 = 0U;
short sample2 = 0U;
unsigned int pack = 0U;
unsigned char* packPointer = (unsigned char*)&pack;
packPointer[1U] = bufferData[i];
packPointer[2U] = bufferData[i + 1U];
packPointer[3U] = bufferData[i + 2U];
packPointer[0U] = bufferData[i];
packPointer[1U] = bufferData[i + 1U];
packPointer[2U] = bufferData[i + 2U];
sample2 = short(pack & FM_MASK);
sample1 = short(pack >> 12);
//extract unsigned 12 bit samples to 16 bit signed
sample2 = short(int(pack & FM_MASK) - 2048);
sample1 = short(int(pack >> 12) - 2048);
// Convert from unsigned short (0 - +4095) to float (-1.0 - +1.0)
samples[nSamples++] = (float(sample1) - 2048.0F) / 2048.0F;
samples[nSamples++] = (float(sample2) - 2048.0F) / 2048.0F;
samples[nSamples++] = float(sample1) / 2048.0F;
samples[nSamples++] = float(sample2) / 2048.0F;
}
//De-emphasise the data and any other processing needed (maybe a low-pass filter to remove the CTCSS)
for (unsigned int i = 0U; i < nSamples; i++)
samples[i] = m_deemphasis.filter(samples[i]);
#if defined(DUMP_RF_AUDIO)
audiofile.write((char*)(void*)samples, nSamples * sizeof(float));
#endif
unsigned short out[170U]; // 85 * 2
unsigned int nOut = 0U;
@ -104,6 +119,10 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
return m_network->writeData((unsigned char*)out, nOut);
}
#if defined(DUMP_RF_AUDIO)
audiofile.close();
#endif
return true;
}

5
FMControl.h
View file

@ -23,6 +23,11 @@
#include "Defines.h"
#include "IIRDirectForm1Filter.h"
// Uncomment this to dump audio to a raw audio file
// The file will be written in same folder as executable
// Toplay the file : aplay -f FLOAT_LE -c1 -r8000 -t raw audiodump.bin
//#define DUMP_RF_AUDIO
class CFMControl {
public:
CFMControl(CFMNetwork* network);