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Merge pull request #593 from F4FXL/FM_Ext

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FM Ext improvements
This commit is contained in:
Jonathan Naylor 2020-05-24 10:10:25 +01:00 committed by GitHub
parent af34d9abc3 8b31cb34ff
commit 12e58d5440
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 39 additions and 14 deletions
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48
FMControl.cpp
View file

@ -20,6 +20,10 @@
#include <string>
#if defined(DUMP_RF_AUDIO)
#include <stdio.h>
#endif
const float EMPHASIS_GAIN_DB = 0.0F; //Gain needs to be the same for pre an deeemphasis
const unsigned int FM_MASK = 0x00000FFFU;
@ -41,6 +45,9 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
assert(data != NULL);
assert(length > 0U);
if (m_network == NULL)
return true;
if (data[0U] == TAG_HEADER)
return true;
@ -50,8 +57,6 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
if (data[0U] != TAG_DATA)
return false;
if (m_network == NULL)
return true;
m_incomingRFAudio.addData(data + 1U, length - 1U);
unsigned int bufferLength = m_incomingRFAudio.dataSize();
@ -59,6 +64,10 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
bufferLength = 255U;
if (bufferLength >= 3U) {
#if defined(DUMP_RF_AUDIO)
FILE * audiofile = fopen("./audiodump.bin", "ab");
#endif
bufferLength = bufferLength - bufferLength % 3U; //round down to nearest multiple of 3
unsigned char bufferData[255U];
m_incomingRFAudio.getData(bufferData, bufferLength);
@ -68,28 +77,34 @@ 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)
if(audiofile != NULL)
fwrite(samples, sizeof(float), nSamples, audiofile);
#endif
unsigned short out[170U]; // 85 * 2
unsigned int nOut = 0U;
@ -100,6 +115,11 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
out[nOut++] = (sample >> 0) & 0xFFU;
}
#if defined(DUMP_RF_AUDIO)
if(audiofile != NULL)
fclose(audiofile);
#endif
return m_network->writeData((unsigned char*)out, nOut);
}
@ -147,9 +167,9 @@ unsigned int CFMControl::readModem(unsigned char* data, unsigned int space)
pack = ((unsigned int)sample1) << 12;
pack |= sample2;
data[j] = packPointer[1U];
data[j + 1U] = packPointer[2U];
data[j + 2U] = packPointer[3U];
data[j] = packPointer[0U];
data[j + 1U] = packPointer[1U];
data[j + 2U] = packPointer[2U];
}
return j;//return the number of bytes written

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);