commit
7be89b91ea
2 changed files with 51 additions and 36 deletions
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@ -21,12 +21,14 @@
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#include <string>
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#define EMPHASIS_GAIN_DB 0 //Gain needs to be the same for pre an deeemphasis
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#define RF_AUDIO_SAMP_RATE 8000
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CFMControl::CFMControl(CFMNetwork* network) :
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m_network(network),
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m_enabled(false),
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m_preemphasis(0.3889703087993727F, -0.3290005228984741F, 0.0F, 1.0F, 0.282029168302153F, 0.0F, EMPHASIS_GAIN_DB),
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m_deemphasis(1.0F, 0.282029168302153F, 0.0F, 0.3889703087993727F, -0.3290005228984741F, 0.0F, EMPHASIS_GAIN_DB)
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// m_preemphasis(0.3889703087993727F, -0.3290005228984741F, 0.0F, 1.0F, 0.282029168302153F, 0.0F, EMPHASIS_GAIN_DB),
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// m_deemphasis(1.0F, 0.282029168302153F, 0.0F, 0.3889703087993727F, -0.3290005228984741F, 0.0F, EMPHASIS_GAIN_DB),
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m_incomingRFAudio(1000U, "Incoming RF FM Audio")
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{
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}
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@ -45,42 +47,54 @@ bool CFMControl::writeModem(const unsigned char* data, unsigned int length)
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float samples[170U];
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unsigned int nSamples = 0U;
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// Unpack the serial data into float values.
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for (unsigned int i = 0U; i < length; i += 3U) {
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unsigned short sample1 = 0U;
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unsigned short sample2 = 0U;
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unsigned int MASK = 0x00000FFFU;
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m_incomingRFAudio.addData(data, length);
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unsigned int bufferLength = m_incomingRFAudio.dataSize();
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unsigned int pack = 0U;
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unsigned char* packPointer = (unsigned char*)&pack;
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if(bufferLength >= 3) {
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bufferLength = bufferLength - bufferLength % 3; //round down to nearest multiple of 3
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unsigned char bufferData[bufferLength];
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m_incomingRFAudio.getData(bufferData, bufferLength);
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packPointer[1U] = data[i];
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packPointer[2U] = data[i + 1U];
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packPointer[3U] = data[i + 2U];
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// Unpack the serial data into float values.
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for (unsigned int i = 0U; i < length; i += 3U) {
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unsigned short sample1 = 0U;
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unsigned short sample2 = 0U;
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unsigned int MASK = 0x00000FFFU;
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sample2 = (short)(pack & MASK);
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sample1 = (short)(pack >> 12);
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unsigned int pack = 0U;
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unsigned char* packPointer = (unsigned char*)&pack;
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// Convert from unsigned short (0 - +4095) to float (-1.0 - +1.0)
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samples[nSamples++] = (float(sample1) - 2048.0F) / 2048.0F;
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samples[nSamples++] = (float(sample2) - 2048.0F) / 2048.0F;
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packPointer[1U] = bufferData[i];
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packPointer[2U] = bufferData[i + 1U];
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packPointer[3U] = bufferData[i + 2U];
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sample2 = (short)(pack & MASK);
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sample1 = (short)(pack >> 12);
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// Convert from unsigned short (0 - +4095) to float (-1.0 - +1.0)
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samples[nSamples++] = (float(sample1) - 2048.0F) / 2048.0F;
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samples[nSamples++] = (float(sample2) - 2048.0F) / 2048.0F;
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}
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// De-emphasise the data and any other processing needed (maybe a low-pass filter to remove the CTCSS)
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// for (unsigned int i = 0U; i < nSamples; i++)
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// samples[i] = m_deemphasis.filter(samples[i]);
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unsigned char out[350U];
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unsigned int nOut = 0U;
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// Repack the data (8-bit unsigned values containing unsigned 16-bit data)
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for (unsigned int i = 0U; i < nSamples; i++) {
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unsigned short sample = (unsigned short)((samples[i] + 1.0F) * 32767.0F + 0.5F);
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out[nOut++] = (sample >> 8) & 0xFFU;
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out[nOut++] = (sample >> 0) & 0xFFU;
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}
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return m_network->write(out, nOut);
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}
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// De-emphasise the data and any other processing needed (maybe a low-pass filter to remove the CTCSS)
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for (unsigned int i = 0U; i < nSamples; i++)
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samples[i] = m_deemphasis.filter(samples[i]);
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unsigned char out[350U];
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unsigned int nOut = 0U;
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// Repack the data (8-bit unsigned values containing unsigned 16-bit data)
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for (unsigned int i = 0U; i < nSamples; i++) {
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unsigned short sample = (unsigned short)((samples[i] + 1.0F) * 32767.0F + 0.5F);
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out[nOut++] = (sample >> 8) & 0xFFU;
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out[nOut++] = (sample >> 0) & 0xFFU;
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}
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return m_network->write(out, nOut);
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return 0U;
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}
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unsigned int CFMControl::readModem(unsigned char* data, unsigned int space)
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@ -105,8 +119,8 @@ unsigned int CFMControl::readModem(unsigned char* data, unsigned int space)
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}
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// Pre-emphasise the data and other stuff.
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for (unsigned int i = 0U; i < nSamples; i++)
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samples[i] = m_preemphasis.filter(samples[i]);
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// for (unsigned int i = 0U; i < nSamples; i++)
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// samples[i] = m_preemphasis.filter(samples[i]);
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// Pack the floating point data (+1.0 to -1.0) to packed 12-bit samples (+2047 - -2048)
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unsigned int pack = 0U;
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@ -39,8 +39,9 @@ public:
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private:
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CFMNetwork* m_network;
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bool m_enabled;
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CIIRDirectForm1Filter m_preemphasis;
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CIIRDirectForm1Filter m_deemphasis;
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// CIIRDirectForm1Filter m_preemphasis;
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// CIIRDirectForm1Filter m_deemphasis;
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CRingBuffer<unsigned char> m_incomingRFAudio;
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};
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#endif
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