MMDVM/MMDVMHost
1
0
Fork 0
mirror of https://github.com/g4klx/MMDVMHost synced 2025-12-21 06:55:52 +08:00
Code Issues Packages Projects Releases Wiki Activity

Simplify writeModem, only 2 loops

Browse Source
This commit is contained in:
Geoffrey Merck
2020-05-31 11:37:18 +02:00
parent 015edf9b81
commit bd1aa20803
1 changed files with 26 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
FMControl.cpp
View File

@@ -83,63 +83,46 @@ 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);
unsigned int nSamples = 0;
float samples[85U]; // 255 / 3;
// Unpack the serial data into float values.
unsigned int pack = 0U;
unsigned char* packPointer = (unsigned char*)&pack;
unsigned short out[168U]; // 84 * 2
unsigned int nOut = 0U;
short unpackedSamples[2U];
for (unsigned int i = 0U; i < bufferLength; i += 3U) {
short sample1 = 0U;
short sample2 = 0U;
unsigned int pack = 0U;
unsigned char* packPointer = (unsigned char*)&pack;
//extract unsigned 12 bit unsigned sample pairs pack into 3 bytes to 16 bit signed
packPointer[0U] = bufferData[i];
packPointer[1U] = bufferData[i + 1U];
packPointer[2U] = bufferData[i + 2U];
unpackedSamples[1U] = short(int(pack & FM_MASK) - 2048);
unpackedSamples[0U] = short(int(pack >> 12) - 2048);
//extract unsigned 12 bit samples to 16 bit signed
sample2 = short(int(pack & FM_MASK) - 2048);
sample1 = short(int(pack >> 12) - 2048);
//process unpacked sample pair
for(unsigned char j = 0U; j < 2U; j++) {
//Convert to float (-1.0 to +1.0)
float sampleFloat = float(unpackedSamples[j]) / 2048.0F;
// Convert from unsigned short (0 - +4095) to float (-1.0 - +1.0)
samples[nSamples++] = float(sample1) / 2048.0F;
samples[nSamples++] = float(sample2) / 2048.0F;
//De-emphasise and remove CTCSS
sampleFloat = m_deemphasis->filter(sampleFloat);
sampleFloat = m_filterStage3->filter(m_filterStage2->filter(m_filterStage1->filter(sampleFloat)));
// Repack the float data to 16 bit unsigned
unsigned short sampleUShort = (unsigned short)((sampleFloat + 1.0F) * 32767.0F + 0.5F);
out[nOut++] = SWAP_BYTES_16(sampleUShort);
}
}
//De-emphasise the data and remove CTCSS
for (unsigned int i = 0U; i < nSamples; i++) {
samples[i] = m_deemphasis->filter(samples[i]);
samples[i] = m_filterStage3->filter(m_filterStage2->filter(m_filterStage1->filter(samples[i])));
}
unsigned short out[170U]; // 85 * 2
unsigned int nOut = 0U;
// Repack the data (8-bit unsigned values containing unsigned 16-bit data)
for (unsigned int i = 0U; i < nSamples; i++) {
unsigned short sample = (unsigned short)((samples[i] + 1.0F) * 32767.0F + 0.5F);
out[nOut++] = SWAP_BYTES_16(sample);//change endianess to network order, transmit MSB first
}
#if defined(DUMP_RF_AUDIO)
if(audiofile != NULL)
fwrite(out, sizeof(unsigned short), nOut, audiofile);
#endif
#if defined(DUMP_RF_AUDIO)
if(audiofile != NULL)
fclose(audiofile);
FILE * audiofile = fopen("./audiodump.bin", "ab");
if(audiofile != NULL) {
fwrite(out, sizeof(unsigned short), nOut, audiofile);
fclose(audiofile);
}
#endif
return m_network->writeData((unsigned char*)out, nOut * sizeof(unsigned short));
}