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main.cpp
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main.cpp
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/*! \file main.cpp
* \brief Send/Receive data through sound
* \author Georgi Gerganov
*/
#include "reed-solomon/rs.hpp"
#include <SDL2/SDL.h>
#include <SDL2/SDL_audio.h>
#include <cmath>
#include <cstdio>
#include <array>
#include <string>
#include <chrono>
#include <ctime>
#include <algorithm>
#include <map>
#include <complex>
#ifndef M_PI
#define M_PI 3.14159265358979323846f
#endif
#ifdef __EMSCRIPTEN__
#include "build_timestamp.h"
#include "emscripten/emscripten.h"
#else
#include <thread>
#include <iostream>
#endif
#ifdef main
#undef main
#endif
static char *g_captureDeviceName = nullptr;
static int g_captureId = -1;
static int g_playbackId = -1;
static bool g_isInitialized = false;
static int g_totalBytesCaptured = 0;
static SDL_AudioDeviceID devid_in = 0;
static SDL_AudioDeviceID devid_out = 0;
struct DataRxTx;
static DataRxTx *g_data = nullptr;
namespace {
constexpr double kBaseSampleRate = 48000.0;
constexpr auto kMaxSamplesPerFrame = 1024;
constexpr auto kMaxDataBits = 256;
constexpr auto kMaxDataSize = 256;
constexpr auto kMaxLength = 140;
constexpr auto kMaxSpectrumHistory = 4;
constexpr auto kMaxRecordedFrames = 64*10;
constexpr auto kDefaultFixedLength = 82;
// FFT routines taken from https://stackoverflow.com/a/37729648/4039976
int log2(int N) {
int k = N, i = 0;
while(k) {
k >>= 1;
i++;
}
return i - 1;
}
int check(int n) {
return n > 0 && (n & (n - 1)) == 0;
}
int reverse(int N, int n) {
int j, p = 0;
for(j = 1; j <= log2(N); j++) {
if(n & (1 << (log2(N) - j)))
p |= 1 << (j - 1);
}
return p;
}
void ordina(std::complex<float>* f1, int N) {
std::complex<float> f2[kMaxSamplesPerFrame];
for(int i = 0; i < N; i++)
f2[i] = f1[reverse(N, i)];
for(int j = 0; j < N; j++)
f1[j] = f2[j];
}
void transform(std::complex<float>* f, int N) {
ordina(f, N); //first: reverse order
std::complex<float> *W;
W = (std::complex<float> *)malloc(N / 2 * sizeof(std::complex<float>));
W[1] = std::polar(1., -2. * M_PI / N);
W[0] = 1;
for(int i = 2; i < N / 2; i++)
W[i] = pow(W[1], i);
int n = 1;
int a = N / 2;
for(int j = 0; j < log2(N); j++) {
for(int i = 0; i < N; i++) {
if(!(i & n)) {
std::complex<float> temp = f[i];
std::complex<float> Temp = W[(i * a) % (n * a)] * f[i + n];
f[i] = temp + Temp;
f[i + n] = temp - Temp;
}
}
n *= 2;
a = a / 2;
}
free(W);
}
void FFT(std::complex<float>* f, int N, float d) {
transform(f, N);
for(int i = 0; i < N; i++)
f[i] *= d; //multiplying by step
}
void FFT(float * src, std::complex<float>* dst, int N, float d) {
for (int i = 0; i < N; ++i) {
dst[i].real(src[i]);
dst[i].imag(0);
}
FFT(dst, N, d);
}
enum TxMode {
FixedLength = 0,
VariableLength,
};
using AmplitudeData = std::array<float, kMaxSamplesPerFrame>;
using AmplitudeData16 = std::array<int16_t, kMaxRecordedFrames*kMaxSamplesPerFrame>;
using SpectrumData = std::array<float, kMaxSamplesPerFrame>;
using RecordedData = std::array<float, kMaxRecordedFrames*kMaxSamplesPerFrame>;
inline void addAmplitudeSmooth(const AmplitudeData & src, AmplitudeData & dst, float scalar, int startId, int finalId, int cycleMod, int nPerCycle) {
int nTotal = nPerCycle*finalId;
float frac = 0.15f;
float ds = frac*nTotal;
float ids = 1.0f/ds;
int nBegin = frac*nTotal;
int nEnd = (1.0f - frac)*nTotal;
for (int i = startId; i < finalId; i++) {
float k = cycleMod*finalId + i;
if (k < nBegin) {
dst[i] += scalar*src[i]*(k*ids);
} else if (k > nEnd) {
dst[i] += scalar*src[i]*(((float)(nTotal) - k)*ids);
} else {
dst[i] += scalar*src[i];
}
}
}
template <class T>
float getTime_ms(const T & tStart, const T & tEnd) {
return ((float)(std::chrono::duration_cast<std::chrono::microseconds>(tEnd - tStart).count()))/1000.0;
}
int getECCBytesForLength(int len) {
return std::max(4, 2*(len/5));
}
}
struct DataRxTx {
DataRxTx(int aSampleRateOut, int aSampleRate, int aSamplesPerFrame, int aSampleSizeB, const char * text) {
sampleSizeBytes = aSampleSizeB;
sampleRate = aSampleRate;
sampleRateOut = aSampleRateOut;
samplesPerFrame = aSamplesPerFrame;
init(strlen(text), text);
}
void init(int textLength, const char * stext) {
if (textLength > ::kMaxLength) {
printf("Truncating data from %d to 140 bytes\n", textLength);
textLength = ::kMaxLength;
}
const uint8_t * text = reinterpret_cast<const uint8_t *>(stext);
frameId = 0;
nIterations = 0;
hasData = false;
isamplesPerFrame = 1.0f/samplesPerFrame;
sendVolume = ((double)(paramVolume))/100.0f;
hzPerFrame = sampleRate/samplesPerFrame;
ihzPerFrame = 1.0/hzPerFrame;
framesPerTx = paramFramesPerTx;
nDataBitsPerTx = paramBytesPerTx*8;
nECCBytesPerTx = (txMode == ::TxMode::FixedLength) ? paramECCBytesPerTx : getECCBytesForLength(textLength);
framesToAnalyze = 0;
framesLeftToAnalyze = 0;
framesToRecord = 0;
framesLeftToRecord = 0;
nBitsInMarker = 16;
nMarkerFrames = 16;
nPostMarkerFrames = 0;
sendDataLength = (txMode == ::TxMode::FixedLength) ? ::kDefaultFixedLength : textLength + 3;
d0 = paramFreqDelta/2;
freqDelta_hz = hzPerFrame*paramFreqDelta;
freqStart_hz = hzPerFrame*paramFreqStart;
if (paramFreqDelta == 1) {
d0 = 1;
freqDelta_hz *= 2;
}
outputBlock.fill(0);
encodedData.fill(0);
for (int k = 0; k < (int) phaseOffsets.size(); ++k) {
phaseOffsets[k] = (M_PI*k)/(nDataBitsPerTx);
}
#ifdef __EMSCRIPTEN__
std::random_shuffle(phaseOffsets.begin(), phaseOffsets.end());
#endif
for (int k = 0; k < (int) dataBits.size(); ++k) {
double freq = freqStart_hz + freqDelta_hz*k;
dataFreqs_hz[k] = freq;
double phaseOffset = phaseOffsets[k];
double curHzPerFrame = sampleRateOut/samplesPerFrame;
double curIHzPerFrame = 1.0/curHzPerFrame;
for (int i = 0; i < samplesPerFrame; i++) {
double curi = i;
bit1Amplitude[k][i] = std::sin((2.0*M_PI)*(curi*isamplesPerFrame)*(freq*curIHzPerFrame) + phaseOffset);
}
for (int i = 0; i < samplesPerFrame; i++) {
double curi = i;
bit0Amplitude[k][i] = std::sin((2.0*M_PI)*(curi*isamplesPerFrame)*((freq + hzPerFrame*d0)*curIHzPerFrame) + phaseOffset);
}
}
if (rsData) delete rsData;
if (rsLength) delete rsLength;
if (txMode == ::TxMode::FixedLength) {
rsData = new RS::ReedSolomon(kDefaultFixedLength, nECCBytesPerTx);
} else {
rsData = new RS::ReedSolomon(textLength, nECCBytesPerTx);
rsLength = new RS::ReedSolomon(1, 2);
}
if (textLength > 0) {
static std::array<char, ::kMaxDataSize> theData;
theData.fill(0);
if (txMode == ::TxMode::FixedLength) {
for (int i = 0; i < textLength; ++i) theData[i] = text[i];
rsData->Encode(theData.data(), encodedData.data());
} else {
theData[0] = textLength;
for (int i = 0; i < textLength; ++i) theData[i + 1] = text[i];
rsData->Encode(theData.data() + 1, encodedData.data() + 3);
rsLength->Encode(theData.data(), encodedData.data());
}
hasData = true;
}
// Rx
receivingData = false;
analyzingData = false;
sampleAmplitude.fill(0);
sampleSpectrum.fill(0);
for (auto & s : sampleAmplitudeHistory) {
s.fill(0);
}
rxData.fill(0);
for (int i = 0; i < samplesPerFrame; ++i) {
fftOut[i].real(0.0f);
fftOut[i].imag(0.0f);
}
}
void send() {
int samplesPerFrameOut = (sampleRateOut/sampleRate)*samplesPerFrame;
if (sampleRateOut != sampleRate) {
printf("Resampling from %d Hz to %d Hz\n", (int) sampleRate, (int) sampleRateOut);
}
while(hasData) {
int nBytesPerTx = nDataBitsPerTx/8;
std::fill(outputBlock.begin(), outputBlock.end(), 0.0f);
std::uint16_t nFreq = 0;
if (sampleRateOut != sampleRate) {
for (int k = 0; k < nDataBitsPerTx; ++k) {
double freq = freqStart_hz + freqDelta_hz*k;
double phaseOffset = phaseOffsets[k];
double curHzPerFrame = sampleRateOut/samplesPerFrame;
double curIHzPerFrame = 1.0/curHzPerFrame;
for (int i = 0; i < samplesPerFrameOut; i++) {
double curi = (i + frameId*samplesPerFrameOut);
bit1Amplitude[k][i] = std::sin((2.0*M_PI)*(curi*isamplesPerFrame)*(freq*curIHzPerFrame) + phaseOffset);
}
for (int i = 0; i < samplesPerFrameOut; i++) {
double curi = (i + frameId*samplesPerFrameOut);
bit0Amplitude[k][i] = std::sin((2.0*M_PI)*(curi*isamplesPerFrame)*((freq + hzPerFrame*d0)*curIHzPerFrame) + phaseOffset);
}
}
}
if (frameId < nMarkerFrames) {
nFreq = nBitsInMarker;
for (int i = 0; i < nBitsInMarker; ++i) {
if (i%2 == 0) {
::addAmplitudeSmooth(bit1Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, frameId, nMarkerFrames);
} else {
::addAmplitudeSmooth(bit0Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, frameId, nMarkerFrames);
}
}
} else if (frameId < nMarkerFrames + nPostMarkerFrames) {
nFreq = nBitsInMarker;
for (int i = 0; i < nBitsInMarker; ++i) {
if (i%2 == 0) {
::addAmplitudeSmooth(bit0Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, frameId - nMarkerFrames, nPostMarkerFrames);
} else {
::addAmplitudeSmooth(bit1Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, frameId - nMarkerFrames, nPostMarkerFrames);
}
}
} else if (frameId <
(nMarkerFrames + nPostMarkerFrames) +
((sendDataLength + nECCBytesPerTx)/nBytesPerTx + 2)*framesPerTx) {
int dataOffset = frameId - nMarkerFrames - nPostMarkerFrames;
int cycleModMain = dataOffset%framesPerTx;
dataOffset /= framesPerTx;
dataOffset *= nBytesPerTx;
dataBits.fill(0);
if (paramFreqDelta > 1) {
for (int j = 0; j < nBytesPerTx; ++j) {
for (int i = 0; i < 8; ++i) {
dataBits[j*8 + i] = encodedData[dataOffset + j] & (1 << i);
}
}
for (int k = 0; k < nDataBitsPerTx; ++k) {
++nFreq;
if (dataBits[k] == false) {
::addAmplitudeSmooth(bit0Amplitude[k], outputBlock, sendVolume, 0, samplesPerFrameOut, cycleModMain, framesPerTx);
continue;
}
::addAmplitudeSmooth(bit1Amplitude[k], outputBlock, sendVolume, 0, samplesPerFrameOut, cycleModMain, framesPerTx);
}
} else {
for (int j = 0; j < nBytesPerTx; ++j) {
{
uint8_t d = encodedData[dataOffset + j] & 15;
dataBits[(2*j + 0)*16 + d] = 1;
}
{
uint8_t d = encodedData[dataOffset + j] & 240;
dataBits[(2*j + 1)*16 + (d >> 4)] = 1;
}
}
for (int k = 0; k < 2*nBytesPerTx*16; ++k) {
if (dataBits[k] == 0) continue;
++nFreq;
if (k%2) {
::addAmplitudeSmooth(bit0Amplitude[k/2], outputBlock, sendVolume, 0, samplesPerFrameOut, cycleModMain, framesPerTx);
} else {
::addAmplitudeSmooth(bit1Amplitude[k/2], outputBlock, sendVolume, 0, samplesPerFrameOut, cycleModMain, framesPerTx);
}
}
}
} else if (txMode == ::TxMode::VariableLength && frameId <
(nMarkerFrames + nPostMarkerFrames) +
((sendDataLength + nECCBytesPerTx)/nBytesPerTx + 2)*framesPerTx +
(nMarkerFrames)) {
nFreq = nBitsInMarker;
int fId = frameId - ((nMarkerFrames + nPostMarkerFrames) + ((sendDataLength + nECCBytesPerTx)/nBytesPerTx + 2)*framesPerTx);
for (int i = 0; i < nBitsInMarker; ++i) {
if (i%2 == 0) {
::addAmplitudeSmooth(bit0Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, fId, nMarkerFrames);
} else {
::addAmplitudeSmooth(bit1Amplitude[i], outputBlock, sendVolume, 0, samplesPerFrameOut, fId, nMarkerFrames);
}
}
} else {
textToSend = "";
hasData = false;
}
if (nFreq == 0) nFreq = 1;
float scale = 1.0f/nFreq;
for (int i = 0; i < samplesPerFrameOut; ++i) {
outputBlock[i] *= scale;
}
for (int i = 0; i < samplesPerFrameOut; ++i) {
outputBlock16[frameId*samplesPerFrameOut + i] = std::round(32000.0*outputBlock[i]);
}
++frameId;
}
SDL_QueueAudio(devid_out, outputBlock16.data(), 2*frameId*samplesPerFrameOut);
}
void receive() {
static int nCalls = 0;
static float tSum_ms = 0.0f;
auto tCallStart = std::chrono::high_resolution_clock::now();
if (needUpdate) {
init(0, "");
needUpdate = false;
}
while (hasData == false) {
// read capture data
int nBytesRecorded = SDL_DequeueAudio(devid_in, sampleAmplitude.data(), samplesPerFrame*sampleSizeBytes);
if (nBytesRecorded != 0) {
{
sampleAmplitudeHistory[historyId] = sampleAmplitude;
if (++historyId >= ::kMaxSpectrumHistory) {
historyId = 0;
}
if (historyId == 0 && (receivingData == false || (receivingData && txMode == ::TxMode::VariableLength))) {
std::fill(sampleAmplitudeAverage.begin(), sampleAmplitudeAverage.end(), 0.0f);
for (auto & s : sampleAmplitudeHistory) {
for (int i = 0; i < samplesPerFrame; ++i) {
sampleAmplitudeAverage[i] += s[i];
}
}
float norm = 1.0f/::kMaxSpectrumHistory;
for (int i = 0; i < samplesPerFrame; ++i) {
sampleAmplitudeAverage[i] *= norm;
}
// calculate spectrum
std::copy(sampleAmplitudeAverage.begin(), sampleAmplitudeAverage.begin() + samplesPerFrame, fftIn.data());
FFT(fftIn.data(), fftOut.data(), samplesPerFrame, 1.0);
double fsum = 0.0;
for (int i = 0; i < samplesPerFrame; ++i) {
sampleSpectrum[i] = (fftOut[i].real()*fftOut[i].real() + fftOut[i].imag()*fftOut[i].imag());
fsum += sampleSpectrum[i];
}
for (int i = 1; i < samplesPerFrame/2; ++i) {
sampleSpectrum[i] += sampleSpectrum[samplesPerFrame - i];
}
if (fsum < 1e-10) {
g_totalBytesCaptured = 0;
} else {
g_totalBytesCaptured += nBytesRecorded;
}
}
if (framesLeftToRecord > 0) {
std::copy(sampleAmplitude.begin(),
sampleAmplitude.begin() + samplesPerFrame,
recordedAmplitude.data() + (framesToRecord - framesLeftToRecord)*samplesPerFrame);
if (--framesLeftToRecord <= 0) {
std::fill(sampleSpectrum.begin(), sampleSpectrum.end(), 0.0f);
analyzingData = true;
}
}
}
if (analyzingData) {
int nBytesPerTx = nDataBitsPerTx/8;
int stepsPerFrame = 16;
int step = samplesPerFrame/stepsPerFrame;
int offsetStart = 0;
framesToAnalyze = nMarkerFrames*stepsPerFrame;
framesLeftToAnalyze = framesToAnalyze;
bool isValid = false;
//for (int ii = nMarkerFrames*stepsPerFrame/2; ii < (nMarkerFrames + nPostMarkerFrames)*stepsPerFrame; ++ii) {
for (int ii = nMarkerFrames*stepsPerFrame - 1; ii >= nMarkerFrames*stepsPerFrame/2; --ii) {
offsetStart = ii;
bool knownLength = txMode == ::TxMode::FixedLength;
int encodedOffset = (txMode == ::TxMode::FixedLength) ? 0 : 3;
for (int itx = 0; itx < 1024; ++itx) {
int offsetTx = offsetStart + itx*framesPerTx*stepsPerFrame;
if (offsetTx >= recvDuration_frames*stepsPerFrame) {
break;
}
std::copy(
recordedAmplitude.begin() + offsetTx*step,
recordedAmplitude.begin() + offsetTx*step + samplesPerFrame, fftIn.data());
for (int k = 1; k < framesPerTx-1; ++k) {
for (int i = 0; i < samplesPerFrame; ++i) {
fftIn[i] += recordedAmplitude[(offsetTx + k*stepsPerFrame)*step + i];
}
}
FFT(fftIn.data(), fftOut.data(), samplesPerFrame, 1.0);
for (int i = 0; i < samplesPerFrame; ++i) {
sampleSpectrum[i] = (fftOut[i].real()*fftOut[i].real() + fftOut[i].imag()*fftOut[i].imag());
}
for (int i = 1; i < samplesPerFrame/2; ++i) {
sampleSpectrum[i] += sampleSpectrum[samplesPerFrame - i];
}
uint8_t curByte = 0;
if (paramFreqDelta > 1) {
for (int i = 0; i < nDataBitsPerTx; ++i) {
int k = i%8;
int bin = std::round(dataFreqs_hz[i]*ihzPerFrame);
if (sampleSpectrum[bin] > 1*sampleSpectrum[bin + d0]) {
curByte += 1 << k;
} else if (sampleSpectrum[bin + d0] > 1*sampleSpectrum[bin]) {
} else {
}
if (k == 7) {
encodedData[itx*nBytesPerTx + i/8] = curByte;
curByte = 0;
}
}
} else {
for (int i = 0; i < 2*nBytesPerTx; ++i) {
int bin = std::round(dataFreqs_hz[0]*ihzPerFrame) + i*16;
int kmax = 0;
double amax = 0.0;
for (int k = 0; k < 16; ++k) {
if (sampleSpectrum[bin + k] > amax) {
kmax = k;
amax = sampleSpectrum[bin + k];
}
}
if (i%2) {
curByte += (kmax << 4);
encodedData[itx*nBytesPerTx + i/2] = curByte;
curByte = 0;
} else {
curByte = kmax;
}
}
}
if (txMode == ::TxMode::VariableLength) {
if (itx*nBytesPerTx > 3 && knownLength == false) {
if ((rsLength->Decode(encodedData.data(), rxData.data()) == 0) && (rxData[0] <= 140)) {
knownLength = true;
} else {
break;
}
}
}
}
if (txMode == ::TxMode::VariableLength && knownLength) {
if (rsData) delete rsData;
rsData = new RS::ReedSolomon(rxData[0], ::getECCBytesForLength(rxData[0]));
}
if (knownLength) {
int decodedLength = rxData[0];
if (rsData->Decode(encodedData.data() + encodedOffset, rxData.data()) == 0) {
printf("Decoded length = %d\n", decodedLength);
if (txMode == ::TxMode::FixedLength && rxData[0] == 'A') {
printf("[ANSWER] Received sound data successfully!\n");
} else if (txMode == ::TxMode::FixedLength && rxData[0] == 'O') {
printf("[OFFER] Received sound data successfully!\n");
} else {
std::string s((char *) rxData.data(), decodedLength);
printf("Received sound data successfully: '%s'\n", s.c_str());
}
framesToRecord = 0;
isValid = true;
}
}
if (isValid) {
break;
}
--framesLeftToAnalyze;
}
if (isValid == false) {
printf("Failed to capture sound data. Please try again\n");
framesToRecord = -1;
}
receivingData = false;
analyzingData = false;
std::fill(sampleSpectrum.begin(), sampleSpectrum.end(), 0.0f);
framesToAnalyze = 0;
framesLeftToAnalyze = 0;
}
// check if receiving data
if (receivingData == false) {
bool isReceiving = true;
for (int i = 0; i < nBitsInMarker; ++i) {
int bin = std::round(dataFreqs_hz[i]*ihzPerFrame);
if (i%2 == 0) {
if (sampleSpectrum[bin] <= 3.0f*sampleSpectrum[bin + d0]) isReceiving = false;
} else {
if (sampleSpectrum[bin] >= 3.0f*sampleSpectrum[bin + d0]) isReceiving = false;
}
}
if (isReceiving) {
std::time_t timestamp = std::time(nullptr);
printf("%sReceiving sound data ...\n", std::asctime(std::localtime(×tamp)));
rxData.fill(0);
receivingData = true;
if (txMode == ::TxMode::FixedLength) {
recvDuration_frames = nMarkerFrames + nPostMarkerFrames + framesPerTx*((::kDefaultFixedLength + paramECCBytesPerTx)/paramBytesPerTx + 1);
} else {
recvDuration_frames = nMarkerFrames + nPostMarkerFrames + framesPerTx*((::kMaxLength + ::getECCBytesForLength(::kMaxLength))/paramBytesPerTx + 1);
}
framesToRecord = recvDuration_frames;
framesLeftToRecord = recvDuration_frames;
}
} else if (txMode == ::TxMode::VariableLength) {
bool isEnded = true;
for (int i = 0; i < nBitsInMarker; ++i) {
int bin = std::round(dataFreqs_hz[i]*ihzPerFrame);
if (i%2 == 0) {
if (sampleSpectrum[bin] >= 3.0f*sampleSpectrum[bin + d0]) isEnded = false;
} else {
if (sampleSpectrum[bin] <= 3.0f*sampleSpectrum[bin + d0]) isEnded = false;
}
}
if (isEnded && framesToRecord > 1) {
std::time_t timestamp = std::time(nullptr);
printf("%sReceived end marker\n", std::asctime(std::localtime(×tamp)));
recvDuration_frames -= framesLeftToRecord - 1;
framesLeftToRecord = 1;
}
}
} else {
break;
}
++nIterations;
}
auto tCallEnd = std::chrono::high_resolution_clock::now();
tSum_ms += getTime_ms(tCallStart, tCallEnd);
if (++nCalls == 10) {
averageRxTime_ms = tSum_ms/nCalls;
tSum_ms = 0.0f;
nCalls = 0;
}
if ((int) SDL_GetQueuedAudioSize(devid_in) > 32*sampleSizeBytes*samplesPerFrame) {
printf("nIter = %d, Queue size: %d\n", nIterations, SDL_GetQueuedAudioSize(devid_in));
SDL_ClearQueuedAudio(devid_in);
}
}
int nIterations;
bool needUpdate = false;
int paramFreqDelta = 6;
int paramFreqStart = 40;
int paramFramesPerTx = 6;
int paramBytesPerTx = 2;
int paramECCBytesPerTx = 32;
int paramVolume = 10;
// Rx
bool receivingData;
bool analyzingData;
std::array<float, kMaxSamplesPerFrame> fftIn;
std::array<std::complex<float>, kMaxSamplesPerFrame> fftOut;
::AmplitudeData sampleAmplitude;
::SpectrumData sampleSpectrum;
std::array<std::uint8_t, ::kMaxDataSize> rxData;
std::array<std::uint8_t, ::kMaxDataSize> encodedData;
int historyId = 0;
::AmplitudeData sampleAmplitudeAverage;
std::array<::AmplitudeData, ::kMaxSpectrumHistory> sampleAmplitudeHistory;
::RecordedData recordedAmplitude;
// Tx
bool hasData;
int sampleSizeBytes;
float sampleRate;
float sampleRateOut;
int samplesPerFrame;
float isamplesPerFrame;
::AmplitudeData outputBlock;
::AmplitudeData16 outputBlock16;
std::array<::AmplitudeData, ::kMaxDataBits> bit1Amplitude;
std::array<::AmplitudeData, ::kMaxDataBits> bit0Amplitude;
float sendVolume;
float hzPerFrame;
float ihzPerFrame;
int d0 = 1;
float freqStart_hz;
float freqDelta_hz;
int frameId;
int nRampFrames;
int nRampFramesBegin;
int nRampFramesEnd;
int nRampFramesBlend;
int dataId;
int framesPerTx;
int framesToAnalyze;
int framesLeftToAnalyze;
int framesToRecord;
int framesLeftToRecord;
int nBitsInMarker;
int nMarkerFrames;
int nPostMarkerFrames;
int recvDuration_frames;
::TxMode txMode = ::TxMode::FixedLength;
std::array<bool, ::kMaxDataBits> dataBits;
std::array<double, ::kMaxDataBits> phaseOffsets;
std::array<double, ::kMaxDataBits> dataFreqs_hz;
int nDataBitsPerTx;
int nECCBytesPerTx;
int sendDataLength;
RS::ReedSolomon * rsData = nullptr;
RS::ReedSolomon * rsLength = nullptr;
float averageRxTime_ms = 0.0;
std::string textToSend;
};
int init() {
if (g_isInitialized) return 0;
printf("Initializing ...\n");
SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
if (SDL_Init(SDL_INIT_AUDIO) < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
return (1);
}
SDL_SetHintWithPriority(SDL_HINT_AUDIO_RESAMPLING_MODE, "medium", SDL_HINT_OVERRIDE);
{
int nDevices = SDL_GetNumAudioDevices(SDL_FALSE);
printf("Found %d playback devices:\n", nDevices);
for (int i = 0; i < nDevices; i++) {
printf(" - Playback device #%d: '%s'\n", i, SDL_GetAudioDeviceName(i, SDL_FALSE));
}
}
{
int nDevices = SDL_GetNumAudioDevices(SDL_TRUE);
printf("Found %d capture devices:\n", nDevices);
for (int i = 0; i < nDevices; i++) {
printf(" - Capture device #%d: '%s'\n", i, SDL_GetAudioDeviceName(i, SDL_TRUE));
}
}
SDL_AudioSpec desiredSpec;
SDL_zero(desiredSpec);
desiredSpec.freq = ::kBaseSampleRate;
desiredSpec.format = AUDIO_S16SYS;
desiredSpec.channels = 1;
desiredSpec.samples = 16*1024;
desiredSpec.callback = NULL;
SDL_AudioSpec obtainedSpec;
SDL_zero(obtainedSpec);
if (g_playbackId >= 0) {
printf("Attempt to open playback device %d : '%s' ...\n", g_playbackId, SDL_GetAudioDeviceName(g_playbackId, SDL_FALSE));
devid_out = SDL_OpenAudioDevice(SDL_GetAudioDeviceName(g_playbackId, SDL_FALSE), SDL_FALSE, &desiredSpec, &obtainedSpec, 0);
} else {
printf("Attempt to open default playback device ...\n");
devid_out = SDL_OpenAudioDevice(NULL, SDL_FALSE, &desiredSpec, &obtainedSpec, 0);
}
if (!devid_out) {
printf("Couldn't open an audio device for playback: %s!\n", SDL_GetError());
devid_out = 0;
} else {
printf("Obtained spec for output device (SDL Id = %d):\n", devid_out);
printf(" - Sample rate: %d (required: %d)\n", obtainedSpec.freq, desiredSpec.freq);
printf(" - Format: %d (required: %d)\n", obtainedSpec.format, desiredSpec.format);
printf(" - Channels: %d (required: %d)\n", obtainedSpec.channels, desiredSpec.channels);
printf(" - Samples per frame: %d (required: %d)\n", obtainedSpec.samples, desiredSpec.samples);
if (obtainedSpec.format != desiredSpec.format ||
obtainedSpec.channels != desiredSpec.channels ||
obtainedSpec.samples != desiredSpec.samples) {
SDL_CloseAudio();
throw std::runtime_error("Failed to initialize desired SDL_OpenAudio!");
}
}
SDL_AudioSpec captureSpec;
captureSpec = obtainedSpec;
captureSpec.freq = ::kBaseSampleRate;
captureSpec.format = AUDIO_F32SYS;
captureSpec.samples = 1024;
if (g_playbackId >= 0) {
printf("Attempt to open capture device %d : '%s' ...\n", g_captureId, SDL_GetAudioDeviceName(g_captureId, SDL_FALSE));
devid_in = SDL_OpenAudioDevice(SDL_GetAudioDeviceName(g_captureId, SDL_TRUE), SDL_TRUE, &captureSpec, &captureSpec, 0);
} else {
printf("Attempt to open default capture device ...\n");
devid_in = SDL_OpenAudioDevice(g_captureDeviceName, SDL_TRUE, &captureSpec, &captureSpec, 0);
}
if (!devid_in) {
printf("Couldn't open an audio device for capture: %s!\n", SDL_GetError());
devid_in = 0;
} else {
printf("Obtained spec for input device (SDL Id = %d):\n", devid_in);
printf(" - Sample rate: %d\n", captureSpec.freq);
printf(" - Format: %d (required: %d)\n", captureSpec.format, desiredSpec.format);
printf(" - Channels: %d (required: %d)\n", captureSpec.channels, desiredSpec.channels);
printf(" - Samples per frame: %d\n", captureSpec.samples);
}
int sampleSizeBytes = 4;
//switch (obtainedSpec.format) {
// case AUDIO_U8:
// case AUDIO_S8:
// sampleSizeBytes = 1;
// break;
// case AUDIO_U16SYS:
// case AUDIO_S16SYS:
// sampleSizeBytes = 2;
// break;
// case AUDIO_S32SYS:
// case AUDIO_F32SYS:
// sampleSizeBytes = 4;
// break;
//}
g_data = new DataRxTx(obtainedSpec.freq, ::kBaseSampleRate, captureSpec.samples, sampleSizeBytes, "");
g_isInitialized = true;
return 0;
}
// JS interface
extern "C" {
int setText(int textLength, const char * text) {
g_data->init(textLength, text);
return 0;
}
int getText(char * text) {
std::copy(g_data->rxData.begin(), g_data->rxData.end(), text);
return 0;
}
int getSampleRate() { return g_data->sampleRate; }
float getAverageRxTime_ms() { return g_data->averageRxTime_ms; }
int getFramesToRecord() { return g_data->framesToRecord; }
int getFramesLeftToRecord() { return g_data->framesLeftToRecord; }
int getFramesToAnalyze() { return g_data->framesToAnalyze; }
int getFramesLeftToAnalyze() { return g_data->framesLeftToAnalyze; }
int hasDeviceOutput() { return devid_out; }
int hasDeviceCapture() { return (g_totalBytesCaptured > 0) ? devid_in : 0; }
int doInit() { return init(); }
int setTxMode(int txMode) { g_data->txMode = (::TxMode)(txMode); return 0; }
void setParameters(
int paramFreqDelta,
int paramFreqStart,
int paramFramesPerTx,
int paramBytesPerTx,
int /*paramECCBytesPerTx*/,
int paramVolume) {
if (g_data == nullptr) return;
g_data->paramFreqDelta = paramFreqDelta;
g_data->paramFreqStart = paramFreqStart;
g_data->paramFramesPerTx = paramFramesPerTx;
g_data->paramBytesPerTx = paramBytesPerTx;
g_data->paramVolume = paramVolume;
g_data->needUpdate = true;
}
}
// main loop
void update() {
if (g_isInitialized == false) return;
SDL_Event e;
SDL_bool shouldTerminate = SDL_FALSE;
while (SDL_PollEvent(&e)) {
if (e.type == SDL_QUIT) {
shouldTerminate = SDL_TRUE;
}
}
if (g_data->hasData == false) {
SDL_PauseAudioDevice(devid_out, SDL_FALSE);
static auto tLastNoData = std::chrono::high_resolution_clock::now();
auto tNow = std::chrono::high_resolution_clock::now();
if ((int) SDL_GetQueuedAudioSize(devid_out) < g_data->samplesPerFrame*g_data->sampleSizeBytes) {
SDL_PauseAudioDevice(devid_in, SDL_FALSE);
if (::getTime_ms(tLastNoData, tNow) > 500.0f) {
g_data->receive();
} else {
SDL_ClearQueuedAudio(devid_in);
}
} else {
tLastNoData = tNow;
//SDL_ClearQueuedAudio(devid_in);
//SDL_Delay(10);
}
} else {
SDL_PauseAudioDevice(devid_out, SDL_TRUE);
SDL_PauseAudioDevice(devid_in, SDL_TRUE);
g_data->send();
}
if (shouldTerminate) {
SDL_PauseAudioDevice(devid_in, 1);
SDL_CloseAudioDevice(devid_in);
SDL_PauseAudioDevice(devid_out, 1);
SDL_CloseAudioDevice(devid_out);
SDL_CloseAudio();
SDL_Quit();
#ifdef __EMSCRIPTEN__
emscripten_cancel_main_loop();
#endif
}
}
static std::map<std::string, std::string> parseCmdArguments(int argc, char ** argv) {
int last = argc;
std::map<std::string, std::string> res;
for (int i = 1; i < last; ++i) {
if (argv[i][0] == '-') {
if (strlen(argv[i]) > 1) {
res[std::string(1, argv[i][1])] = strlen(argv[i]) > 2 ? argv[i] + 2 : "";
}
}
}
return res;
}
int main(int argc, char** argv) {
#ifdef __EMSCRIPTEN__
printf("Build time: %s\n", BUILD_TIMESTAMP);
printf("Press the Init button to start\n");
g_captureDeviceName = argv[1];
#else
printf("Usage: %s [-cN] [-pN] [-tN]\n", argv[0]);