knock_spectrogram.cpp

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/**
 * @file    knock_spectrogram.cpp
 *
 * @date Feb 20, 2024
 * @author Alexey Ershov, (c) 2023-2024
 */
 
#include "pch.h"
 
#ifdef KNOCK_SPECTROGRAM
 
#include "knock_spectrogram.h"
#include <climits>
 
#if EFI_TEXT_LOGGING
static char PROTOCOL_KNOCK_SPECTROGRAMM_BUFFER[128] CCM_OPTIONAL;
static Logging scLogging("knock_spectrogram", PROTOCOL_KNOCK_SPECTROGRAMM_BUFFER, sizeof(PROTOCOL_KNOCK_SPECTROGRAMM_BUFFER));
 
static char compressToByte(const float& v, const float& min, const float& max) {
    float vn = (v-min) / (max-min);
    int iv =int((float)256 * vn);
 
    char compressed = (char)(iv-128);
    return compressed;
}
 
void base64(Logging& l, const float* data, size_t size, const float& min, const float& max) {
    static constexpr char encTable[] = {
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
        'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
        'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
 
    size_t in_len = size;
    size_t out_len = 4 * ((in_len + 2) / 3);
    size_t i;
 
    l.appendChar((char)out_len);
 
    for (i = 0; in_len > 2 && i < in_len - 2; i += 3) {
        l.appendChar(encTable[(compressToByte(data[i], min, max) >> 2) & 0x3F]);
        l.appendChar(encTable[((compressToByte(data[i], min, max) & 0x3) << 4) |
                            ((int)(compressToByte(data[i + 1], min, max) & 0xF0) >> 4)]);
        l.appendChar(encTable[((compressToByte(data[i + 1], min, max) & 0xF) << 2) |
                            ((int)(compressToByte(data[i + 2], min, max) & 0xC0) >> 6)]);
        l.appendChar(encTable[compressToByte(data[i + 2], min, max) & 0x3F]);
    }
    if (i < in_len) {
        l.appendChar(encTable[(compressToByte(data[i], min, max) >> 2) & 0x3F]);
 
        if (i == (in_len - 1)) {
            l.appendChar(encTable[((compressToByte(data[i], min, max) & 0x3) << 4)]);
            l.appendChar('=');
        } else {
            l.appendChar(encTable[((compressToByte(data[i], min, max) & 0x3) << 4) |
                                ((int)(compressToByte(data[i + 1], min, max) & 0xF0) >> 4)]);
            l.appendChar(encTable[((compressToByte(data[i + 1], min, max) & 0xF) << 2)]);
        }
 
        l.appendChar('=');
    }
}
#endif /* EFI_TEXT_LOGGING */
 
void knockSpectorgramAddLine(float main_freq, float* data, size_t size) {
#if EFI_TEXT_LOGGING
    if (scLogging.remainingSize() > size) {
 
        float min = 99999999999;
        float max = -99999999999;
        for(size_t i = 0; i < size; ++i) {
            float v = data[i];
            if(v < min) {
                min = v;
            }
 
            if(v > max) {
                max = v;
            }
        }
 
        scLogging.reset();
        scLogging.appendPrintf(PROTOCOL_KNOCK_SPECTROGRAMM LOG_DELIMITER);
 
        scLogging.appendFloat(main_freq, 2);
        scLogging.appendPrintf("*");
 
        scLogging.appendChar((char)size);
 
        base64(scLogging, data, size, min, max);
 
        scLogging.append(LOG_DELIMITER);
 
        scheduleLogging(&scLogging);
    }
 
#endif /* EFI_TEXT_LOGGING */
}
 
#endif /* KNOCK_SPECTROGRAM */