Function guessClock

src/fe-inspect.cc:73–128

* Tries to guess the clock by finding the smallest common interval. * Returns nanoseconds. */

 * Returns nanoseconds.
 */
static nanoseconds_t guessClock(const Fluxmap& fluxmap)
{
    if (manualClockRate != 0.0)
        return manualClockRate * 1000.0;

    auto data = FluxmapReader(fluxmap).guessClock(
        noiseFloorFactor.get(), signalLevelFactor.get());

    std::cout << "\nClock detection histogram:" << std::endl;

    uint32_t max =
        *std::max_element(std::begin(data.buckets), std::end(data.buckets));

    bool skipping = true;
    for (int i = 0; i < 256; i++)
    {
        nanoseconds_t value = data.buckets[i];
        if (value < data.noiseFloor / 2)
        {
            if (!skipping)
                std::cout << "..." << std::endl;
            skipping = true;
        }
        else
        {
            skipping = false;

            int bar = 320 * value / max;
            int fullblocks = bar / 8;

            std::string s;
            for (int j = 0; j < fullblocks; j++)
                s += BLOCK_ELEMENTS[8];
            s += BLOCK_ELEMENTS[bar & 7];

            std::cout << fmt::format(
                "{: 3} {:.2f} {:7} {}", i, (double)i * US_PER_TICK, value, s);
            std::cout << std::endl;
        }
    }

    std::cout << fmt::format("Noise floor:  {}\n", data.noiseFloor);
    std::cout << fmt::format("Signal level: {}\n", data.signalLevel);
    std::cout << fmt::format(
        "Peak start:   {:.2f} us\n", data.peakStart / 1000.0);
    std::cout << fmt::format(
        "Peak end:     {:.2f} us\n", data.peakEnd / 1000.0);
    std::cout << fmt::format("Median:       {:.2f} us\n", data.median / 1000.0);

    /*
     * Okay, the median should now be a good candidate for the (or a) clock.
     * How this maps onto the actual clock rate depends on the encoding.
     */

    return data.median;
}

int mainInspect(int argc, const char* argv[])