paramsen / noise Goto Github PK

package com.paramsen.noise
import kotlin.math.log10

class SoundSpectrumUtils {

    companion object {
        private const val bands = 11
        private val lbands: Array<Int> = arrayOf(11, 22, 44, 88, 177, 355, 710, 1420, 2840, 5680, 11360);
        private val ubands = arrayOf(22, 44, 88, 177, 355, 710, 1420, 2840, 5680, 11360, 22050);
        private val bandSizes = IntArray(bands) { i -> ubands[i] - lbands[i] }

        @JvmStatic
        fun calculateBands(samples: FloatArray): FloatArray {
            val noise = Noise.real(samples.size)

            // not sure why this is, but it's in the sample app, see also https://github.com/paramsen/noise/issues/6
            for (i in samples.indices) {
                samples[i] *= 2.0f
            }

            val fft = noise.fft(samples, FloatArray(samples.size + 2))
            val resultFFT = FloatArray(samples.size);
            System.arraycopy(fft, 2, resultFFT, 0, fft.size - 2)

            val resultBands = FloatArray(bands);
            for (i in 0 until bands) {
                var accum = .0f
                for (j in 0 until bandSizes[i] step 2) {
                    //convert real and imag part to get energy
                    accum += (Math.pow(
                            resultFFT[j + lbands[i]].toDouble(),
                            2.0
                    ) + Math.pow(resultFFT[j + 1 + lbands[i]].toDouble(), 2.0)).toFloat()
                }
                accum /= bandSizes[i] / 2
                accum = 10 * log10(accum)
                resultBands[i] = accum;
            }
            return resultBands;
        }
    }
}

CMake Error at CMakeLists.txt:3 (add_library):
  Cannot find source file:

    src/main/native/kissfft/kiss_fft.c

  Tried extensions .c .C .c++ .cc .cpp .cxx .m .M .mm .h .hh .h++ .hm .hpp
  .hxx .in .txx