openwebrx-clone/csdr/chain/fft.py

from csdr.chain import Chain
from pycsdr.modules import Fft, LogPower, LogAveragePower, FftSwap, FftAdpcm


class FftAverager(Chain):
    def __init__(self, fft_size, fft_averages):
        self.fftSize = fft_size
        self.fftAverages = fft_averages
        workers = [self._getWorker()]
        super().__init__(workers)

    def setFftAverages(self, fft_averages):
        if self.fftAverages == fft_averages:
            return
        self.fftAverages = fft_averages
        self.replace(0, self._getWorker())

    def _getWorker(self):
        if self.fftAverages == 0:
            return LogPower(add_db=-70)
        else:
            return LogAveragePower(add_db=-70, fft_size=self.fftSize, avg_number=self.fftAverages)


class FftChain(Chain):
    def __init__(self, samp_rate, fft_size, fft_v_overlap_factor, fft_fps, fft_compression):
        self.sampleRate = samp_rate
        self.vOverlapFactor = fft_v_overlap_factor
        self.fps = fft_fps
        self.size = fft_size

        self.blockSize = 0

        self.fft = Fft(size=self.size, every_n_samples=self.blockSize)
        self.averager = FftAverager(fft_size=self.size, fft_averages=10)
        self.fftExchangeSides = FftSwap(fft_size=self.size)
        workers = [
            self.fft,
            self.averager,
            self.fftExchangeSides,
        ]
        self.compressFftAdpcm = None
        if fft_compression == "adpcm":
            self.compressFftAdpcm = FftAdpcm(fft_size=self.size)
            workers += [self.compressFftAdpcm]

        self._updateParameters()

        super().__init__(workers)

    def _setBlockSize(self, fft_block_size):
        if self.blockSize == int(fft_block_size):
            return
        self.blockSize = int(fft_block_size)
        self.fft.setEveryNSamples(self.blockSize)

    def setVOverlapFactor(self, fft_v_overlap_factor):
        if self.vOverlapFactor == fft_v_overlap_factor:
            return
        self.vOverlapFactor = fft_v_overlap_factor
        self._updateParameters()

    def setFps(self, fft_fps):
        if self.fps == fft_fps:
            return
        self.fps = fft_fps
        self._updateParameters()

    def setSampleRate(self, samp_rate):
        if self.sampleRate == samp_rate:
            return
        self.sampleRate = samp_rate
        self._updateParameters()

    def _updateParameters(self):
        fftAverages = 0

        if self.vOverlapFactor > 0:
            fftAverages = int(round(1.0 * self.sampleRate / self.size / self.fps / (1.0 - self.vOverlapFactor)))
        self.averager.setFftAverages(fftAverages)

        if fftAverages == 0:
            self._setBlockSize(self.sampleRate / self.fps)
        else:
            self._setBlockSize(self.sampleRate / self.fps / fftAverages)