Quote from: TF3RDL on 2024-05-19 22:55:49

Also, I think this topic is little bit de-railed; it went into performance improvements of multichannel audio spectrum analyzers by using complex-input FFTs, which is true considering calculating two or more FFTs can have significant performance impact. But what I really mean is that is complex-input FFT as in spectrum of I/Q signals in SDR really useful for analysis of stereo audio, which is basically the same minus the "unscrambling" operation?

I don't see any reason you would want the scrambled output when you could have the regular unscrambled one instead. 

Also, I think this topic is little bit de-railed; it went into performance improvements of multichannel audio spectrum analyzers by using complex-input FFTs, which is true considering calculating two or more FFTs can have significant performance impact. But what I really mean is that is complex-input FFT as in spectrum of I/Q signals in SDR really useful for analysis of stereo audio, which is basically the same minus the "unscrambling" operation?

Anyone else see large random negative offsets being put in sycnched lyric files with V0.6. I think it happened with previous versions too.  If I remove the large offset, can be somewhere around -78000, then the lyrics are prefectly synched.  So it seems to be put in in error.  It seems to happen comtinuously for a while, then it goes back to working fine.  Lyric sources are from MusixMatch or Deezer. 

Getting blank Clip count in my playlist with this new version. Before it said 0, now it's just blank. Using this string:

%truepeak_scanner_clipped_samples_track%

The albums I have included here are: Taylor Swift: the tortured poet department and Emmanuel Pahud, Éric le Sage: Mozart stories

As for the feature request of letting you visualize all channels as FFTs of each channel, I meant this: (BTW, I've updated this interactive mockup to add this, which already exists on the similar spectrum analyzer plugin for another music player except for the M/S part)
[attach type=image]26984[/attach]
And for Mid/Side part (which can be easily done using M/S encoding then doing FFTs of resulting M/S signal for visualization):
[attach type=image]26986[/attach]

Since the real and imaginary parts of the transform are orthogonal, this is the same as performing a real-valued FFT once for each input and then combining the individual outputs. 

See this derivation for a more detailed explanation:  http://www.hyperdynelabs.com/dspdude/papers/COMPUTING%20THE%20FFT%20OF%20TWO%20REAL%20SIGNALS%20USING%20A%20SINGLE%20FFT.pdf

const j = complexSpectrum.length-i;
      x = idxWrapOver(i, complexSpectrum.length),
      y = idxWrapOver(j, complexSpectrum.length);
spectrum1[i] = Math.hypot(complexSpectrum[x].re+complexSpectrum[y].re, complexSpectrum[x].im-complexSpectrum[y].im)/Math.SQRT2;
spectrum2[i] = Math.hypot(complexSpectrum[x].im+complexSpectrum[y].im, complexSpectrum[x].re-complexSpectrum[y].re)/Math.SQRT2;

function idxWrapOver(x, length) {
  return (x % length + length) % length;
}