foobar2000:Components/showcqt (foo_showcqt)

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Developer(s) Alireza Ayoubi (Wamoc)
Release information
Initial release
Stable release
Preview release
foobar2000 compatibility
Minimum version TBC
Maximum version {{{foobar2000_maximum}}}
UI module(s) Default UI, Columns UI
Additional information
Use Visualization
License Proprietary
Discussion thread {{{discussion_thread}}}
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A closed-source re-implementation of the showcqt filter from FFmpeg, combines spectrum analyzer with spectrogram with variable time/frequency resolution using Brown-Puckette variable-Q transform (complex STFT to constant-Q transform using frequency-domain filter bank) with direct frequency-domain kernels. Compatible with both DUI and CUI.

This component doesn't require FFmpeg to be installed.


The options can be accessed by right clicking the visualizer and selecting Options.


FFT size
Sets the FFT size. Can be set with a non-power of 2 value
Default: 8820 samples (200ms on 44100Hz sample rate)
Use non-power of two FFT
Toggles where it uses non-power of two FFT. It reduces latency on non-power of two FFT sizes at the expense of performance. The parameter timeclamp is tied to FFT size parameter while the actual FFT size is rounded to next power of 2 when disabled
Default: Enabled
Window skew
Sets the asymmetric window function before STFT
Default: 0
Frequency range
Sets the frequency range for spectrum/spectrogram visualization
Default: 20Hz - 20kHz
Number of bands
Sets the number of VQT bands
Default: 1920
Use hypotenuse
Toggles where it uses hypotenuse of real and imaginary FFT coefficients (sqrt(real^2 + imag^2)) instead of sum of abs of real + abs of imag parts (abs(real)+abs(imag)). This will improve accuracy at the expense of small performance drop
Default: Enabled
Channel configuration
Sets the channel configuration for first and second FFT channels. It can be either left/right or a mid/side configuration
Default: Stereo (Left/Right)
Frequency axis
Set the type of frequency axis to display; the default one is based on note frequencies while Logarithmic axis displays Hz frequencies
Default: Musical notes
Transform count
Set the transform count for every update. Higher values makes spectrogram scroll faster
Default: 12
Set the bandwidth for CQT kernels. Setting it too low makes artifacts noticeable. The kernel shape is Nuttall window function
Default: 6x bins wide


Note: this section have two values; one for the spectrum and other for spectrogram

Logarithmic amplitude scale
Toggles where it uses dB instead of nth root or linear amplitude scale
Default: False
Sets the gamma factor for linear/nth root amplitude scale
Default: 1 (for spectrum), 2 (for spectrogram)
dB range
Sets the dB range on a logarithmic amplitude scale
Default: -70dB
Output multipler
Sets the output multipler
Default: 16

External links[edit]