Denoise audio samples with FFT.

A description of the accepted parameters follows.

noise_reduction, nr

Set the noise reduction in dB, allowed range is 0.01 to 97. Default value is 12 dB.

noise_floor, nf

Set the noise floor in dB, allowed range is -80 to -20. Default value is -50 dB.

noise_type, nt

Set the noise type.

It accepts the following values:

white, w

Select white noise.

vinyl, v

Select vinyl noise.

shellac, s

Select shellac noise.

custom, c

Select custom noise, defined in bn option.

Default value is white noise.

band_noise, bn

Set custom band noise profile for every one of 15 bands. Bands are separated by ’ ’ or ’|’.

residual_floor, rf

Set the residual floor in dB, allowed range is -80 to -20. Default value is -38 dB.

track_noise, tn

Enable noise floor tracking. By default is disabled. With this enabled, noise floor is automatically adjusted.

track_residual, tr

Enable residual tracking. By default is disabled.

output_mode, om

Set the output mode.

It accepts the following values:

input, i

Pass input unchanged.

output, o

Pass noise filtered out.

noise, n

Pass only noise.

Default value is output.

adaptivity, ad

Set the adaptivity factor, used how fast to adapt gains adjustments per each frequency bin. Value 0 enables instant adaptation, while higher values react much slower. Allowed range is from 0 to 1. Default value is 0.5.

floor_offset, fo

Set the noise floor offset factor. This option is used to adjust offset applied to measured noise floor. It is only effective when noise floor tracking is enabled. Allowed range is from -2.0 to 2.0. Default value is 1.0.

noise_link, nl

Set the noise link used for multichannel audio.

It accepts the following values:

none

Use unchanged channel’s noise floor.

min

Use measured min noise floor of all channels.

max

Use measured max noise floor of all channels.

average

Use measured average noise floor of all channels.

Default value is min.

band_multiplier, bm

Set the band multiplier factor, used how much to spread bands across frequency bins. Allowed range is from 0.2 to 5. Default value is 1.25.

sample_noise, sn

Toggle capturing and measurement of noise profile from input audio.

It accepts the following values:

start, begin

Start sample noise capture.

stop, end

Stop sample noise capture and measure new noise band profile.

Default value is none.

gain_smooth, gs

Set gain smooth spatial radius, used to smooth gains applied to each frequency bin. Useful to reduce random music noise artefacts. Higher values increases smoothing of gains. Allowed range is from 0 to 50. Default value is 0.