Peaking-EQ filter entries (unwrapped), one ffmpeg equalizer (two-pole
peaking) per band with a non-zero gain, e.g.
equalizer=f=31:width_type=o:width=1:g=5. Returns an empty vec when the EQ
is disabled or every gain is ~0. Gains are assumed already normalised by
AudioSettings::with_equalizer_normalised; bands beyond EQ_BANDS are
ignored.
The loudness-normalization filter entry (unwrapped), or None when
normalization is disabled. Uses ffmpegβs dynaudnorm, a gentle real-time
dynamic normalizer that avoids the gain βpumpingβ loudnormβs single-pass
mode can produce on very dynamic material.