Module cqt_bake 

Constant-Q transform sidecar bake — log-spaced bins for timbral integrity (cold path).

Functions

bake_cqt_sidecar_from_preview

Bake CQT sidecar into caller buffer (_pad = SIDECAR_KIND_CQT).

bake_cqt_sidecar_from_samples

Bake a CQT sidecar from REAL audio samples: compute the genuine forward CQT, reduce n_bins → SPECTRAL_PREVIEW_BINS, and write a single-frame sidecar through the same header machinery as bake_cqt_sidecar_from_preview (_pad = SIDECAR_KIND_CQT). When n_bins == SPECTRAL_PREVIEW_BINS the magnitudes are used directly.

forward_cqt

Real forward constant-Q transform over actual audio samples — direct constant-Q (one complex inner product per log-spaced bin; CPU is fine, this is a cold-path ingest transform).

preview_to_cqt_frame

Map linear preview energy into log-spaced CQT bins (MIDI-ish spacing across 64 bins).