Created by Niche-Knack

Useful work should
be useful again.

CBFP grew out of a practical question: why should every device have to analyze the same recording from scratch?

Why we made it

Niche-Knack Apps LLC develops focused tools for everyday problems. We created CBFP for Choirboy, which lets people choose what gets filtered in media they own or legitimately access.

Speech analysis can demand more computing power than playback. A reusable filtering record can carry the results to another compatible device, while leaving the original media intact and the listener’s preferences in their own hands.

A matching, complete record can save a device from another speech-recognition pass. That depends on establishing the recording, its timing and coverage; it does not make every edition interchangeable or remove the need to check a result.

More than a file extension

The specification describes the pieces that travel together: recording identity, timed filtering spans, associated words and separate edits. An acoustic identity helps answer “which recording?” Filtering spans answer “which moments?” A player still decides how to apply the listener’s choices.

Documenting those boundaries gives implementers something concrete to review and test. CBFP is a media fingerprint format. It does not describe biometric fingerprints, transfer ownership of a recording or grant access to someone else’s media.

Working toward an open specification

The specification and SDK are currently review drafts. The intended next step is an openly licensed specification and developer tooling; the exact licenses have not yet been selected. This preview does not grant an open-source or Creative Commons license.

The SDK remains a private prototype. Its future release, the specification’s license and the resolution of existing reader differences are separate decisions. Read the draft’s compatibility status before treating it as an implementation contract.

Help make the contract clearer

Send questions about the format, unclear examples or interoperability needs to support@nk.tools. For Choirboy setup and use, visit the Choirboy support guides.

Site analytics

We use Niche-Knack’s Umami service to count visits and downloads of the schemas and examples. The tracker respects Do Not Track and removes URL queries, fragments and detailed referrer paths before sending an event. Download events include only a fixed file label. Local review previews do not send visit events.

Questions sent by email are support correspondence, separate from site analytics. See Niche-Knack’s privacy information for contact details and support-data handling.