CBFP / Media fingerprint specification
A small file.
A shared
understanding.
Give media analysis a life beyond one device. CBFP describes a recording and its timed filtering decisions, so compatible players can use the work already done.
Created by Niche-Knack. Developed for Choirboy. Documented for review.
One recording. Analysis that can travel.
The work starts with the media.
Keep the media separate.
Share the analysis without bundling the recording.
Reuse work across devices.
A matching fingerprint can avoid another full scan.
Leave room for personal choice.
One recording can carry different filtering timelines.
What is a fingerprint?
The recording stays.
The understanding travels.
A CBFP fingerprint is a small companion to media: it identifies a recording and describes timed filtering information. It can travel between compatible tools while the song, movie or podcast stays with its owner. The format describes data; each player remains responsible for checking the recording, timing and access before using it.
{
"format": "choirboy.sidecar/2",
"sha256": "…recording identity…",
"spans": [{
"word": "example",
"startMs": 1000,
"endMs": 1500,
"action": "mute"
}]
}Know the recording.
Identity distinguishes a specific recording from another file or edition with the same title.
Describe the moment.
Timed spans place filtering decisions at exact positions in the recording.
Keep decisions editable.
Separate edit layers let a listener refine their choices while preserving the underlying analysis.
Why Niche-Knack built it
A capable device can do the work.
Other devices can benefit.
Speech recognition can be demanding. In Choirboy, an eligible fingerprint for the same recording can let a supported device reuse completed analysis and skip that pass. A smaller device can spend its effort on playback and the listener’s preferences.
That depends on a suitable match, complete coverage and usable timing. The format provides a way to describe those results; it does not make every file ready for every player.
Read the story behind CBFP →The next step
Tools to make the format useful.
A first Python SDK exists as a private prototype. It can inspect files, validate MAIN data, encode and decode landmark records, and write a basic bundle. Public release is being prepared.