Ask HN: Fable hacked my piano, can I release the results?
- ID
- 22099
- Status
- summarized
- Published
- 05 Sep 2026, 10:54 PM
- Fetched
- 07 Sep 2026, 10:55 PM
- Provider
- Hacker News
- Category
- dev-community
- Original URL
- https://news.ycombinator.com/item?id=49577129
- Source URL
- https://hnrss.org/best
Summary
- Score
- 7.0
- Created
- 08 Sep 2026, 12:04 AM
- Tags
- Audience
- developersvibe_codersai_agent_users
What happened
A Hacker News user used AI agents (Astra and Fable) to reverse-engineer PianoDisc Prodigy's proprietary MP3-MIDI format, which encodes MIDI data in the right audio channel via a 2004.5 Hz square wave. Fable discovered PianoDisc inserts 'decoy notes' as obfuscation that makes naively extracted MIDI unplayable on other systems, then built both an encoder and decoder that handles the decoy notes. The user is now asking whether publishing the decoder or encoder would be legal.
Why it matters
This is a concrete example of AI agents autonomously reverse-engineering a proprietary format—including discovering undocumented anti-interoperability measures—in about an hour of iterative prompting. If you build proprietary file formats or obfuscation, assume AI-assisted reverse engineering dramatically lowers the cost of breaking them; if you ship tools that consume locked formats, expect community decoders to appear faster.
Discussion angle
The legal tension between publishing interoperability code and DMCA anti-circumvention provisions—plus whether AI agents doing the reverse-engineering changes the legal or ethical calculus at all.