$ cat ~/blog/depoaudio-court-audio.md
DepoAudio: getting court audio out of jail
Why I built a free, open-source desktop app that converts proprietary court recording formats — and why it never touches the cloud.
If you work anywhere near litigation, you’ve lived this one: someone hands you a disc — yes, a disc — of courtroom audio, and the files won’t open in anything. .sgmca. FTR. Multi-channel BWF with a sidecar you’re apparently supposed to know about. The hearing happened, the record exists, and you still can’t listen to it without tracking down a proprietary player from a vendor who really wants to sell your firm a license.
I work at a court reporting firm. We produce the record. Watching the record get held hostage by file formats finally annoyed me enough to do something about it.
the rules I set
Legal audio is confidential by default, so the design constraints wrote themselves:
- Everything happens on your machine. No uploads, no processing service, no “we take security seriously” page. The audio never leaves your computer because there’s nowhere for it to go.
- No accounts. You shouldn’t have to create a login to listen to a hearing you were at.
- Free, permanently. This is plumbing. Plumbing shouldn’t have a subscription.
what it does
DepoAudio converts SGMCA, FTR, BWF and friends into formats the rest of the world actually plays — WAV, MP3, FLAC, Opus. It’ll clean up and merge recordings, and it keeps a local library organized the way legal work is actually organized: by case and participant, not by AUDIO_0047_FINAL(2).zip.
the stack
Tauri 2 with a Rust backend and a React front end. Rust handles format detection, builds the FFmpeg filter chains, and persists the library; Tauri keeps the whole thing small and native instead of shipping a browser in a trench coat. GitHub Actions builds signed Windows and macOS installers on every version tag.
why open source
Because “trust me” is not a security model you should accept from legal software. The whole thing is on GitHub — auditable, forkable, yours to keep. If your IT department wants to read every line before it touches a deposition, they can. Honestly, they should.
$ depoaudio --input hearing_0312.sgmca --to flac
✓ converted locally — nothing left this machineRuns on Windows 10+ and macOS 12+. If there’s a format you’re stuck with that it doesn’t handle yet, the repo takes format requests — that’s half the roadmap.
— Andrew