Imported from joelhooks/joelclaw (
skills/media-transcription/SKILL.md). Install upstream withnpx skills add joelhooks/joelclaw --skill media-transcription. Copyright stays with the author.
Media Transcription
Durable, event-driven transcription of raw meeting media on the NAS. Inngest
orchestrates; MLX Whisper (chunked ASR) and pyannote (whole-file diarization)
run as detached local actor processes — no Inngest step ever holds a
request open across inference. Built 2026-07-11 after the v1 monolith died to
request-bound 2h timeouts and Whisper hallucination loops (design receipt:
.brain/projects/transcription-pipeline-v2-2026-07-11.svx).
Where it runs (hard constraints)
- Flagg host worker only (
hostFunctionDefinitions, launchdcom.joel.system-bus-worker). Needs the direct NFS mount/Volumes/badass-mediaand the rig checkout. - Local inference implementation:
~/Code/joelhooks/transcript-rig(public repojoelhooks/transcript-rig; override path withTRANSCRIPT_RIG_ROOT). Raw media on the NAS is immutable — the pipeline only writes derived artifacts. - From any other fleet machine: send the event (Inngest routes it to flagg's worker) or SSH to flagg to inspect on-disk state.
Start a transcription
joelclaw send media/transcription.requested -d '{
"requestId": "req-'$(uuidgen | tr 'A-Z' 'a-z')'",
"sourcePath": "/Volumes/badass-media/joel/meetings/<meeting-dir>"
}'
requestIdis the idempotency key — always mint a fresh one; a reused id is silently deduped. Optional flags:"publish": false,"index": false(both default true).sourcePathmust be under/Volumes/badass-media/or the run fails NonRetriable.
Monitor
joelclaw event <event-id>→ run id;joelclaw run <run-id>for step trace. Orchestrator steps keepNN-prefixes for the pijob-monitorwidget (packages/pi-extensions/inngest-monitor).- Progress events:
media/transcription.chunk.completed(per chunk, with index/total/cached), terminalmedia/transcription.completedor.failed. - On-disk truth (flagg):
<rig>/.transcript-rig-work/<artifactId>/orchestration/plan.v1.json— chunk plan (requestId, tracks, chunk ids)orchestration/actors/<chunkId>/status.v1.json— actor heartbeat/stateorchestration/actors/<chunkId>/actor.log— inference stdout/stderrstate.v1.json— rig stage (staged → transcribed → … → complete)editorial/transcript.{md,txt,srt,vtt,tsv}— final outputs
- Published result:
<sourcePath>/derived/transcripts/current.v1.jsonpointer + artifact directory.
Cancel
joelclaw send media/transcription.cancelled -d '{"requestId": "<the-request-id>"}'
Cancels all runs (cancelOn) AND triggers transcription-cleanup-v1, which
SIGTERM→10s→SIGKILLs live actor process groups (identity-verified via ps —
PID reuse safe) and writes orchestration/cancelled.v1.json, which blocks
new actor spawns. Optionally include artifactId to skip the plan scan.
Resume / re-drive
Re-send media/transcription.requested with a fresh requestId and the
same sourcePath. Everything valid on disk is adopted, nothing recomputes:
- Whole-track
raw/asr/<sourceId>/asr.jsonpassing the repetition screen ⇒ track done. A repetitive one is quarantined (.rejected-<ts>) and the track re-chunks. - Existing chunk WAV layouts (
raw/chunked/<sourceId>/chunks/NNN.wav) are adopted; offsets recomputed from ffprobe. Valid chunkout/<i>/asr.json⇒ cached, no actor spawned. - Diarization
raw/diarization/<sourceId>.jsonl(first line parses) ⇒ cached. - Remove
orchestration/cancelled.v1.jsonfirst if the artifact was previously cancelled.
Failure modes (typed, in actor status / run errors)
| Error | Meaning | Action |
|---|---|---|
repetitive_output: … |
Whisper hallucination loop survived collapse (decode mostly padding) | Retries respawn actors; deterministic loops usually pass after collapse-then-screen. Inspect the chunk WAV — genuinely silent/broken audio fails honestly |
inference_required: … |
A fast rig stage (resume --no-inference) found a missing claim check |
Inference didn't complete/adopt; check chunk statuses |
cancelled_by_signal |
Actor's child died to un-initiated SIGTERM/SIGKILL (group kill, operator, or Bun's in-process signal-dispatch race) | Expected during cancel/reap; standalone occurrences mean someone killed processes manually |
actor stalled |
Heartbeat stale >3m | Watchdog killed + retried automatically |
chunk_result_missing |
Aggregation found no valid chunk output | Chunk failed all retries; see its actor.log |
mount_unavailable |
NFS mount down | media/transcription.blocked emitted; remount and re-drive |
Design invariants (don't regress these)
- ASR outputs are parsed with
parseAsrJson(mlx_whisper emits bareNaN). - Repetition screening is collapse-then-screen (
screenWithCollapse): consecutive-duplicate segments collapse to one; >50% collapsed ⇒ failed decode. Aggregation persists the collapsed form. - ASR actors run
--condition-on-previous-text False --hallucination-silence-threshold 2; diarization uses MPS (TRANSCRIPT_RIG_DIARIZE_DEVICE=cputo opt out). waitForEventresults are verified in code against the spawned actorId — the dev-mode Inngest server leaks foreign events past match expressions.- Known dev-server gap: concurrency keys (
transcription-gpulimit 1) are not enforced; expect parallel whispers until the Inngest server is upgraded.
Code: packages/system-bus/src/transcription/ +
packages/system-bus/src/inngest/functions/{media-transcription-pipeline,transcription-asr-chunk,transcription-diarize,transcription-cleanup}.ts.