Transcribe Media

What this skill does

# Transcribe Media

Create a research-grade transcript sidecar for a local acquired audio or video file. This primitive supports media-curator to research handoff. It does not claim transcription support unless an actual local STT tool, approved service adapter, human transcript, or diarization sidecar is available.

## Inputs

Required:
- Local acquired media path.

Optional:
- Source URL, title, creator, acquired-at timestamp, acquisition ID, language.
- Existing transcript or diarization sidecar.

## Output

Write transcript sidecars under `.aiwg/media/transcripts/` or beside the acquired media when the collection already stores sidecars locally.

Recommended filename: `<media-basename>.transcript.json`

Required fields:
- `schema`: `aiwg.media.transcript.v1`
- `source.path`, `source.url`, `source.sha256`
- `transcript.sha256`, `transcript.language`, `transcript.generated_at`, `transcript.tool`, `transcript.quality`
- `segments[]` with stable `id`, `start`, `end`, `text`, and optional `speaker`
- `provenance.wasDerivedFrom`, `provenance.generatedEntity`, `provenance.activity`, `provenance.used`

Segment IDs MUST be stable. Use zero-padded sequential IDs such as `seg-000001` unless the upstream transcript already has durable IDs.

## Hashing

- `source.sha256` is the SHA-256 of the exact local media file bytes.
- `transcript.sha256` is the SHA-256 of the canonical transcript payload used for citation, not the pretty-printed JSON file.
- The canonical payload is the UTF-8 join of `id`, `start`, `end`, `speaker` if present, and `text` for every segment, separated by tabs and newlines.
- Use the same lowercase `sha256:<hex>` convention as media-curator integrity manifests.

## Speaker Labels

Preserve speaker labels when STT output, a diarization sidecar, or a human transcript provides them. If no diarization is available, emit the documented single-speaker fallback `SPEAKER_00` and record the limitation in `transcript.quality.limitations`.

Do not invent speaker names. Replace `SPEAKER_00` with real names only when metadata or human verification proves them.

## Tooling Detection

Check for an available transcription path before generating text:

```bash
command -v whisper-cpp || command -v whisper || command -v vosk-transcriber || true
command -v ffmpeg || true
```

If no STT tool or approved transcript source is available, do not fabricate transcript text. Write or report an actionable plan with:
- `schema`: `aiwg.media.transcript-plan.v1`
- `status`: `blocked-tooling-missing`
- source path and source hash when the media file can be read
- next steps for installing local STT tooling or providing a human transcript
- quality limits stating that no transcript hash exists until segment text exists

## Verification Limits

A generated transcript is evidence of tool output, not proof of exact speech content. Handoff notes MUST state:
- Machine transcripts can contain word errors, omissions, and hallucinated punctuation.
- Speaker labels are provisional unless diarization or human review supports them.
- Research induction should cite the transcript hash and source media hash together.
- Human verification is required before using quotations in high-stakes or published claims.

## Research Handoff

Include the transcript sidecar path, source media hash, transcript hash, source URL, acquisition metadata, quality status, and known limitations.

## Fixture Example

See `examples/sample.transcript.json` for a minimal transcript sidecar with timestamps, speaker fallback, source URL, source hash, transcript hash, and provenance fields.

## References

- @$AIWG_ROOT/agentic/code/frameworks/media-curator/skills/integrity-verification/SKILL.md — SHA-256 manifest and fixity conventions
- @$AIWG_ROOT/agentic/code/frameworks/media-curator/skills/provenance-tracking/SKILL.md — W3C PROV-O derivation model for media artifacts
- @$AIWG_ROOT/docs/integrations/media-curator-to-research-handoff.md — Research handoff expectations for media-derived artifacts