The translation pipeline converts the journal's English caption SRTs (captions/*.srt) into the 11 target languages, writing one SRT per language per item into translations/ (see JOURNAL_SCHEMA.md).

Both engines preserve SRT index, timing lines, and CRLF line endings, and keep brand/proper nouns verbatim (e.g. Active Inference Institute, pymdp, YouTube).

The local-Ollama engine (translate_subtitles.py) was removed on 2026-08-23; the hosted OpenRouter engine is now the only supported translator.

Fast batch translator for large corpora. Two speedups over the local path: (1) many subtitle cues are translated per HTTP request (batching), and (2) requests run concurrently against a hosted API instead of a serialized local GPU.

export OPENROUTER_API_KEY=sk-or-v1-...
python3 scripts/translate_subtitles_openrouter.py --journal ../ActiveInferenceJournal   # all series
python3 scripts/translate_subtitles_openrouter.py --journal ../ActiveInferenceJournal --series GuestStream
python3 scripts/translate_subtitles_openrouter.py --journal ../ActiveInferenceJournal --lang es --lang fr
python3 scripts/translate_subtitles_openrouter.py --journal ../ActiveInferenceJournal --force

Tuning flags:

Environment: OPENROUTER_API_KEY (required — export it, or set it in the repo's gitignored .env), OPENROUTER_BASE_URL (default https://openrouter.ai/api/v1).

Robustness: per-request retry with exponential backoff, and a failed/truncated large batch is recursively split in half down to single cues (so long multi-line cues translate instead of falling back to English).

Placeholder safety: caption files whose exact bytes appear under several different item folders (copied placeholders) are detected via a content-md5 scan, skipped, and reported — they are never translated.

Both engines share the same contract:

• Deterministic ordering — caption files are enumerated in sorted path order.
• Stable filenames — translations/<title>.<lang>.srt derived from the source caption name (drops .en/.m4a suffixes).
• Skip-existing — an existing <lang>.srt is left untouched unless --force, and output is written atomically per file.
• Resumable — interrupt at any point and re-run the same command; it continues from where translation output was missing (optionally --skip-to).
• Preserves source shape — index + timing + CRLF reproduced verbatim, so the journal JOURNAL_SCHEMA.md translations/ requirement is met.

The translation filename is derived from the source caption filename: