fltman/claude-code-demo-creator/elevenlabs-dialogue

ElevenLabs Dialogue

Turn a list of lines (each with a voice_id) into spoken audio using ElevenLabs' Text-to-Dialogue API — which produces more natural, expressive delivery than the plain /v1/text-to-speech endpoint, even for single-voice narration.

When to use

• Voice-over for a demo video (one mp3 per shot, timed to each slide).
• Multi-voice dialogue (podcasts, scenes) — each line carries its own voice.
• Any narration where you want a per-line, content-addressed cache so re-runs are

free for unchanged lines.

Prerequisites

pip install elevenlabs pydub        # pydub optional (cleaner concat); ffmpeg used otherwise
export ELEVENLABS_API_KEY=...        # never hardcode this in a committed file

The key lives in your environment. Find a cloned voice id with:

curl -s -H "xi-api-key: $ELEVENLABS_API_KEY" https://api.elevenlabs.io/v1/voices \
  | python3 -c 'import sys,json;[print(v["voice_id"],v["name"],v.get("category")) for v in json.load(sys.stdin)["voices"]]'

Generate

Input is a JSON array of { "text", "voice_id" } items. Keep [emotion] delivery tags (e.g. [warm], [calm]) inline — they're English even for other languages.

# one mp3 for the whole array:
python3 scripts/generate_dialogue.py --input lines.json --output out.mp3
 
# for a demo video, generate ONE file per shot so each slide is timed to its clip:
python3 scripts/generate_dialogue.py --input shot-01.json --output audio/01.mp3

lines.json:

[
  { "text": "[warm] Welcome — here's how it works.", "voice_id": "VOICE_ID" }
]

Useful flags: --list-chunks (print the chunking plan, no API calls), --regen 3,7 (force-regenerate specific chunks), --force (drop the whole cache), --no-concat (chunks only). The per-chunk cache lives in <output_dir>/.segments/<basename>/ — identical chunks are reused across runs, so you're never billed twice for the same line.

Verify (optional, recommended)

verify_dialogue.py transcribes each generated chunk back with whisper.cpp and flags TTS glitches — stuck loops, skipped/over-long output, dead air — so you catch a bad take before assembling the video.

WHISPER_CLI=~/whisper.cpp/build/bin/whisper-cli \
WHISPER_MODEL=~/whisper.cpp/models/ggml-base.bin \
WHISPER_LANG=en \
python3 scripts/verify_dialogue.py --cache-dir audio/.segments/01 --save-transcripts

For Swedish narration, point WHISPER_MODEL at a KB-Whisper ggml model and set WHISPER_LANG=sv for the most accurate check. Verification is optional — skip it if you don't have whisper.cpp installed.

Disclosure

If you narrate with someone's cloned voice, the honest default is to say so (e.g. open with a short "this is an AI using my cloned voice"). Use a clone only with that person's consent.