demo-audio-producer

name	Demo Audio Producer
description	Create Onto2AI product demos and generate AI narration audio files in the demo folder.

Demo Audio Producer Instructions

Use this skill when the user asks to create or update demo walkthrough content, voiceover scripts, or narrated audio files.

Scope

• Maintain demo assets under demo/.
• Keep narration scripts and audio outputs aligned.
• Use AI-generated voice narration for quick review and presentation drafts.

Standard Output Layout

• demo/demo-audio-scripts.md — canonical script source.
• demo/demo_tts_jobs.jsonl — batch TTS job file.
• demo/audio/*.mp3 — generated narration files.
• demo/video/<demo_name>/<demo_name>_demo.json — single source of truth manifest.
• demo/video/review/*.mp4 — rendered review videos.

File Contract (Purpose + When to Use)

• demo/demo-audio-scripts.md Purpose: master script catalog across demos. When to use: define or revise content before generating audio.
• demo/demo_tts_jobs.jsonl Purpose: batch job list for TTS (input, out). When to use: generate many audio clips in one pass.
• demo/audio/<demo>.mp3 Purpose: narration output for one demo. When to use: attach to screen recording or review voice quality.
• demo/video/<demo>/<demo>_demo.json Purpose: canonical per-demo manifest (narrative text + timing + scenes + TTS config). When to use: every edit; avoid parallel duplicate files.
• demo/video/review/*.mp4 Purpose: synced preview/final review outputs. When to use: approval rounds and iteration.

Workflow

1. Draft or update demo/demo-audio-scripts.md.
2. Build/refresh demo/demo_tts_jobs.jsonl from script content (one JSON object per line with input and out).
3. Generate audio into demo/audio/.
4. Verify expected file count and naming.
5. Keep all demo assets in demo/ (do not scatter files in docs/ or output/).

Single Clip Generation

Use when iterating one demo only.

# derive narration from JSON manifest
jq -r '.narrative_lines | sort_by(.start_ms) | .[].text' \
  demo/video/demo01/demo01_demo.json > /tmp/demo01_narration.txt

python /Users/weizhang/.codex/skills/speech/scripts/text_to_speech.py speak \
  --input-file /tmp/demo01_narration.txt \
  --voice cedar \
  --response-format mp3 \
  --instructions "Voice Affect: Warm and composed. Tone: Professional and clear. Pacing: Steady." \
  --out demo/audio/demo01.mp3 \
  --force

Audio Generation Command

Use the speech skill CLI:

python /Users/weizhang/.codex/skills/speech/scripts/text_to_speech.py speak-batch \
  --input demo/demo_tts_jobs.jsonl \
  --out-dir demo/audio \
  --voice cedar \
  --response-format mp3 \
  --instructions "Voice Affect: Warm and composed. Tone: Professional and friendly. Pacing: Steady and clear." \
  --rpm 50 \
  --force

Quality Rules

• Keep each narration clip concise and presentation-ready.
• Use deterministic file names like demo01_*.mp3, demo02_*.mp3, etc.
• If script text changes, regenerate the corresponding audio files.
• Disclose that generated narration is AI voice when presenting externally.
• Use *_demo.json as the single source of truth for both text and timing.

Screen Recording Sync (Voice + Video)

To attach narration to a screen recording:

ffmpeg -y \
  -i demo/video/demo01.mov \
  -i demo/audio/demo01.mp3 \
  -filter_complex "[1:a]apad[aout]" \
  -map 0:v -map "[aout]" \
  -c:v copy -c:a aac -b:a 192k -shortest \
  demo/video/review/demo01_synced_with_voice.mp4

Optional timing offset (example +3 seconds):

ffmpeg -y \
  -i demo/video/demo01.mov \
  -i demo/audio/demo01.mp3 \
  -filter_complex "[1:a]adelay=3000|3000,apad[aout]" \
  -map 0:v -map "[aout]" \
  -c:v copy -c:a aac -b:a 192k -shortest \
  demo/video/review/demo01_synced_with_voice_offset3s.mp4

Preconditions

• OPENAI_API_KEY must be set for live audio generation.
• Network access is required for API calls.