Oatda Video Ad Creator

OATDA Video Ad Creator

Build a short (15–30s) branded video ad for the user's product from start to finish: script → OATDA TTS voiceover → OATDA AI video hook clip → product screenshots → Remotion composition → ffmpeg mux → QA gate.

Audience & Inputs

The user brings their own brand — logo, colors, fonts — plus product screenshots and the message they want to convey. Collect before starting:

• Brand kit: primary/accent colors (hex), logo file, preferred font
• Product screenshots or URLs to capture
• Key message: 3–4 short claims and one call to action (CTA)
• Target duration and aspect ratio (default 16:9, 1080p, ~20–25s)

The Remotion scaffold lives in this repo at templates/video-ad-remotion/ — copy it into a local project folder (e.g. ~/video-ad/) and work there.

Scene Types

Production Workflow

1. Script first. Write VO sentences (short, punchy). Calibrate duration: a typical TTS voice at speed 1.0 reads ≈ 36 words in ≈ 21s; speed 1.2 ≈ 17s. Target: VO duration + 0.7s inter-sentence gaps ≤ ad length limit.
2. AI hook clip (e.g. seedance-1-5-pro):
   • Render a draft first (480p, roughly 40% cheaper) → verify via frame extraction + image model review before paying for 1080p
   • Final: POST https://oatda.com/api/v1/llm/generate-video via direct curl (see pitfalls), ~100–120s generation, provider field REQUIRED
   • model_params: {"ratio":"16:9","resolution":"1080p","watermark":false,"generate_audio":false,"draft":false}
   • Prompt rule: motion only, no text or logos in the AI clip — text comes as a Remotion overlay
3. TTS voiceover: generate_speech per sentence → download immediately (signed URLs expire ~8 min) → concat with 0.7s gaps + 0.3s lead + 0.5s tail (ffmpeg -f concat, paths relative to the .txt!) → master chain → MP3 256k
4. Music mix: voice + licensed track @ ~0.28 volume, amix normalize=0, fade out over the last 1.5s
5. Screenshots: google-chrome --headless --virtual-time-budget=10000 (client-rendered pages need it). Auth-walled pages → screenshot manually in a logged-in browser, or build a CodeScene mock instead
6. Remotion render: npx remotion render src/index.ts <composition-id> out/raw.mp4 (~2 min)
7. Mux: ffmpeg -i raw.mp4 -i mixed.mp3 -map 0:v -map 1:a -c:v copy -c:a aac -b:a 192k — never -shortest
8. QA gate: see below — mandatory before delivering any draft

Timing Model (30fps)

VO start + ~0.5s pre-roll per scene; scene length in frames = round(seconds × 30). Derive scene boundaries from the VO: run silencedetect on the voiceover, treat gaps > 0.9s as sentence/scene boundaries.

ffmpeg -i vo.mp3 -af silencedetect=noise=-35dB:d=0.3 -f null - 2>&1 | grep silence_

Project Layout

• Compositions: <project>/src/Ads/*.tsx (one file per ad, scenes as components)
• Registration: <project>/src/Root.tsx (one <Composition> per ad)
• Media assets: <project>/public/videos/, <project>/public/images/screenshots/ (accessed via staticFile('...'))
• Voiceover: <project>/audio/ (vo-*.wav, vo-final.mp3, mixed.mp3)
• Render output: <project>/out/ (raw.mp4, final.mp4)

Known Pitfalls (hard-won — read before starting)

• AI video generation can outlive tool timeouts on 1080p full quality (~100s+ generation). Call the video API with direct curl using your OATDA API key from the OATDA_API_KEY environment variable (never log the key), and allow an exec timeout ≥ 120s.
• TTS download URLs expire ~8 min ({"error":"Unauthorized"} after that). Generation and download must happen back-to-back. Corrupt-file check: file *.wav must report audio, not JSON.
• ffmpeg concat paths are relative to the concat .txt file's location, not the current working directory.
• Headless Chrome screenshots of client-rendered pages come back empty without --virtual-time-budget=10000.
• Remotion needs <OffthreadVideo> for h264 MP4s — plain <Video> fails.
• Remotion renders silent — audio is always muxed separately with ffmpeg afterwards.

Render QA Gate (mandatory before delivering a draft)

Run every check below on the final muxed MP4. Emit one PASS/FAIL line per check in the delivery report; fix and re-render on any FAIL.

1. Specs — ffprobe duration within ±0.5s of plan, expected resolution/fps, exactly 1 video + 1 audio stream.
2. Black frames — blackdetect: no black intervals longer than 0.2s.
3. VO silence — silencedetect: no unexpected voiceover silence gaps longer than 1s.
4. Loudness — volumedetect: mean volume between −17 and −20 dB.
5. Visual review — extract 1 frame per scene boundary + 1 mid-scene frame; each frame must be non-empty (not black/blank), then review visually.
6. Audio coverage — audio duration ≥ video duration − 0.2s.

# 1 — specs
ffprobe -v error -show_entries format=duration -show_entries stream=codec_type,width,height,r_frame_rate final.mp4
# 2 — black intervals (want: none > 0.2s)
ffmpeg -i final.mp4 -vf blackdetect=d=0.2:pic_th=0.98 -f null - 2>&1 | grep blackdetect
# 3 — VO silence gaps (want: none > 1s mid-sentence)
ffmpeg -i final.mp4 -af silencedetect=noise=-35dB:d=1 -f null - 2>&1 | grep silence_
# 4 — mean volume (want: −17 to −20 dB)
ffmpeg -i final.mp4 -af volumedetect -f null - 2>&1 | grep mean_volume
# 5 — QA frames (one per boundary/mid-scene, then inspect)
ffmpeg -i final.mp4 -vf "select='eq(n,60)+eq(n,250)+eq(n,400)+eq(n,650)'" -vsync vfr qa_%d.png

Cost Control

Render hook-clip drafts at 480p and only promote to 1080p once framing and motion are approved. Draft iterations typically cost a fraction of the final render; TTS is negligible.

Music & Licensing

Only use music you are licensed to use. CC-BY tracks (e.g. Kevin MacLeod, incompetech.com) require crediting the artist in the video description wherever the ad is published, for example:

Music: Wallpaper — Kevin MacLeod, incompetech.com

Honesty of On-Screen Numbers

If the ad quotes live counts or metrics, keep them in the composition's defaultProps as the single source of truth, refresh them per render, and prefer rounded-up floors on screen and in VO ("200+") so the ad never states a number that has since dropped.