SKILL.md
Install the belt CLI skill: npx skills add belt-sh/cli
Video Ad Specs
Create platform-specific video ads via inference.sh CLI.
Quick Start
Requires inference.sh CLI (belt). Install instructions
belt loginGenerate a vertical video ad scene
belt app run bytedance/seedance-2-0 --input '{
"prompt": "vertical video, person excitedly unboxing a product, clean modern room, bright natural lighting, social media ad style, authentic feeling",
"ratio": "9:16",
"generate_audio": true
}'
## Platform Specifications
### TikTok
| Spec | Value |
|------|-------|
| Aspect ratio | **9:16** (vertical) |
| Resolution | 1080 x 1920 px |
| Duration | 5-60 seconds (15-30s recommended) |
| File size | Max 500 MB |
| Format | MP4, MOV |
| Sound | On by default (design with sound) |
| Text safe zone | 150px from all edges |
| Hook window | **1 second** — first frame must grab attention |
### Instagram Reels
| Spec | Value |
|------|-------|
| Aspect ratio | **9:16** (vertical) |
| Resolution | 1080 x 1920 px |
| Duration | Up to 90 seconds (15-30s for ads) |
| Cover image | Separate upload, shows in grid |
| Sound | On by default |
| Caption area | Bottom 20% reserved for text overlay |
### Instagram Stories
| Spec | Value |
|------|-------|
| Aspect ratio | **9:16** |
| Resolution | 1080 x 1920 px |
| Duration | Up to 15 seconds per segment |
| Swipe-up/Link | Available for ads |
| Top/bottom | 14% top and 20% bottom = unsafe for key content |
### YouTube
| Format | Aspect | Duration | Skip |
|--------|--------|----------|------|
| Bumper | 16:9 | **6 seconds** exactly | Non-skippable |
| Non-skippable | 16:9 | **15 seconds** | Non-skippable |
| Skippable (TrueView) | 16:9 | Any length | Skip after **5 seconds** |
| Shorts | 9:16 | Up to 60 seconds | N/A |
Resolution: 1920 x 1080 (16:9) or 1080 x 1920 (Shorts)
### Facebook Feed
| Spec | Value |
|------|-------|
| Aspect ratio | **1:1** (square) or **4:5** (recommended for mobile) |
| Resolution | 1080 x 1080 or 1080 x 1350 |
| Duration | Up to 240 min (15-30s recommended) |
| Autoplay | **Silent** — captions are essential |
| Sound | 85% of Facebook video is watched **without sound** |
### LinkedIn
| Spec | Value |
|------|-------|
| Aspect ratio | **1:1** or **16:9** |
| Resolution | 1080 x 1080 or 1920 x 1080 |
| Duration | 3 seconds to 10 minutes (15-30s for ads) |
| Tone | Professional |
| Autoplay | Silent in feed |
## AIDA Framework for Video Ads
| Phase | Time | Goal | Technique |
|-------|------|------|-----------|
| **Attention** | 0-3s | Stop the scroll | Pattern interrupt, bold visual, question |
| **Interest** | 3-10s | Keep watching | State the problem, show relevance |
| **Desire** | 10-20s | Want the solution | Show the product/outcome, social proof |
| **Action** | Final 3-5s | Click/buy/sign up | Clear CTA, urgency, offer |
### Hook Techniques (First 3 Seconds)
| Technique | Example |
|-----------|---------|
| Bold statement | "This tool replaced my entire marketing team" |
| Question | "Why are you still doing this manually?" |
| Surprising visual | Unexpected transformation, before/after reveal |
| Pattern interrupt | Start mid-action, unusual angle, bright color |
| Social proof | "2 million people switched to this" |
| Pain point | "If you hate [common frustration], watch this" |
## Creating Video Ads
### Vertical (TikTok, Reels, Stories, Shorts)
Hook scene (0-3s)
belt app run google/veo-3-1-fast --input '{
"prompt": "vertical 9:16 video, close-up of hands struggling with tangled cables and messy desk, frustrated energy, shaky handheld camera, authentic social media style, bright lighting"
}'
Solution reveal (3-15s)
belt app run bytedance/seedance-2-0 --input '{
"prompt": "vertical video, smooth product reveal, clean wireless charging station on minimalist desk, satisfying organization transformation, bright modern room, social media ad aesthetic",
"ratio": "9:16",
"generate_audio": true
}'
Add voiceover
belt app run falai/dia-tts --input '{
"prompt": "[S1] Stop wasting time with this mess. This one product changed my entire setup. Everything charges. Everything is organized. Link in bio."
}'
Merge video + audio
belt app run infsh/video-audio-merger --input '{
"video": "solution-reveal.mp4",
"audio": "voiceover.mp3"
}'
Add captions (critical for silent autoplay)
belt app run infsh/caption-videos --input '{
"video": "ad-with-audio.mp4",
"caption_file": "captions.srt"
}'
### Square (Facebook, LinkedIn Feed)
belt app run google/veo-3-1-fast --input '{
"prompt": "square 1:1 video, professional person at desk discovering a new software tool, laptop screen showing clean dashboard, natural office lighting, corporate commercial style, satisfied expression"
}'
### YouTube Bumper (6 Seconds)
6-second bumper: one message, one visual, one CTA
belt app run google/veo-3-1-fast --input '{
"prompt": "6 second product ad, quick montage of a sleek app being used on phone, fast cuts, modern, energetic, brand logo reveal at end, punchy and dynamic, wide 16:9"
}'
Keep it tight
belt app run falai/dia-tts --input '{
"prompt": "[S1] Your reports. Automated. Try DataFlow free."
}'
## Captions Are Mandatory
85% of Facebook and 40%+ of Instagram video is watched on mute.
### Caption Best Practices
Rule
Reason
Always add captions
Silent viewing is the default on most platforms
Large, readable font
Small text is invisible on mobile
High contrast
White text with dark outline/background
Centered or bottom-third
Standard viewing position
Max 2 lines at a time
More text = can't be read fast enough
Key words in bold/color
Draws eye to important words
Generate captions from audio
(create SRT file from your script, then burn in)
belt app run infsh/caption-videos --input '{
"video": "ad-video.mp4",
"caption_file": "ad-captions.srt"
}'
## Ad Structure Templates
### Testimonial Ad (15-30s)
Time
Content
0-3s
Customer states the problem they had
3-15s
How they discovered and tried the product
15-25s
The specific result they achieved
25-30s
Product name + CTA
### Demo Ad (15-30s)
Time
Content
0-3s
The problem (text or visual)
3-20s
Product demo showing the solution
20-25s
Key result/benefit
25-30s
CTA + offer
### Before/After Ad (15s)
Time
Content
0-3s
"Before" state (messy, slow, frustrating)
3-5s
Transition / product introduction
5-12s
"After" state (clean, fast, satisfying)
12-15s
CTA
## Common Mistakes
Mistake
Problem
Fix
No hook in first 1-3s
Viewer scrolls past
Open with pattern interrupt
Landscape video on TikTok/Reels
Letterboxed, looks amateur
Use 9:16 for vertical platforms
No captions
Most viewers watch silent
Always add captions
CTA too late
Viewers already left
Clear CTA within last 5 seconds
Too long for platform
Forced skip or dropout
Match platform duration norms
Same ad for all platforms
Wrong specs, wrong tone
Create platform-specific versions
Logo in first 3s
Feels like a commercial, gets skipped
Save branding for the end
Text in unsafe zones
Cut off by platform UI
Check safe zone per platform
## Checklist
- Correct aspect ratio for target platform
- Hook in first 1-3 seconds
- Captions added (readable, high contrast)
- CTA clear and within final 5 seconds
- Duration matches platform norms
- Text outside platform unsafe zones
- Audio designed for both sound-on and sound-off
- Platform-specific version (not one-size-fits-all)
## Related Skills
npx skills add inference-sh/skills@ai-video-generation
npx skills add inference-sh/skills@video-prompting-guide
npx skills add inference-sh/skills@text-to-speech
npx skills add inference-sh/skills@prompt-engineering