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 login

# Generate 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

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