CRITICAL GUIDELINES

Windows File Path Requirements

MANDATORY: Always Use Backslashes on Windows for File Paths

When using Edit or Write tools on Windows, you MUST use backslashes (\) in file paths, NOT forward slashes (/).

TikTok Viral Video Creator

Purpose

Transform any video into a TikTok-optimized viral format with:

9:16 vertical aspect ratio (1080x1920)
Auto-generated captions with CapCut-style word highlighting
Hook optimization for the critical first 1-3 seconds
Platform-compliant encoding (H.264, yuv420p, max 287MB)
Optimal duration guidance (15-60 seconds sweet spot)

Quick Start

Basic TikTok Conversion

# Simple conversion to TikTok format
ffmpeg -i input.mp4 \
  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black,setsar=1" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k -ar 44100 \
  -pix_fmt yuv420p \
  -movflags +faststart \
  -t 60 \
  output_tiktok.mp4

Complete TikTok Workflow

Step 1: Analyze Input

# Check source video properties
ffprobe -v quiet -print_format json -show_format -show_streams input.mp4

Key metrics to evaluate:

Duration (TikTok optimal: 15-60s, max 10 min)
Resolution (need to crop/scale for 9:16)
Audio quality (TikTok requires good audio)

Step 2: Create 9:16 Vertical Format

From Horizontal (16:9) Video

# Option A: Center crop (best for talking head/single subject)
ffmpeg -i horizontal.mp4 \
  -vf "crop=ih*9/16:ih,scale=1080:1920" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  -pix_fmt yuv420p -movflags +faststart \
  output_tiktok.mp4

# Option B: Letterbox with blur background (preserves full frame)
ffmpeg -i horizontal.mp4 \
  -filter_complex "[0:v]scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2[fg];[0:v]scale=1080:1920,boxblur=20:20[bg];[bg][fg]overlay=(W-w)/2:(H-h)/2" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  -pix_fmt yuv420p -movflags +faststart \
  output_tiktok.mp4

# Option C: Split screen (original top + zoomed bottom)
ffmpeg -i horizontal.mp4 \
  -filter_complex "[0:v]scale=1080:-2[top];[0:v]crop=ih*9/16:ih,scale=1080:-2[bottom];[top][bottom]vstack=inputs=2,scale=1080:1920" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  -pix_fmt yuv420p -movflags +faststart \
  output_tiktok.mp4

From Square (1:1) Video

# Extend vertically with blur background
ffmpeg -i square.mp4 \
  -filter_complex "[0:v]scale=1080:1080[fg];[0:v]scale=1080:1920,boxblur=15:15[bg];[bg][fg]overlay=0:(H-h)/2" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  -pix_fmt yuv420p -movflags +faststart \
  output_tiktok.mp4

Step 3: Add Viral Captions

Auto-Generate Captions with Whisper (FFmpeg 8.0+)

# Generate SRT from video (FFmpeg 8.0+ with Whisper)
ffmpeg -i input.mp4 -vn \
  -af "whisper=model=ggml-base.bin:language=auto:format=srt" \
  captions.srt

# Burn captions with TikTok-style appearance
ffmpeg -i input_tiktok.mp4 \
  -vf "subtitles=captions.srt:force_style='FontName=Arial Black,FontSize=48,PrimaryColour=&HFFFFFF,OutlineColour=&H000000,Outline=4,Shadow=0,Bold=1,Alignment=2,MarginV=200'" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a copy \
  output_with_captions.mp4

Animated Word-by-Word Captions (CapCut Style)

See the viral-video-animated-captions skill for advanced word-level highlighting similar to CapCut's auto-captions.

Step 4: Add Hook Elements (First 1-3 Seconds)

Text Hook Overlay

# Add attention-grabbing text in first 3 seconds
ffmpeg -i input.mp4 \
  -vf "drawtext=text='WAIT FOR IT...':fontfile=/path/to/bold-font.ttf:fontsize=72:fontcolor=yellow:borderw=4:bordercolor=black:x=(w-tw)/2:y=h*0.15:enable='between(t,0,3)'" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a copy \
  output_with_hook.mp4

Visual Hook Effects

# Zoom pulse effect - 60fps for smooth motion, optimized timing for 1.3s attention window
# 12% amplitude at ~1.3Hz (sin(t*8) = 8 rad/s) creates highly visible pulsing on mobile
ffmpeg -i input.mp4 \
  -vf "fps=60,zoompan=z='if(lt(t,1.5),1+0.12*sin(t*8),1)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':s=1080x1920" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  output_hook_zoom.mp4

Step 5: Optimize Duration

# Trim to optimal TikTok length (15-60s)
ffmpeg -i input.mp4 \
  -ss 00:00:00 -t 00:00:45 \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k \
  -pix_fmt yuv420p -movflags +faststart \
  output_trimmed.mp4

Step 6: Extract Cover Frame

# Extract thumbnail at peak moment (adjust time)
ffmpeg -i output_tiktok.mp4 -ss 00:00:03 -vframes 1 \
  -vf "scale=1080:1920" \
  cover_image.jpg

Complete One-Command Preset

# Full TikTok optimization pipeline
ffmpeg -i input.mp4 \
  -filter_complex "
    [0:v]scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black[v1];
    [v1]drawtext=text='YOUR HOOK TEXT':fontsize=64:fontcolor=white:borderw=3:bordercolor=black:x=(w-tw)/2:y=h*0.12:enable='between(t,0,2.5)'[v2];
    [0:a]loudnorm=I=-16:TP=-1.5:LRA=11[a]
  " \
  -map "[v2]" -map "[a]" \
  -c:v libx264 -preset fast -crf 23 \
  -c:a aac -b:a 128k -ar 44100 \
  -pix_fmt yuv420p \
  -movflags +faststart \
  -t 60 \
  -metadata title="Your Video Title" \
  output_tiktok_final.mp4

TikTok Technical Requirements (2025-2026)

Specification	Requirement	Optimal Value
Aspect Ratio	9:16 (vertical)	Required
Resolution	1080x1920 (recommended)	1080x1920 (TikTok compresses 4K)
Video Codec	H.264 (required)	H.264 High Profile, Level 4.1
Audio Codec	AAC	AAC-LC, 192 kbps
Audio Loudness	-10 to -12 LUFS	-11 LUFS (mobile-optimized)
True Peak	-1.5 dBTP max	Prevents distortion
Frame Rate	24-60 fps	30 fps (60 fps for sports/action only)
Bitrate (30fps)	6-8.5 Mbps	7 Mbps VBR optimal
CRF	21-23	CRF 22 (best balance)
Keyframe Interval	2-3 seconds	Every 60-90 frames at 30fps
Max File Size	287 MB (iOS), 72 MB (Android web)	Target: <100 MB
Max Duration	10 minutes	Optimal: 21-34 seconds
Optimal Duration	21-34 seconds	Highest completion rate
Pixel Format	yuv420p	Required, Rec.709

Viral Optimization Tips

Hook Strategies (First 1-3 Seconds)

Pattern Interrupt: Unexpected visual/sound
Curiosity Gap: "You won't believe what happens..."
Direct Address: "Stop scrolling if you..."
Controversy: Bold claim or opinion
Transformation: Before/after tease

Retention Boosters

# Add subtle zoom throughout video - 0.2%/sec is minimum perceptible on mobile
# Keeps viewers engaged with subconscious motion without being distracting
ffmpeg -i input.mp4 \
  -vf "zoompan=z='1+0.002*t':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':s=1080x1920" \
  -c:v libx264 -preset fast -crf 23 \
  output_slow_zoom.mp4

# Add subtle shake/movement
ffmpeg -i input.mp4 \
  -vf "crop=1060:1900:(10+5*sin(t*8)):(10+5*cos(t*6)),scale=1080:1920" \
  -c:v libx264 -preset fast -crf 23 \
  output_subtle_shake.mp4

Audio Optimization (2025-2026 Research)

TikTok Audio Targets:

Loudness: -10 to -12 LUFS (louder wins on mobile speakers)
True Peak: -1.5 dBTP maximum (prevent distortion)
Strategy: Upload hotter than platform target for better mobile experience

# Normalize audio for TikTok - optimized for mobile playback
# -11 LUFS target: louder than YouTube (-14) but prevents over-compression
ffmpeg -i input.mp4 \
  -af "loudnorm=I=-11:TP=-1.5:LRA=11" \
  -c:v copy \
  output_normalized_tiktok.mp4

# Boost voice clarity with compression
ffmpeg -i input.mp4 \
  -af "highpass=f=100,lowpass=f=8000,compand=attacks=0:points=-80/-900|-45/-15|-27/-9|0/-7|20/-7:gain=5,loudnorm=I=-11:TP=-1.5" \
  -c:v copy \
  output_voice_boost.mp4

# Bass boost for music content
ffmpeg -i input.mp4 \
  -af "bass=g=6:f=100,loudnorm=I=-11:TP=-1.5:LRA=11" \
  -c:v copy \
  output_bass_boost.mp4

Batch Processing

#!/bin/bash
# batch_tiktok.sh - Convert multiple videos to TikTok format

for input in *.mp4; do
    output="tiktok_${input}"
    ffmpeg -i "$input" \
      -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black" \
      -c:v libx264 -preset fast -crf 23 \
      -c:a aac -b:a 128k \
      -pix_fmt yuv420p -movflags +faststart \
      -t 60 \
      "$output"
done

Output Checklist

Before uploading, verify:

# Verify TikTok compliance
ffprobe -v error -select_streams v:0 \
  -show_entries stream=width,height,codec_name,pix_fmt,r_frame_rate \
  -of csv=p=0 output_tiktok.mp4

# Expected: 1080,1920,h264,yuv420p,30/1

# Check file size (must be under 287MB)
ls -lh output_tiktok.mp4

Related Skills

viral-video-platform-specs - All platform upload requirements
viral-video-hook-templates - 10 proven hook patterns
viral-video-animated-captions - CapCut-style word highlighting
ffmpeg-captions-subtitles - Full caption system

/ffmpeg-viral-tiktok