Media Processing Skill

Quick Summary

Goal: Process multimedia files using FFmpeg for video/​audio encoding, conversion, streaming, and filtering.

Workflow:

1. Identify -- Match input to correct FFmpeg operation (convert, trim, merge, compress)
2. Execute -- Run FFmpeg command with appropriate codec and quality settings
3. Verify -- Check output file integrity and quality

Key Rules:

• Use tool selection table to pick correct FFmpeg operation
• Prefer hardware-accelerated encoding when available
• Always verify output file exists and is playable

Be skeptical. Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence percentages (Idea should be more than 80%).

Media Processing Skill

Process video, audio, and images using FFmpeg, ImageMagick, and RMBG CLI tools.

Tool Selection

Installation

# macOS
brew install ffmpeg imagemagick
npm install -g rmbg-cli

# Ubuntu/​Debian
sudo apt-get install ffmpeg imagemagick
npm install -g rmbg-cli

# Verify
ffmpeg -version && magick -version && rmbg --version

Essential Commands

# Video: Convert/​re-encode
ffmpeg -i input.mkv -c copy output.mp4
ffmpeg -i input.avi -c:v libx264 -crf 22 -c:a aac output.mp4

# Video: Extract audio
ffmpeg -i video.mp4 -vn -c:a copy audio.m4a

# Image: Convert/​resize
magick input.png output.jpg
magick input.jpg -resize 800x600 output.jpg

# Image: Batch resize
mogrify -resize 800x -quality 85 *.jpg

# Background removal
rmbg input.jpg                          # Basic (modnet)
rmbg input.jpg -m briaai -o output.png  # High quality
rmbg input.jpg -m u2netp -o output.png  # Fast

Key Parameters

FFmpeg:

• -c:v libx264 - H.264 codec
• -crf 22 - Quality (0-51, lower=better)
• -preset slow - Speed/​compression balance
• -c:a aac - Audio codec

ImageMagick:

• 800x600 - Fit within (maintains aspect)
• 800x600^ - Fill (may crop)
• -quality 85 - JPEG quality
• -strip - Remove metadata

RMBG:

• -m briaai - High quality model
• -m u2netp - Fast model
• -r 4096 - Max resolution

References

Detailed guides in references/:

• ffmpeg-encoding.md - Codecs, quality, hardware acceleration
• ffmpeg-streaming.md - HLS/​DASH, live streaming
• ffmpeg-filters.md - Filters, complex filtergraphs
• imagemagick-editing.md - Effects, transformations
• imagemagick-batch.md - Batch processing, parallel ops
• rmbg-background-removal.md - AI models, CLI usage
• common-workflows.md - Video optimization, responsive images, GIF creation
• troubleshooting.md - Error fixes, performance tips
• format-compatibility.md - Format support, codec recommendations

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[IMPORTANT] Use TaskCreate to break ALL work into small tasks BEFORE starting — including tasks for each file read. This prevents context loss from long files. For simple tasks, AI MUST ATTENTION ask user whether to skip.

<!-- SYNC:ai-mistake-prevention -->

AI Mistake Prevention — Failure modes to avoid on every task:

Check downstream references before deleting. Deleting components causes documentation and code staleness cascades. Map all referencing files before removal. Verify AI-generated content against actual code. AI hallucinates APIs, class names, and method signatures. Always grep to confirm existence before documenting or referencing. Trace full dependency chain after edits. Changing a definition misses downstream variables and consumers derived from it. Always trace the full chain. Trace ALL code paths when verifying correctness. Confirming code exists is not confirming it executes. Always trace early exits, error branches, and conditional skips — not just happy path. When debugging, ask "whose responsibility?" before fixing. Trace whether bug is in caller (wrong data) or callee (wrong handling). Fix at responsible layer — never patch symptom site. Assume existing values are intentional — ask WHY before changing. Before changing any constant, limit, flag, or pattern: read comments, check git blame, examine surrounding code. Verify ALL affected outputs, not just the first. Changes touching multiple stacks require verifying EVERY output. One green check is not all green checks. Holistic-first debugging — resist nearest-attention trap. When investigating any failure, list EVERY precondition first (config, env vars, DB names, endpoints, DI registrations, data preconditions), then verify each against evidence before forming any code-layer hypothesis. Surgical changes — apply the diff test. Bug fix: every changed line must trace directly to the bug. Don't restyle or improve adjacent code. Enhancement task: implement improvements AND announce them explicitly. Surface ambiguity before coding — don't pick silently. If request has multiple interpretations, present each with effort estimate and ask. Never assume all-records, file-based, or more complex path.

<!-- /​SYNC:ai-mistake-prevention --> <!-- SYNC:critical-thinking-mindset -->

Critical Thinking Mindset — Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence >80% to act. Anti-hallucination: Never present guess as fact — cite sources for every claim, admit uncertainty freely, self-check output for errors, cross-reference independently, stay skeptical of own confidence — certainty without evidence root of all hallucination.

<!-- /​SYNC:critical-thinking-mindset --> <!-- SYNC:critical-thinking-mindset:reminder -->

MUST ATTENTION apply critical thinking — every claim needs traced proof, confidence >80% to act. Anti-hallucination: never present guess as fact.

<!-- /​SYNC:critical-thinking-mindset:reminder --> <!-- SYNC:ai-mistake-prevention:reminder -->

MUST ATTENTION apply AI mistake prevention — holistic-first debugging, fix at responsible layer, surface ambiguity before coding, re-read files after compaction.

<!-- /​SYNC:ai-mistake-prevention:reminder -->

Closing Reminders

• MANDATORY IMPORTANT MUST ATTENTION break work into small todo tasks using TaskCreate BEFORE starting
• MANDATORY IMPORTANT MUST ATTENTION search codebase for 3+ similar patterns before creating new code
• MANDATORY IMPORTANT MUST ATTENTION cite file:line evidence for every claim (confidence >80% to act)
• MANDATORY IMPORTANT MUST ATTENTION add a final review todo task to verify work quality

[TASK-PLANNING] Before acting, analyze task scope and systematically break it into small todo tasks and sub-tasks using TaskCreate.