---
name: video-edit
description: |
  Edit videos locally using ffmpeg. Trim, concat, resize, speed, overlay, extract audio, compress, and convert.
  Use when: (1) Trimming or cutting video segments, (2) Concatenating multiple clips, (3) Resizing video for social platforms,
  (4) Extracting or replacing audio, (5) Compressing video, (6) Converting video formats, (7) Getting video info.
---

# Video Edit

Edit videos locally by running ffmpeg/ffprobe directly. No wrapper scripts needed.

## Prerequisites

Install ffmpeg (includes ffprobe):

```bash
# macOS
brew install ffmpeg

# Ubuntu/Debian
sudo apt update && sudo apt install -y ffmpeg

# Verify
ffmpeg -version && ffprobe -version
```

## Quick Reference

### Get video info

```bash
ffprobe -v quiet -print_format json -show_format -show_streams video.mp4
```

### Trim

```bash
ffmpeg -y -ss 00:00:30 -to 00:01:45 -i video.mp4 -c copy trimmed.mp4
```

### Concatenate clips

```bash
# 1. Create a file list
printf "file '%s'\n" clip1.mp4 clip2.mp4 clip3.mp4 > list.txt

# 2. Concat with stream copy
ffmpeg -y -f concat -safe 0 -i list.txt -c copy joined.mp4
```

### Resize for platform

```bash
ffmpeg -y -i video.mp4 \
  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black" \
  -c:a copy tiktok.mp4
```

### Change speed

```bash
# 2x faster
ffmpeg -y -i video.mp4 -filter:v "setpts=0.5*PTS" -filter:a "atempo=2.0" fast.mp4

# 0.5x (slow motion)
ffmpeg -y -i video.mp4 -filter:v "setpts=2.0*PTS" -filter:a "atempo=0.5" slow.mp4
```

### Extract audio

```bash
ffmpeg -y -i video.mp4 -vn -acodec libmp3lame audio.mp3
```

### Replace audio

```bash
ffmpeg -y -i video.mp4 -i audio.mp3 -c:v copy -map 0:v:0 -map 1:a:0 -shortest output.mp4
```

### Compress

```bash
ffmpeg -y -i video.mp4 -crf 23 -preset medium -c:a copy compressed.mp4
```

### Convert format

```bash
ffmpeg -y -i video.mov output.mp4
```

### Add image overlay

```bash
# Logo in top-right corner
ffmpeg -y -i video.mp4 -i logo.png \
  -filter_complex "overlay=W-w-10:10" -c:a copy watermarked.mp4
```

## Platform Presets

| Platform   | Resolution  | Scale + pad filter                                                                                    |
|------------|-------------|-------------------------------------------------------------------------------------------------------|
| TikTok     | 1080 x 1920 | `scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black`       |
| YouTube    | 1920 x 1080 | `scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black`       |
| Instagram  | 1080 x 1350 | `scale=1080:1350:force_original_aspect_ratio=decrease,pad=1080:1350:(ow-iw)/2:(oh-ih)/2:black`       |
| Square     | 1080 x 1080 | `scale=1080:1080:force_original_aspect_ratio=decrease,pad=1080:1080:(ow-iw)/2:(oh-ih)/2:black`       |
| Twitter/X  | 1920 x 1080 | `scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black`       |

Use the filter with: `ffmpeg -y -i input.mp4 -vf "<filter>" -c:a copy output.mp4`

## Tips

- Always use `-y` to overwrite output without prompting.
- Use `-c copy` when you only need to cut/join (no re-encoding, very fast).
- Lower CRF = better quality, larger file. Range 18-28 is typical; 23 is the default.
- For detailed recipes and flag explanations, see `references/operations.md`.