Openmontage Video Edit

---
name: openmontage-video-edit
description: 面向视频剪辑日常任务的 ffmpeg 命令速查手册，覆盖裁剪、转码、缩放、变速、音视频处理、拼接、水印、画中画、滤镜、字幕、防抖、调色、压缩、幻灯片、章节标记、响度归一化等常见操作。
version: "1.0.0"
author: playhouse
license: MIT
---

# 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`.