GoMontage

GoMontage is a programmatic video editing framework for Go. Instead of reaching for a GUI editor, you describe your edit in code — trim clips, arrange tracks, layer audio, apply effects — and GoMontage compiles it into an FFmpeg command and renders it. If you can write Go, you can automate video production.

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How GoMontage Works

GoMontage has four layers that take your code all the way to a rendered video file:

1. Clips — Load media with clip.NewVideo(), clip.NewAudio(), etc. Clips are immutable; every transform (.Trim(), .WithVolume()) returns a new instance.
2. Timeline — Add clips to named video and audio tracks using tl.AddVideoTrack(). Positioning is explicit: timeline.At(5 * time.Second) places a clip at the 5-second mark.
3. Compiler — When you call tl.Export(), the Compiler walks the timeline and builds an FFmpeg filter graph — handling scaling, mixing, sequencing, and effects automatically.
4. Engine — The filter graph is handed to the Engine, which constructs the final FFmpeg command and runs it.

You write Go. GoMontage handles the FFmpeg.

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Requirements

• Go 1.25+
• FFmpeg & ffprobe installed and available in PATH

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Install

go install github.com/ahmedhodiani/gomontage/cmd/gomontage@latest

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Quick Start

1. Scaffold a project

gomontage init my-video
cd my-video

This creates the project structure with a starter main.go, config file, and folders for your media files.

2. Add your media

Drop video, audio, and image files into resources/video/, resources/audio/, etc.

3. Edit main.go

package main

import (
    "time"

    "github.com/ahmedhodiani/gomontage/clip"
    "github.com/ahmedhodiani/gomontage/export"
    "github.com/ahmedhodiani/gomontage/timeline"
)

func main() {
    tl := timeline.New(timeline.Config{
        Width:  1920,
        Height: 1080,
        FPS:    30,
    })

    video := clip.NewVideo("resources/video/footage.mp4")
    trimmed := video.Trim(0, 30*time.Second)

    main := tl.AddVideoTrack("main")
    main.Add(trimmed, timeline.At(0))

    tl.Export(export.YouTube1080p(), "output/final.mp4")
}

4. Render

gomontage run

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CLI Commands

Command	Description
gomontage init <name>	Scaffold a new project
gomontage run	Run main.go to render the video
gomontage probe <file>	Inspect media file metadata
gomontage validate	Validate the project config
gomontage docs	Generate API documentation into docs/

Generate docs

gomontage docs

Writes a full markdown API reference and guides into the docs/ directory.