sticker

go-sticker

A high-performance Go library that processes images and animated content into WhatsApp-compliant stickers. The library is fast, accurate, and battle-tested against WhatsApp's strict sticker validation rules.

Features

• Fully compliant static and animated WebP sticker generation
• Transparent pipeline that leverages ffmpeg for maximum performance, with a pure-Go fallback for static images
• Built-in size optimization loop out of the box
• Simple thread-safe interface supporting concurrency limits

Prerequisites

It is highly recommended to install ffmpeg for performance and to enable animated sticker processing. Without ffmpeg, go-sticker will only process static images using standard Go libraries, and animation processing will fail.

# Ubuntu/Debian
sudo apt-get install ffmpeg

# MacOS
brew install ffmpeg

Quick Install

go get github.com/miruchigawa/sticker-go

Usage

package main

import (
	"context"
	"fmt"
	"os"
	"github.com/miruchigawa/sticker-go"
)

func main() {
	// Initialize a new processor
	proc := sticker.New()

	// Static image processing
	staticFile, _ := os.Open("image.png")
	staticSticker, err := proc.Process(context.Background(), staticFile, "image/png")
	if err != nil {
		panic(err)
	}
	os.WriteFile("static_sticker.webp", staticSticker, 0644)

	// Animated processing (requires ffmpeg)
	animFile, _ := os.Open("video.mp4")
	animSticker, err := proc.Process(context.Background(), animFile, "video/mp4")
	if err != nil {
		panic(err)
	}
	os.WriteFile("animated_sticker.webp", animSticker, 0644)
}

Validation

res, err := proc.Validate(staticSticker)
if err != nil {
    panic(err)
}
if res.Valid {
    fmt.Println("This is a valid WhatsApp sticker!")
} else {
    fmt.Println("Invalid sticker:", res.Errors)
}

ProcessOptions

You can customize processing behavior by modifying the defaults:

WhatsApp Sticker Spec

All outputs comply strictly with:

Fallback Behavior

If ffmpeg is not found, go-sticker automatically degrades to use golang.org/x/image and github.com/chai2010/webp to handle static PNG/JPEG processing. Animations cannot be processed strictly in Go, so calling ProcessAnimation will return ErrFFmpegNotFound.

Benchmarks

BenchmarkStaticProcess-4              14          83998350 ns/op           86065 B/op        385 allocs/op
BenchmarkAnimProcess-4                 2         854138818 ns/op         1424972 B/op        800 allocs/op