Convert .mov to .mp4 recursively in folder (Go)

main.go

package main

import (
	"fmt"
	ffmpeg "github.com/u2takey/ffmpeg-go"
	"log"
	"os"
	"path/filepath"
	"strings"
)

func main() {
	path := "YOUR DIRECTORY PATH :-)"
	wDir, _ := os.Getwd()

	outputFolder := wDir + "/output"
	os.Mkdir(outputFolder, 0755)

	var movFiles []string

	// Find .mov files
	err := filepath.Walk(path, func(filePath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}

		// If file is a .mov file
		if filepath.Ext(filePath) == ".mov" {
			movFiles = append(movFiles, filePath)
		}

		return nil
	})

	if err != nil {
		log.Println(err)
	}

	// Convert .mov files to .mp4
	for _, movFile := range movFiles {
		// Output path
		fileName := FileNameWithoutExt(filepath.Base(movFile))
		outputPath := outputFolder + "/" + fileName + ".mp4"

		// ffmpeg
		println("Converting " + movFile)
		args := ffmpeg.KwArgs{
			"c:v":    "libx265",
			"preset": "medium",
		}
		ffmpegError := ffmpeg.Input(movFile).Output(outputPath, args).ErrorToStdOut().Run()

		if ffmpegError != nil {
			panic(ffmpegError)
		}

		// Size before
		sizeBefore := GetFileSize(movFile)
		sizeAfter := GetFileSize(outputPath)

		// Print size
		println("Size before: " + GetFileSizeInHumanFormat(sizeBefore))
		println("Size after: " + GetFileSizeInHumanFormat(sizeAfter))
	}
}

func GetFileSizeInHumanFormat(fileSize int64) string {
	if fileSize < 1024 {
		return fmt.Sprintf("%d B", fileSize)
	}
	if fileSize < 1024*1024 {
		return fmt.Sprintf("%d KB", fileSize/1024)
	}
	if fileSize < 1024*1024*1024 {
		return fmt.Sprintf("%d MB", fileSize/1024/1024)
	}
	return fmt.Sprintf("%d GB", fileSize/1024/1024/1024)
}

func GetFileSize(filePath string) int64 {
	file, err := os.Open(filePath)
	if err != nil {
		log.Fatal(err)
	}
	defer func(file *os.File) {
		err := file.Close()
		if err != nil {
			log.Fatal(err)
		}
	}(file)

	fileInfo, fileInfoError := file.Stat()
	if fileInfoError != nil {
		log.Fatal(fileInfoError)
	}

	return fileInfo.Size()
}

func FileNameWithoutExt(fileName string) string {
	return strings.TrimSuffix(fileName, filepath.Ext(fileName))
}

You need to have ffmpeg installed.

For Mac users with Homebrew: brew install ffmpeg