Convert mp3s to ogg vorbis recursively (ffmpeg required)

package main

import (
    "fmt"
    "os"
    "os/exec"
    "path/filepath"
)

func main() {
    folder := os.Args[1]

    err := filepath.Walk(folder, func(path string, info os.FileInfo, err error) error {
        if err != nil {
            fmt.Printf("error accessing path %q: %v\n", path, err)
            return err
        }
        if info.IsDir() || filepath.Ext(path) != ".mp3" {
            return nil
        }

        const command = "ffmpeg"
        var output = path[:len(path) - 3] + "ogg"
        var arguments = []string{
            "-i",
            path,
            "-vn",
            "-c:a",
            "libvorbis",
            "-q:a",
            "3",
            output,
        }
        cmd := exec.Command(command, arguments...)
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr
        err = cmd.Run()
        if err != nil {
            panic(err)
        }
        // fmt.Printf("file %s converted to %s", path, output)
        err = os.Remove(path)
        if err != nil {
            panic(err)
        }
        return nil
    })
    if err != nil {
        fmt.Printf("error walking the path %q: %v\n", folder, err)
    }
}