先按照ffmpeg的安装攻略，搞定你CentOS上的ffmpeg，我目前使用的版本是3.0.2
然后直接上代码

package main

import (
    "fmt"
    "log"
    "os"
    "os/exec"
    "time"
)

func main() {
    var srcFileName, outputfilename string
    log.SetFlags(log.Lshortfile | log.Ldate | log.Ltime)

    if len(os.Args) != 3 {
        fmt.Println("简单的转码服务，利用FFMPEG和编码器转换成MP4.")
        fmt.Println("使用：[输入文件路径] [输出文件路径]")
        os.Exit(1)
    } else {
        srcFileName = os.Args[1]
        outputfilename = os.Args[2]
    }
    param := "ffmpeg -y -i " + srcFileName + " -metadata:s:v rotate=0  -vf fps=15,setdar=dar=1 -s 480x480 -pix_fmt yuv420p -strict -2 -c:v h264 -b:v 500k -b:a 48k -ss 0 -t 300 -threads 2 " + outputfilename + ""
    fmt.Println("parm : ", param)
    start := time.Now()
    _, err := exec.Command("bash", "-c", param).CombinedOutput()
    if err != nil {

        fmt.Println("error: " + err.Error())

    } else {
        fmt.Println(" out file : ", outputfilename, " exec time  ", time.Now().Sub(start).Seconds())
    }
}

执行下：

go run main.go simple.mov simple_1.mp4