This is the Go version of encode.py written for Windows 7

encode.go

// This is a go script that encodes all files with mkv extension in the current
// working directory.
//
// NOTE: To use this script on Windows, you must download the fontconfig file
// which can be found at:
//		http://ffmpeg.zeranoe.com/forum/viewtopic.php?f=10&t=318&start=10
//
//
// Sources:
//		http://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"os/signal"
	"strings"
)

const (
	CRF_VALUE = "21"
	PROFILE   = "high"
	PRESET    = "fast"

	FFMPEG_PATH    = "C:\\ffmpeg\\bin\\ffmpeg.exe"
	FONT_DIR       = "C:\\ffmpeg\\bin\\fonts"
	FC_CONFIG_DIR  = "C:\\ffmpeg\\bin\\fonts"
	FC_CONFIG_FILE = "C:\\ffmpeg\\bin\\fonts\\fonts.conf"

	EXTENSION = "mkv"

	ATTACHMENTS = "fonts"
	ASS         = "temp.ass"
)

// Remove the following:
// 	- symbolic links for fonts
// 	- ATTACHMENTS directory
// 	- extracted subtitles
func cleanup() {
	os.Chdir(ATTACHMENTS)
	fileInfoList, _ := ioutil.ReadDir(".")
	for _, fileInfo := range fileInfoList {
		link := fmt.Sprintf("%s\\%s", FONT_DIR, fileInfo.Name())
		if err := exec.Command("cmd", "/c", "DEL", link).Run(); err != nil {
			fmt.Println(err)
		}
	}
	os.Chdir("..")

	os.RemoveAll(ATTACHMENTS)
	os.Remove(ASS)
}

// 1. Create ATTACHMENTS directory
// 2. Dump mkv attachments into ATTACHMENTS directory
// 3. Create symlinks to FC_CONFIG_DIR
func installFonts(name string) {
	os.Mkdir(ATTACHMENTS, os.ModeDir)
	os.Chdir(ATTACHMENTS)
	exec.Command(FFMPEG_PATH, "-dump_attachment:t", "", "-i", fmt.Sprintf("../%s", name)).Run()
	fileInfoList, _ := ioutil.ReadDir(".")
	for _, fileInfo := range fileInfoList {
		link := fmt.Sprintf("%s\\%s", FONT_DIR, fileInfo.Name())
		target := fileInfo.Name()
		if err := exec.Command("cmd", "/c", "MKLINK", "/H", link, target).Run(); err != nil {
			fmt.Println(err)
		}
	}
	os.Chdir("..")
}

func encode(fileInfo os.FileInfo) {
	defer cleanup()

	name := fileInfo.Name()
	loc := strings.LastIndex(name, ".")

	if name[loc+1:] != EXTENSION {
		return
	}

	outputName := fmt.Sprintf("%s.mp4", name[:loc])
	installFonts(name)

	// Extract ASS subtitles
	exec.Command(FFMPEG_PATH, "-i", name, ASS).Run()

	// Encode Video
	cmd := exec.Command(FFMPEG_PATH, "-i", name,
		"-tune", "animation", "-preset", PRESET, "-profile:v", PROFILE, "-crf", CRF_VALUE,
		"-vf", fmt.Sprintf("ass=%s", ASS),
		"-c:v", "libx264",
		"-c:a", "copy",
		"-threads", "2",
		outputName)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.Run()
}

func handleInterrupt() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func() {
		for sig := range c {
			log.Printf("captured %v, stopping and exiting..", sig)
			cleanup()
			os.Exit(1)
		}
	}()
}

func main() {
	handleInterrupt()

	os.Setenv("FC_CONFIG_DIR", FC_CONFIG_DIR)
	os.Setenv("FC_CONFIG_FILE", FC_CONFIG_FILE)

	dir, err := os.Getwd()
	if err != nil {
		fmt.Println(err)
		return
	}

	fileInfoList, err := ioutil.ReadDir(dir)
	if err != nil {
		fmt.Println(err)
		return
	}

	for _, fileInfo := range fileInfoList {
		encode(fileInfo)
	}
}