adept/transcoder/transcoder.go

package transcoder

import (
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"github.com/spf13/viper"

	"git.metaunix.net/BitGoblin/adept/util"
)

type Transcoder struct {
	repo Repository
}

// Transcoder object constructor
func NewTranscoder(r Repository) *Transcoder {
	t := new(Transcoder)
	t.repo = r
	return t
}

// Start the main transcoder loop
func (t *Transcoder) Start() {
	// main program loop - runs infinitely until externally terminated
  for {
    ingestFiles := t.repo.SearchIngest()

    if len(ingestFiles) < 1 {
      log.Println("There were no files found in ingest to transcode; skipping run.")
    } else {
      for _, i := range ingestFiles {
        // check if the file is open in another program (e.g. still being written to)
        if util.IsFileLocked(filepath.Join(t.repo.GetIngestPath(), i.Name())) {
          log.Printf("%s appears to be open in another program; skipping it for this run.", i.Name())
          continue
        }

        // archive file
        t.repo.ArchiveFile(i.Name())
        // transcode file
        t.Transcode(i.Name())
        // clean up source file
        t.repo.CleanupFile(i.Name())
      }
    }

    // sleep for X minutes - specified in the adept.toml config file
    interval := viper.GetInt("transcoder.interval")
    time.Sleep(time.Duration(interval) * time.Minute)
  }
}

func (t *Transcoder) Transcode(inFile string) {
	// create ingest and archive paths
  ingestPath := filepath.Join(t.repo.GetIngestPath(), inFile)
	outputName := strings.Join([]string{util.FilenameWithoutExtension(inFile), viper.GetString("transcoder.video_format")}, ".")
  outputPath := filepath.Join(t.repo.GetOutputPath(), outputName)

  log.Printf("Transcoding video file %s.", ingestPath)

	cmd := exec.Command("/usr/bin/ffmpeg", 
		"-i", ingestPath, 
		"-y",
		"-f", viper.GetString("transcoder.video_format"),
    "-c:v", viper.GetString("transcoder.video_codec"),
    "-s", viper.GetString("transcoder.video_resolution"),
    "-r", viper.GetString("transcoder.video_framerate"),
    "-vf", fmt.Sprintf("format=%s", viper.GetString("transcoder.video_color")),
    "-profile:v", viper.GetString("transcoder.video_profile"),
    "-c:a", viper.GetString("transcoder.audio_codec"),
    outputPath)

  if err := cmd.Run(); err != nil {
		log.Fatalf("Error while transcoding: %s.", err)
    os.Exit(1)
	}
}