Created a Java w/ Maven project structure; added a simple directory creation and executes an FFMPEG command to transcode videos

src/main/java/tech/bitgoblin/App.java

@@ -0,0 +1,17 @@
+package tech.bitgoblin;
+
+import tech.bitgoblin.video.Transcoder;
+
+/**
+ * The Bit Goblin video transcoder service.
+ *
+ */
+public class App {
+
+  public static void main(String[] args) {
+    // create new Transcoder object and start the service
+    Transcoder t = new Transcoder("~/dragoon");
+    t.transcode();
+  }
+
+}

src/main/java/tech/bitgoblin/io/IOUtils.java

@@ -0,0 +1,27 @@
+package tech.bitgoblin.io;
+
+import java.io.File;
+
+public class IOUtils {
+
+  public static void createDirectory(String path) {
+    File f = new File(path);
+    boolean res = f.mkdir();
+
+    if (res) {
+      System.out.println(path + " was created.");
+    }
+  }
+
+  public static String resolveTilda(String path) {
+    if (path.startsWith("~" + File.separator)) {
+      path = System.getProperty("user.home") + path.substring(1);
+    } else if (path.startsWith("~")) {
+      // here you can implement reading homedir of other users if you care
+      throw new UnsupportedOperationException("Home dir expansion not implemented for explicit usernames");
+    }
+
+    return path;
+  }
+
+}

src/main/java/tech/bitgoblin/video/Transcoder.java

@@ -0,0 +1,102 @@
+package tech.bitgoblin.video;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.IOException;
+import java.lang.InterruptedException;
+import java.lang.Process;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.function.Consumer;
+import java.util.concurrent.Executors;
+
+import tech.bitgoblin.io.IOUtils;
+
+public class Transcoder {
+
+  private String repo_dir;
+  private String ffmpeg_path = "/usr/bin/ffmpeg";
+
+  // only define the working directory; use default FFMPEG path
+  public Transcoder(String repo_dir) {
+    this.repo_dir = IOUtils.resolveTilda(repo_dir);
+    this.initDirectory();
+  }
+  // define a custom FFMPEG binary path
+  public Transcoder(String repo_dir, String ffmpeg_path) {
+    this.repo_dir = IOUtils.resolveTilda(repo_dir);
+    this.ffmpeg_path = ffmpeg_path;
+    this.initDirectory();
+  }
+
+  // transcode files in the working directory
+  public void transcode() {
+    // search for files
+    System.out.println("Searching for files to transcode in " + this.repo_dir);
+    File repo = new File(Paths.get(this.repo_dir, "ingest").toString());
+    File[] sourceFiles = repo.listFiles();
+
+    // transcode
+    System.out.println("Transcoding files in " + this.repo_dir + "/ingest...");
+    for (File f : sourceFiles) {
+      String filePath = f.toString().substring(0, f.toString().lastIndexOf("."));
+      String filename = Paths.get(filePath).getFileName().toString();
+      String outputPath = Paths.get(this.repo_dir, "output", String.format("%s.mov", filename)).toString();
+
+      String cmd = String.format("%s -i %s -c:v %s -vf \"%s\" -profile:v %s -c:a %s %s",
+        this.ffmpeg_path, // FFMPEG binary path
+        f.toString(), // input file
+        "dnxhd", // video codec
+        "scale=1920x1080,fps=60,format=yuv422p", // video format
+        "dnxhr_hq", // video profile
+        "pcm_s16le", // audio codec
+        outputPath // output file path
+      );
+
+      ProcessBuilder pb = new ProcessBuilder(cmd.split("\\s+"));
+      pb.redirectErrorStream(true);
+      pb.redirectOutput(ProcessBuilder.Redirect.PIPE);
+      try {
+        Process process = pb.start();
+        int ret = process.waitFor();
+        System.out.printf("Program exited with code: %d", ret);
+      } catch (IOException | InterruptedException e) {
+        throw new RuntimeException(e);
+      }
+    }
+
+    // end output
+    System.out.println("------------ End of transcoding ------------");
+    System.out.println();
+  }
+
+  // ensures the transcoder's working directory is available
+  private void initDirectory() {
+    // create transcoder directory
+    IOUtils.createDirectory(this.repo_dir);
+    // create the sub-directories
+    IOUtils.createDirectory(Paths.get(this.repo_dir, "ingest").toString());
+    IOUtils.createDirectory(Paths.get(this.repo_dir, "archive").toString());
+    IOUtils.createDirectory(Paths.get(this.repo_dir, "output").toString());
+  }
+
+
+  // Stream handler class for the Transcoder
+  private static class StreamGobbler implements Runnable {
+    private InputStream inputStream;
+    private Consumer<String> consumer;
+
+    public StreamGobbler(InputStream inputStream, Consumer<String> consumer) {
+        this.inputStream = inputStream;
+        this.consumer = consumer;
+    }
+
+    @Override
+    public void run() {
+      new BufferedReader(new InputStreamReader(inputStream)).lines().forEach(consumer);
+    }
+  }
+
+}