return Future and add error handling

Author: MaiKambayashi

example/src/main/java/net/ypresto/androidtranscoder/example/TranscoderActivity.java

@@ -21,12 +21,14 @@
 import java.io.FileDescriptor;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.concurrent.Future;
 
 
 public class TranscoderActivity extends Activity {
     private static final String TAG = "TranscoderActivity";
     private static final int REQUEST_CODE_PICK = 1;
     private static final int PROGRESS_BAR_MAX = 1000;
+    private Future mFuture;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -41,7 +43,7 @@ public void onClick(View v) {
         findViewById(R.id.cancel_button).setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
-                MediaTranscoder.getInstance().cancel();
+                mFuture.cancel(true);
             }
         });
     }
@@ -86,22 +88,22 @@ public void onTranscodeProgress(double progress) {
                         @Override
                         public void onTranscodeCompleted() {
                             Log.d(TAG, "transcoding took " + (SystemClock.uptimeMillis() - startTime) + "ms");
-                            transcodeFinishEvent(progressBar, PROGRESS_BAR_MAX, "transcoded file placed on " + file, parcelFileDescriptor);
+                            onTranscodeFinished(true, "transcoded file placed on " + file, parcelFileDescriptor);
                             startActivity(new Intent(Intent.ACTION_VIEW).setDataAndType(Uri.fromFile(file), "video/mp4"));
                         }
 
                         @Override
                         public void onTranscodeCanceled() {
-                            transcodeFinishEvent(progressBar, 0, "Transcoder canceled.", parcelFileDescriptor);
+                            onTranscodeFinished(false, "Transcoder canceled.", parcelFileDescriptor);
                         }
 
                         @Override
                         public void onTranscodeFailed(Exception exception) {
-                            transcodeFinishEvent(progressBar, 0, "Transcoder error occurred.", parcelFileDescriptor);
+                            onTranscodeFinished(false, "Transcoder error occurred.", parcelFileDescriptor);
                         }
                     };
                     Log.d(TAG, "transcoding into " + file);
-                    MediaTranscoder.getInstance().transcodeVideo(fileDescriptor, file.getAbsolutePath(),
+                    mFuture = MediaTranscoder.getInstance().transcodeVideo(fileDescriptor, file.getAbsolutePath(),
                             MediaFormatStrategyPresets.createAndroid720pStrategy(), listener);
                     switchButtonEnabled(true);
                 }
@@ -131,9 +133,10 @@ public boolean onOptionsItemSelected(MenuItem item) {
         return super.onOptionsItemSelected(item);
     }
 
-    private void transcodeFinishEvent(ProgressBar progressBar, int progress, String toastMessage, ParcelFileDescriptor parcelFileDescriptor) {
+    private void onTranscodeFinished(boolean isSuccess, String toastMessage, ParcelFileDescriptor parcelFileDescriptor) {
+        final ProgressBar progressBar = (ProgressBar) findViewById(R.id.progress_bar);
         progressBar.setIndeterminate(false);
-        progressBar.setProgress(progress);
+        progressBar.setProgress(isSuccess ? PROGRESS_BAR_MAX : 0);
         switchButtonEnabled(false);
         Toast.makeText(TranscoderActivity.this, toastMessage, Toast.LENGTH_LONG).show();
         try {

lib/src/main/java/net/ypresto/androidtranscoder/MediaTranscoder.java

@@ -27,21 +27,21 @@
 import java.io.FileDescriptor;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.util.concurrent.Callable;
 import java.util.concurrent.Future;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 
 public class MediaTranscoder {
     private static final String TAG = "MediaTranscoder";
     private static final int MAXIMUM_THREAD = 1; // TODO
     private static volatile MediaTranscoder sMediaTranscoder;
-    private Future mFuture;
     private ThreadPoolExecutor mExecutor;
 
     private MediaTranscoder() {
-        mFuture = null;
         mExecutor = new ThreadPoolExecutor(
                 0, MAXIMUM_THREAD, 60, TimeUnit.SECONDS,
                 new LinkedBlockingQueue<Runnable>(),
@@ -74,8 +74,8 @@ public static MediaTranscoder getInstance() {
      * @deprecated Use {@link #transcodeVideo(FileDescriptor, String, MediaFormatStrategy, MediaTranscoder.Listener)} which accepts output video format.
      */
     @Deprecated
-    public void transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final Listener listener) {
-        transcodeVideo(inFileDescriptor, outPath, new MediaFormatStrategy() {
+    public Future transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final Listener listener) {
+        return transcodeVideo(inFileDescriptor, outPath, new MediaFormatStrategy() {
             @Override
             public MediaFormat createVideoOutputFormat(MediaFormat inputFormat) {
                 return MediaFormatPresets.getExportPreset960x540();
@@ -98,7 +98,7 @@ public MediaFormat createAudioOutputFormat(MediaFormat inputFormat) {
      * @param listener          Listener instance for callback.
      * @throws IOException if input file could not be read.
      */
-    public void transcodeVideo(final String inPath, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) throws IOException {
+    public Future transcodeVideo(final String inPath, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) throws IOException {
         FileInputStream fileInputStream = null;
         FileDescriptor inFileDescriptor;
         try {
@@ -115,7 +115,7 @@ public void transcodeVideo(final String inPath, final String outPath, final Medi
             throw e;
         }
         final FileInputStream finalFileInputStream = fileInputStream;
-        transcodeVideo(inFileDescriptor, outPath, outFormatStrategy, new Listener() {
+        return transcodeVideo(inFileDescriptor, outPath, outFormatStrategy, new Listener() {
             @Override
             public void onTranscodeProgress(double progress) {
                 listener.onTranscodeProgress(progress);
@@ -158,13 +158,14 @@ private void closeStream() {
      * @param outFormatStrategy Strategy for output video format.
      * @param listener          Listener instance for callback.
      */
-    public void transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) {
+    public Future transcodeVideo(final FileDescriptor inFileDescriptor, final String outPath, final MediaFormatStrategy outFormatStrategy, final Listener listener) {
         Looper looper = Looper.myLooper();
         if (looper == null) looper = Looper.getMainLooper();
         final Handler handler = new Handler(looper);
-        mFuture = mExecutor.submit(new Runnable() {
+        final AtomicReference<Future> futureReference = new AtomicReference<>();
+        final Future<Void> createdFuture = mExecutor.submit(new Callable<Void>() {
             @Override
-            public void run() {
+            public Void call() throws Exception {
                 Exception caughtException = null;
                 try {
                     MediaTranscoderEngine engine = new MediaTranscoderEngine();
@@ -200,23 +201,22 @@ public void run() {
                         if (exception == null) {
                             listener.onTranscodeCompleted();
                         } else {
-                            if (exception instanceof InterruptedException) {
+                            Future future = futureReference.get();
+                            if (future != null && future.isCancelled()) {
                                 listener.onTranscodeCanceled();
                             } else {
                                 listener.onTranscodeFailed(exception);
                             }
                         }
                     }
                 });
+
+                if (exception != null) throw exception;
+                return null;
             }
         });
-    }
-
-    /**
-     * Cancel transcode video file
-     */
-    public boolean cancel() {
-        return mFuture != null ? mFuture.cancel(true) : false;
+        futureReference.set(createdFuture);
+        return createdFuture;
     }
 
     public interface Listener {

lib/src/main/java/net/ypresto/androidtranscoder/engine/MediaTranscoderEngine.java

@@ -78,6 +78,7 @@ public double getProgress() {
      * @param formatStrategy Output format strategy.
      * @throws IOException                  when input or output file could not be opened.
      * @throws InvalidOutputFormatException when output format is not supported.
+     * @throws InterruptedException         when cancel to transcode.
      */
     public void transcodeVideo(String outputPath, MediaFormatStrategy formatStrategy) throws IOException, InterruptedException {
         if (outputPath == null) {
@@ -95,8 +96,6 @@ public void transcodeVideo(String outputPath, MediaFormatStrategy formatStrategy
             setupTrackTranscoders(formatStrategy);
             runPipelines();
             mMuxer.stop();
-        } catch (InterruptedException e) {
-            throw e;
         } finally {
             try {
                 if (mVideoTrackTranscoder != null) {
@@ -181,7 +180,7 @@ public void onDetermineOutputFormat() {
         mExtractor.selectTrack(trackResult.mAudioTrackIndex);
     }
 
-    private void runPipelines() throws InterruptedException {
+    private void runPipelines() {
         long loopCount = 0;
         if (mDurationUs <= 0) {
             double progress = PROGRESS_UNKNOWN;
@@ -203,10 +202,9 @@ private void runPipelines() throws InterruptedException {
                 try {
                     Thread.sleep(SLEEP_TO_WAIT_TRACK_TRANSCODERS);
                 } catch (InterruptedException e) {
-                    throw e;
+                    // nothing to do
                 }
             }
-            if (Thread.interrupted()) throw new InterruptedException();
         }
     }