Merge "Fix for issue : 3419353 Crash during transition generation" into honeycomb

media/java/android/media/videoeditor/VideoEditorImpl.java

@@ -1566,6 +1566,7 @@ public class VideoEditorImpl implements VideoEditor {
         }
 
         boolean semAcquireDone = false;
+        if (!mPreviewInProgress) {
             try{
                 semAcquireDone = mMANativeHelper.lock(ENGINE_ACCESS_MAX_TIMEOUT_MS);
                 if (semAcquireDone == false) {
@@ -1573,11 +1574,11 @@ public class VideoEditorImpl implements VideoEditor {
                 }
 
                 if (mMediaItems.size() > 0) {
+                    mPreviewInProgress = true;
                     mMANativeHelper.previewStoryBoard(mMediaItems, mTransitions,
                                                       mAudioTracks, null);
                     mMANativeHelper.doPreview(surface, fromMs, toMs, loop,
                                      callbackAfterFrameCount, listener);
-                mPreviewInProgress = true;
                 }
                 /**
                  *  release on complete by calling stopPreview
@@ -1585,10 +1586,9 @@ public class VideoEditorImpl implements VideoEditor {
             } catch (InterruptedException ex) {
                 Log.w(TAG, "The thread was interrupted", new Throwable());
                 throw new IllegalStateException("The thread was interrupted");
-        } finally {
-            if (semAcquireDone) {
-                mMANativeHelper.unlock();
             }
+         } else {
+            throw new IllegalStateException("Preview already in progress");
         }
     }
 
@@ -1596,15 +1596,20 @@ public class VideoEditorImpl implements VideoEditor {
      * {@inheritDoc}
      */
     public long stopPreview() {
+        long result = 0;
         if (mPreviewInProgress) {
-            long result = mMANativeHelper.stopPreview();
+            try {
-            mPreviewInProgress = false;
+                result = mMANativeHelper.stopPreview();
                 /**
-             *  release the sem acquired in startPreview
+                 *  release on complete by calling stopPreview
                  */
+                } finally {
+                    mPreviewInProgress = false;
                     mMANativeHelper.unlock();
+                }
             return result;
-        } else {
+        }
+        else {
             return 0;
         }
     }