Added IOException to WaveformData constructor

Change-Id: Ic00b582beaa2701ffa72e99194693fd7cfa45a6d

media/java/android/media/videoeditor/AudioTrack.java

@@ -450,7 +450,7 @@ public class AudioTrack {
     /**
      * @return The waveform data
      */
-    public WaveformData getWaveformData() {
+    public WaveformData getWaveformData() throws IOException {
         if (mWaveformData == null) {
             return null;
         }

media/java/android/media/videoeditor/MediaVideoItem.java

@@ -372,7 +372,7 @@ public class MediaVideoItem extends MediaItem {
     /**
      * @return The waveform data
      */
-    public WaveformData getWaveformData() {
+    public WaveformData getWaveformData() throws IOException {
         if (mWaveformData == null) {
             return null;
         }

media/java/android/media/videoeditor/TransitionAlpha.java

@@ -16,6 +16,9 @@
 
 package android.media.videoeditor;
 
+import java.io.File;
+
+
 
 /**
  * This class allows to render an "alpha blending" transition according to a
@@ -71,6 +74,7 @@ public class TransitionAlpha extends Transition {
      *           projects folder (the parent folder for all projects).
      * @param blendingPercent The blending percent applied
      * @param invert true to invert the direction of the alpha blending
+     *
      * @throws IllegalArgumentException if behavior is not supported, or if
      *             direction are not supported.
      */
@@ -79,6 +83,10 @@ public class TransitionAlpha extends Transition {
             int blendingPercent, boolean invert) {
         super(transitionId, afterMediaItem, beforeMediaItem, durationMs, behavior);
 
+        if (!new File(maskFilename).exists()) {
+            throw new IllegalArgumentException("Invalid mask file name: " + maskFilename);
+        }
+
         mMaskFilename = maskFilename;
         mBlendingPercent = blendingPercent;
         mIsInvert = invert;

media/java/android/media/videoeditor/WaveformData.java

@@ -46,7 +46,7 @@ public class WaveformData {
      *
      * @param audioWaveformFilename The name of the audio waveform file
      */
-    WaveformData(String audioWaveformFilename) {
+    WaveformData(String audioWaveformFilename) throws IOException {
         // TODO: Read these values from the file
         mFrameDurationMs = 20;
         mFramesCount = 300000 / mFrameDurationMs;