Handle content-generation failures better

If we somehow got a software codec -- maybe we're on an emulator --
the creation of the generated videos would fail.  This killed the
app shortly after it started, leaving an obscure failure in the
log file.

We now trap the failure and put up an exception dialog warning
that not all features may be available.  If it looks like we're
trying to use the software AVC codec, we make that explicit in
the error dialog.

Author: fadden

AndroidManifest.xml

@@ -17,7 +17,7 @@
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.grafika"
-    android:versionCode="21"
+    android:versionCode="22"
     android:versionName="1.0" >
 
     <uses-sdk

README.md

@@ -41,11 +41,14 @@ There are two areas where some amount of care is taken:
 
 All code is written in the Java programming language -- the NDK is not used.
 
+The first time Grafika starts, two videos are generated (gen-eight-rects, gen-sliders).
+If you want to experiment with the generation code, you can cause them to be re-generated
+from the main activity menu ("Regenerate content").
+
 Some features of Grafika may not work on an emulator, notably anything that involves
 encoding video.  The problem is that the software AVC encoder doesn't support
 `createInputSurface()`, and all of Grafika's video encoding features currently make
-use of that.  \[Grafika currently crashes on startup when it tries to generate a
-couple of videos; this will be fixed.]
+use of that.  Very little works in the AOSP emulator, even with `-gpu on`.
 
 
 Current features
@@ -72,6 +75,7 @@ Current features
   usually matches what the camera provides.
 
 [Double decode](src/com/android/grafika/DoubleDecodeActivity.java).  Decodes two video streams side-by-side to a pair of `TextureViews`.
+- Plays the two auto-generated videos.  Note they play at different rates.
 - The video decoders don't stop when the screen is rotated.  We retain the `SurfaceTexture`
   and just attach it to the new `TextureView`.  Useful for avoiding expensive codec reconfigures.
   The decoders *do* stop if you leave the activity, so we don't tie up hardware codec
@@ -145,11 +149,6 @@ Feature & fix ideas
 
 In no particular order.
 
-- Try to detect when the codec selects a software AVC codec, as the current SoftAVC
-  codec does not work with input surfaces.
-- If initial movie generation fails, handle it better (currently crashes -- should
-  show a dialog explaining what happened).  This currently prevents Grafika from
-  working at all on emulators.
 - Add a trivial glTexImage2D texture upload speed benchmark (maybe 512x512 RGBA).
 - Update MoviePlayer#doExtract() to improve startup latency
   (http://stackoverflow.com/questions/21440820/).

res/values/strings.xml

@@ -28,6 +28,9 @@
     <string name="about_text">\nA random assortment of graphics and media hacks.\n\n
         [This is a perpetual work in progress.]\n\n
         Copyright 2013-2014 Google Inc.  All rights reserved.</string>
+    <string name="content_generation_failed_title">Unable to generate content</string>
+    <string name="content_generation_failed_msg">Failed to generate content.  Some
+         features may be unavailable.\n\n%1$s</string>
     <string name="ok">OK</string>
     <string name="cancel">Cancel</string>
     <string name="save">Save</string>

src/com/android/grafika/ContentManager.java

@@ -19,6 +19,7 @@
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.os.AsyncTask;
 import android.util.Log;
 import android.widget.ProgressBar;
@@ -88,7 +89,7 @@ public static void initialize(Context context) {
      * <p>
      * If this returns false, call createAll.
      */
-    public boolean isContentCreated(Context unused) {
+    public boolean isContentCreated(@SuppressWarnings("unused") Context unused) {
         // Ideally this would probe each individual item to see if anything needs to be done,
         // and a subsequent "prepare" call would generate only the necessary items.  This
         // takes a much simpler approach and just checks to see if the files exist.  If the
@@ -117,7 +118,8 @@ public void createAll(Activity caller) {
      * Prepares the specified content.  For example, if the caller requires a movie that doesn't
      * exist, this will post a progress dialog and generate the movie.
      * <p>
-     * Call from main UI thread.
+     * Call from main UI thread.  This returns immediately.  Content generation continues
+     * on a background thread.
      */
     public void prepareContent(Activity caller, int[] tags) {
         // Put up the progress dialog.
@@ -126,7 +128,7 @@ public void prepareContent(Activity caller, int[] tags) {
         AlertDialog dialog = builder.show();
 
         // Generate content in async task.
-        GenerateTask genTask = new GenerateTask(dialog, tags);
+        GenerateTask genTask = new GenerateTask(caller, dialog, tags);
         genTask.execute();
     }
 
@@ -201,6 +203,7 @@ public interface ProgressUpdater {
     private static class GenerateTask extends AsyncTask<Void, Integer, Integer>
             implements ProgressUpdater {
         // ----- accessed from UI thread -----
+        private final Context mContext;
         private final AlertDialog mPrepDialog;
         private final ProgressBar mProgressBar;
 
@@ -209,9 +212,11 @@ private static class GenerateTask extends AsyncTask<Void, Integer, Integer>
 
         // ----- accessed from both -----
         private final int[] mTags;
+        private volatile RuntimeException mFailure;
 
 
-        public GenerateTask(AlertDialog dialog, int[] tags) {
+        public GenerateTask(Context context, AlertDialog dialog, int[] tags) {
+            mContext = context;
             mPrepDialog = dialog;
             mTags = tags;
             mProgressBar = (ProgressBar) mPrepDialog.findViewById(R.id.work_progress);
@@ -226,10 +231,20 @@ protected Integer doInBackground(Void... params) {
             for (int i = 0; i < mTags.length; i++) {
                 mCurrentIndex = i;
                 updateProgress(0);
-                contentManager.prepare(this, mTags[i]);
+                try {
+                    contentManager.prepare(this, mTags[i]);
+                } catch (RuntimeException re) {
+                    mFailure = re;
+                    break;
+                }
                 updateProgress(100);
             }
-            Log.d(TAG, "done");
+
+            if (mFailure != null) {
+                Log.w(TAG, "Failed while generating content", mFailure);
+            } else {
+                Log.d(TAG, "generation complete");
+            }
             return 0;
         }
 
@@ -254,6 +269,30 @@ protected void onProgressUpdate(Integer... progressArray) {
         protected void onPostExecute(Integer result) {
             Log.d(TAG, "onPostExecute -- dismss");
             mPrepDialog.dismiss();
+
+            if (mFailure != null) {
+                showFailureDialog(mContext, mFailure);
+            }
+        }
+
+        /**
+         * Posts an error dialog, including the message from the failure exception.
+         */
+        private void showFailureDialog(Context context, RuntimeException failure) {
+            AlertDialog.Builder builder = new AlertDialog.Builder(context);
+            builder.setTitle(R.string.content_generation_failed_title);
+            String msg = context.getString(R.string.content_generation_failed_msg,
+                    failure.getMessage());
+            builder.setMessage(msg);
+            builder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(DialogInterface dialog, int id) {
+                    dialog.dismiss();
+                }
+            });
+            builder.setCancelable(false);
+            AlertDialog dialog = builder.create();
+            dialog.show();
         }
     }
 }

src/com/android/grafika/GeneratedMovie.java

@@ -21,6 +21,7 @@
 import android.media.MediaFormat;
 import android.media.MediaMuxer;
 import android.util.Log;
+import android.view.Surface;
 
 import com.android.grafika.gles.EglCore;
 import com.android.grafika.gles.WindowSurface;
@@ -56,6 +57,15 @@ public abstract class GeneratedMovie implements Content {
      */
     public abstract void create(File outputFile, ContentManager.ProgressUpdater prog);
 
+    /**
+     * Returns true if the codec has a software implementation.
+     */
+    private static boolean isSoftwareCodec(MediaCodec codec) {
+        String codecName = codec.getCodecInfo().getName();
+
+        return ("OMX.google.h264.encoder".equals(codecName));
+    }
+
     /**
      * Prepares the video encoder, muxer, and an EGL input surface.
      */
@@ -78,8 +88,24 @@ protected void prepareEncoder(String mimeType, int width, int height, int bitRat
         // we can use for input and wrap it with a class that handles the EGL work.
         mEncoder = MediaCodec.createEncoderByType(mimeType);
         mEncoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
+        Log.v(TAG, "encoder is " + mEncoder.getCodecInfo().getName());
+        Surface surface;
+        try {
+            surface = mEncoder.createInputSurface();
+        } catch (IllegalStateException ise) {
+            // This is generally the first time we ever try to encode something through a
+            // Surface, so specialize the message a bit if we can guess at why it's failing.
+            // TODO: failure message should come out of strings.xml for i18n
+            if (isSoftwareCodec(mEncoder)) {
+                throw new RuntimeException("Can't use input surface with software codec: " +
+                        mEncoder.getCodecInfo().getName(),
+                        ise);
+            } else {
+                throw new RuntimeException("Failed to create input surface", ise);
+            }
+        }
         mEglCore = new EglCore(null, EglCore.FLAG_RECORDABLE);
-        mInputSurface = new WindowSurface(mEglCore, mEncoder.createInputSurface(), true);
+        mInputSurface = new WindowSurface(mEglCore, surface, true);
         mInputSurface.makeCurrent();
         mEncoder.start();