Implement Aspect ratio preservation in GStreamerSurfaceView. Fix some corner cases that this triggers in the surface size reporting code.

gst-sdk/tutorials/android-tutorial-3/jni/tutorial-3.c

@@ -304,13 +304,21 @@ static jboolean gst_native_class_init (JNIEnv* env, jclass klass) {
 static void gst_native_surface_init (JNIEnv *env, jobject thiz, jobject surface) {
   CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
   if (!data) return;
-  GST_DEBUG ("Received surface %p", surface);
+  ANativeWindow *new_native_window = ANativeWindow_fromSurface(env, surface);
+  GST_DEBUG ("Received surface %p (native window %p)", surface, new_native_window);
+
   if (data->native_window) {
-    GST_DEBUG ("Releasing previous native window %p", data->native_window);
     ANativeWindow_release (data->native_window);
+    if (data->native_window == new_native_window) {
+      GST_DEBUG ("New native window is the same as the previous one", data->native_window);
+      if (data->video_sink)
+        gst_x_overlay_expose(GST_X_OVERLAY (data->video_sink));
+      return;
+    } else {
+      GST_DEBUG ("Released previous native window %p", data->native_window);
+    }
   }
-  data->native_window = ANativeWindow_fromSurface(env, surface);
-  GST_DEBUG ("Got Native Window %p", data->native_window);
+  data->native_window = new_native_window;
 
   if (data->video_sink) {
     GST_DEBUG ("Pipeline already created, notifying it about the native window.");

gst-sdk/tutorials/android-tutorial-3/res/layout/main.xml

@@ -15,6 +15,7 @@
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
+        android:layout_marginBottom="16dip"
         android:gravity="center_horizontal"
         android:orientation="horizontal" >
 
@@ -37,8 +38,8 @@
 
     <com.gst_sdk_tutorials.tutorial_3.GStreamerSurfaceView
         android:id="@+id/surface_video"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
         android:layout_gravity="center_vertical|center_horizontal" />
 
 </LinearLayout>

gst-sdk/tutorials/android-tutorial-3/src/com/gst_sdk_tutorials/tutorial_3/GStreamerSurfaceView.java

@@ -2,13 +2,14 @@ package com.gst_sdk_tutorials.tutorial_3;
 
 import android.content.Context;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.view.SurfaceView;
 import android.view.View;
 
 // A simple SurfaceView whose width and height is set from the outside
 public class GStreamerSurfaceView extends SurfaceView {
-    public int media_width = 320;  // Default values, only really meaningful for the layout editor in Eclipse
-    public int media_height = 200;
+    public int media_width = 100;  // Default values, only really meaningful for the layout editor in Eclipse
+    public int media_height = 100;
 
     // Mandatory constructors, they do not do much
     public GStreamerSurfaceView(Context context, AttributeSet attrs,
@@ -29,11 +30,10 @@ public class GStreamerSurfaceView extends SurfaceView {
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         int width = 0, height = 0;
 
+        Log.i ("GStreamer", "onMeasure called with " + media_width + "x" + media_height);
         // Obey width rules
         switch (View.MeasureSpec.getMode(widthMeasureSpec)) {
         case View.MeasureSpec.AT_MOST:
-            width = Math.min (View.MeasureSpec.getSize(widthMeasureSpec), media_width);
-            break;
         case View.MeasureSpec.EXACTLY:
             width = View.MeasureSpec.getSize(widthMeasureSpec);
             break;
@@ -44,8 +44,6 @@ public class GStreamerSurfaceView extends SurfaceView {
         // Obey height rules
         switch (View.MeasureSpec.getMode(heightMeasureSpec)) {
         case View.MeasureSpec.AT_MOST:
-            height = Math.min (View.MeasureSpec.getSize(heightMeasureSpec), media_height);
-            break;
         case View.MeasureSpec.EXACTLY:
             height = View.MeasureSpec.getSize(heightMeasureSpec);
             break;
@@ -53,6 +51,19 @@ public class GStreamerSurfaceView extends SurfaceView {
             height = media_height;
         }
 
+        // Preserve aspect ratio if we are allowed freedom in both axes
+        // FIXME: Implement the case where only one axis is free
+        if (View.MeasureSpec.getMode(heightMeasureSpec) == View.MeasureSpec.AT_MOST &&
+            View.MeasureSpec.getMode(widthMeasureSpec) == View.MeasureSpec.AT_MOST) {
+            int correct_height = width * media_height / media_width;
+            int correct_width = height * media_width / media_height;
+
+            if (correct_height < height)
+                height = correct_height;
+            else
+                width = correct_width;
+        }
+
         // Obey minimum size
         width = Math.max (getSuggestedMinimumWidth(), width);
         height = Math.max (getSuggestedMinimumHeight(), height);

gst-sdk/tutorials/android-tutorial-3/src/com/gst_sdk_tutorials/tutorial_3/Tutorial3.java

@@ -120,9 +120,14 @@ public class Tutorial3 extends Activity implements SurfaceHolder.Callback {
 
     private void onMediaSizeChanged (int width, int height) {
         Log.i ("GStreamer", "Media size changed to " + width + "x" + height);
-        GStreamerSurfaceView gsv = (GStreamerSurfaceView) this.findViewById(R.id.surface_video);
+        final GStreamerSurfaceView gsv = (GStreamerSurfaceView) this.findViewById(R.id.surface_video);
         gsv.media_width = width;
         gsv.media_height = height;
+        runOnUiThread(new Runnable() {
+            public void run() {
+                gsv.requestLayout();
+            }
+        });
     }
 
     static {