Android video rendering: Apply SurfaceTexture.getTransformationMatrix()

talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java

Index: talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java
diff --git a/talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java b/talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java
index 28c0f283c3909af15d9af73324ee4807c4c97b1d..e9391c7de629d15483f02adc37ff26ba4aa1b2f1 100644
--- a/talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java
+++ b/talk/app/webrtc/androidtests/src/org/webrtc/RendererCommonTest.java
@@ -35,7 +35,8 @@ import android.graphics.Point;
 
 import static org.webrtc.RendererCommon.ScalingType.*;
 import static org.webrtc.RendererCommon.getDisplaySize;
-import static org.webrtc.RendererCommon.getTextureMatrix;
+import static org.webrtc.RendererCommon.getLayoutMatrix;
+import static org.webrtc.RendererCommon.getSamplingMatrix;
 
 public class RendererCommonTest extends ActivityTestCase {
   @SmallTest
@@ -101,63 +102,69 @@ public class RendererCommonTest extends ActivityTestCase {
   }
 
   @SmallTest
-  static public void testTexMatrixDefault() {
-    final float texMatrix[] = new float[16];
-    getTextureMatrix(texMatrix, 0, false, 1.0f, 1.0f);
-    // TODO(magjed): Every tex matrix contains a vertical flip, because we ignore the texture
-    // transform matrix from the SurfaceTexture (which contains a vertical flip). Update tests when
-    // this is fixed.
+  static public void testLayoutMatrixDefault() {
+    final float layoutMatrix[] = getLayoutMatrix(false, 1.0f, 1.0f);
     // Assert:
     // u' = u.
-    // v' = 1 - v.
-    MoreAsserts.assertEquals(round(texMatrix), new double[]
+    // v' = v.
+    MoreAsserts.assertEquals(round(layoutMatrix), new double[]
         {1, 0, 0, 0,
-         0, -1, 0, 0,
+         0, 1, 0, 0,
          0, 0, 1, 0,
-         0, 1, 0, 1});
+         0, 0, 0, 1});
   }
 
   @SmallTest
-  static public void testTexMatrixMirror() {
-    final float texMatrix[] = new float[16];
-    getTextureMatrix(texMatrix, 0, true, 1.0f, 1.0f);
+  static public void testLayoutMatrixMirror() {
+    final float layoutMatrix[] = getLayoutMatrix(true, 1.0f, 1.0f);
     // Assert:
     // u' = 1 - u.
-    // v' = 1 - v.
-    MoreAsserts.assertEquals(round(texMatrix), new double[]
+    // v' = v.
+    MoreAsserts.assertEquals(round(layoutMatrix), new double[]
         {-1, 0, 0, 0,
-         0, -1, 0, 0,
-         0, 0, 1, 0,
-         1, 1, 0, 1});
+          0, 1, 0, 0,
+          0, 0, 1, 0,
+          1, 0, 0, 1});

[hbos, 2015/09/08 14:08:47]

I don't fully understand the matrix values in these unittests, like why the "1"
in the bottom-left corner? Just me being bad at transformation matrix math. Can
you briefly explain offline?

[magjed_webrtc, 2015/09/08 15:24:28]

Done. Also added comment.

[hbos, 2015/09/09 08:27:54]

Acknowledged.

   }
 
   @SmallTest
-  static public void testTexMatrixRotation90Deg() {
-    final float texMatrix[] = new float[16];
-    getTextureMatrix(texMatrix, 90, false, 1.0f, 1.0f);
+  static public void testLayoutMatrixScale() {
+    // Video has aspect ratio 2, but layout is square. This will cause only the center part of the
+    // video to be visible, i.e. the u coordinate will go from 0.25 to 0.75 instead of from 0 to 1.
+    final float layoutMatrix[] = getLayoutMatrix(false, 2.0f, 1.0f);
     // Assert:
-    // u' = 1 - v.
-    // v' = 1 - u.
-    MoreAsserts.assertEquals(round(texMatrix), new double[]
-        {0, -1, 0, 0,
-         -1, 0, 0, 0,
-         0, 0, 1, 0,
-         1, 1, 0, 1});
+    // u' = 0.25 + 0.5 u.
+    // v' = v.
+    MoreAsserts.assertEquals(round(layoutMatrix), new double[]
+        { 0.5, 0, 0, 0,
+            0, 1, 0, 0,
+            0, 0, 1, 0,
+         0.25, 0, 0, 1});
   }
 
   @SmallTest
-  static public void testTexMatrixScale() {
-    final float texMatrix[] = new float[16];
-    // Video has aspect ratio 2, but layout is square. This will cause only the center part of the
-    // video to be visible, i.e. the u coordinate will go from 0.25 to 0.75 instead of from 0 to 1.
-    getTextureMatrix(texMatrix, 0, false, 2.0f, 1.0f);
+  static public void testSamplingMatrixDefault() {
+    final float samplingMatrix[] = getSamplingMatrix(null, 0);
     // Assert:
-    // u' = 0.25 + 0.5 u.
+    // u' = u.
     // v' = 1 - v.
-    MoreAsserts.assertEquals(round(texMatrix), new double[]
-        {0.5, 0, 0, 0,
+    MoreAsserts.assertEquals(round(samplingMatrix), new double[]
+        {1,  0, 0, 0,
          0, -1, 0, 0,
-         0, 0, 1, 0,
-         0.25, 1, 0, 1});
+         0,  0, 1, 0,
+         0,  1, 0, 1});
+  }
+
+  @SmallTest
+  static public void testSamplingMatrixRotation90Deg() {
+    final float samplingMatrix[] = getSamplingMatrix(null, 90);
+    // Assert:
+    // u' = 1 - u.
+    // v' = 1 - v.
+    MoreAsserts.assertEquals(round(samplingMatrix), new double[]
+        { 0, -1, 0, 0,
+         -1,  0, 0, 0,
+          0,  0, 1, 0,
+          1,  1, 0, 1});
   }
 }