Add pixel comparison to FrameExtractorTest

Add PSNR comparison with the output of MedaiMetadataRetriever.

PiperOrigin-RevId: 696190585

libraries/transformer/src/androidTest/java/androidx/media3/transformer/FrameExtractorTest.java

@@ -17,6 +17,8 @@ package androidx.media3.transformer;
 
 import static androidx.media3.common.PlaybackException.ERROR_CODE_IO_FILE_NOT_FOUND;
 import static androidx.media3.test.utils.BitmapPixelTestUtil.maybeSaveTestBitmap;
+import static androidx.media3.test.utils.BitmapPixelTestUtil.readBitmap;
+import static androidx.media3.test.utils.TestUtil.assertBitmapsAreSimilar;
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
 import static java.util.concurrent.TimeUnit.SECONDS;
@@ -33,9 +35,13 @@ import androidx.media3.transformer.ExperimentalFrameExtractor.Frame;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.platform.app.InstrumentationRegistry;
+import com.google.common.collect.ImmutableList;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.atomic.AtomicReference;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@@ -49,9 +55,15 @@ import org.junit.runner.RunWith;
 /** End-to-end instrumentation test for {@link ExperimentalFrameExtractor}. */
 @RunWith(AndroidJUnit4.class)
 public class FrameExtractorTest {
+  // Golden files are generated by MediaMetadataRetriever running on Pixel 8.
+  private static final String GOLDEN_ASSET_FOLDER_PATH =
+      "test-generated-goldens/FrameExtractorTest/";
   private static final String FILE_PATH =
       "asset:///media/mp4/sample_with_increasing_timestamps_360p.mp4";
   private static final long TIMEOUT_SECONDS = 10;
+  // TODO: b/350498258 - Due to bugs in hardware decoders, we can only assert for low PSNR values.
+  // Move to using software decoders in pixel tests, and increase PSNR threshold.
+  private static final float PSNR_THRESHOLD = 25f;
 
   @Rule public final TestName testName = new TestName();
 
@@ -77,15 +89,16 @@ public class FrameExtractorTest {
     frameExtractor = new ExperimentalFrameExtractor(context, MediaItem.fromUri(FILE_PATH));
 
     ListenableFuture<Frame> frameFuture = frameExtractor.getFrame(/* positionMs= */ 8_500);
-    Bitmap bitmap = frameFuture.get(TIMEOUT_SECONDS, SECONDS).bitmap;
+    Frame frame = frameFuture.get(TIMEOUT_SECONDS, SECONDS);
+    Bitmap actualBitmap = frame.bitmap;
+    Bitmap expectedBitmap =
+        readBitmap(
+            /* assetString= */ GOLDEN_ASSET_FOLDER_PATH
+                + "sample_with_increasing_timestamps_360p_8.531.png");
+    maybeSaveTestBitmap(testId, /* bitmapLabel= */ "actual", actualBitmap, /* path= */ null);
 
-    maybeSaveTestBitmap(testId, /* bitmapLabel= */ "actual", bitmap, /* path= */ null);
-    assertThat(frameFuture.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(8_531);
-    // TODO: b/350498258 - Actually check Bitmap contents. Due to bugs in hardware decoders,
-    //   such a test would require a too high tolerance.
-    assertThat(bitmap.getWidth()).isEqualTo(640);
-    assertThat(bitmap.getHeight()).isEqualTo(360);
-    assertThat(bitmap.getConfig()).isEqualTo(Bitmap.Config.ARGB_8888);
+    assertThat(frame.presentationTimeMs).isEqualTo(8_531);
+    assertBitmapsAreSimilar(expectedBitmap, actualBitmap, PSNR_THRESHOLD);
   }
 
   @Test
@@ -93,27 +106,43 @@ public class FrameExtractorTest {
     frameExtractor = new ExperimentalFrameExtractor(context, MediaItem.fromUri(FILE_PATH));
 
     ListenableFuture<Frame> frameFuture = frameExtractor.getFrame(/* positionMs= */ 200_000);
+    Frame frame = frameFuture.get(TIMEOUT_SECONDS, SECONDS);
+    Bitmap actualBitmap = frame.bitmap;
     int lastVideoFramePresentationTimeMs = 17_029;
+    Bitmap expectedBitmap =
+        readBitmap(
+            /* assetString= */ GOLDEN_ASSET_FOLDER_PATH
+                + "sample_with_increasing_timestamps_360p_17.029.png");
+    maybeSaveTestBitmap(testId, /* bitmapLabel= */ "actual", actualBitmap, /* path= */ null);
 
-    assertThat(frameFuture.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs)
-        .isEqualTo(lastVideoFramePresentationTimeMs);
+    assertThat(frame.presentationTimeMs).isEqualTo(lastVideoFramePresentationTimeMs);
+    assertBitmapsAreSimilar(expectedBitmap, actualBitmap, PSNR_THRESHOLD);
   }
 
   @Test
   public void extractFrame_repeatedPositionMs_returnsTheSameFrame() throws Exception {
     frameExtractor = new ExperimentalFrameExtractor(context, MediaItem.fromUri(FILE_PATH));
+    ImmutableList<Long> requestedFramePositionsMs = ImmutableList.of(0L, 0L, 33L, 34L, 34L);
+    ImmutableList<Long> expectedFramePositionsMs = ImmutableList.of(0L, 0L, 33L, 66L, 66L);
+    List<ListenableFuture<Frame>> frameFutures = new ArrayList<>();
 
-    ListenableFuture<Frame> frame0 = frameExtractor.getFrame(/* positionMs= */ 0);
-    ListenableFuture<Frame> frame0Again = frameExtractor.getFrame(/* positionMs= */ 0);
-    ListenableFuture<Frame> frame33 = frameExtractor.getFrame(/* positionMs= */ 33);
-    ListenableFuture<Frame> frame34 = frameExtractor.getFrame(/* positionMs= */ 34);
-    ListenableFuture<Frame> frame34Again = frameExtractor.getFrame(/* positionMs= */ 34);
+    for (long positionMs : requestedFramePositionsMs) {
+      frameFutures.add(frameExtractor.getFrame(positionMs));
+    }
+    for (int i = 0; i < expectedFramePositionsMs.size(); i++) {
+      ListenableFuture<Frame> frameListenableFuture = frameFutures.get(i);
+      Frame frame = frameListenableFuture.get(TIMEOUT_SECONDS, SECONDS);
+      maybeSaveTestBitmap(testId, /* bitmapLabel= */ "actual_" + i, frame.bitmap, /* path= */ null);
+      Bitmap expectedBitmap =
+          readBitmap(
+              /* assetString= */ GOLDEN_ASSET_FOLDER_PATH
+                  + "sample_with_increasing_timestamps_360p_"
+                  + String.format(Locale.US, "%.3f", frame.presentationTimeMs / 1000f)
+                  + ".png");
 
-    assertThat(frame0.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(0);
-    assertThat(frame0Again.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(0);
-    assertThat(frame33.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(33);
-    assertThat(frame34.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(66);
-    assertThat(frame34Again.get(TIMEOUT_SECONDS, SECONDS).presentationTimeMs).isEqualTo(66);
+      assertBitmapsAreSimilar(expectedBitmap, frame.bitmap, PSNR_THRESHOLD);
+      assertThat(frame.presentationTimeMs).isEqualTo(expectedFramePositionsMs.get(i));
+    }
   }
 
   @Test