Avoid re-encoding if video effects are no-op

This is to avoid regressions introduced by removing the convenience
methods from TransformationRequest.

PiperOrigin-RevId: 502864512

libraries/effect/src/main/java/androidx/media3/effect/ScaleToFitTransformation.java

@@ -92,6 +92,13 @@ public final class ScaleToFitTransformation implements MatrixTransformation {
     }
   }
 
+  /** The multiplier by which the frame will scale horizontally, along the x-axis. */
+  public final float scaleX;
+  /** The multiplier by which the frame will scale vertically, along the y-axis. */
+  public final float scaleY;
+  /** How much to rotate the frame counterclockwise, in degrees. */
+  public final float rotationDegrees;
+
   private final Matrix transformationMatrix;
   private @MonotonicNonNull Matrix adjustedTransformationMatrix;
 
@@ -103,6 +110,9 @@ public final class ScaleToFitTransformation implements MatrixTransformation {
    * @param rotationDegrees How much to rotate the frame counterclockwise, in degrees.
    */
   private ScaleToFitTransformation(float scaleX, float scaleY, float rotationDegrees) {
+    this.scaleX = scaleX;
+    this.scaleY = scaleY;
+    this.rotationDegrees = rotationDegrees;
     transformationMatrix = new Matrix();
     transformationMatrix.postScale(scaleX, scaleY);
     transformationMatrix.postRotate(rotationDegrees);

libraries/transformer/src/main/java/androidx/media3/transformer/TransformerInternal.java

@@ -43,6 +43,9 @@ import androidx.media3.common.audio.AudioProcessor;
 import androidx.media3.common.util.Clock;
 import androidx.media3.common.util.ConditionVariable;
 import androidx.media3.common.util.HandlerWrapper;
+import androidx.media3.common.util.Size;
+import androidx.media3.effect.Presentation;
+import androidx.media3.effect.ScaleToFitTransformation;
 import androidx.media3.extractor.metadata.mp4.SlowMotionData;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -577,16 +580,34 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
       if (inputFormat.pixelWidthHeightRatio != 1f) {
         return true;
       }
-      // The decoder rotates encoded frames for display by inputFormat.rotationDegrees.
+
-      int decodedHeight =
+      // TODO(b/265927935): consider generalizing this logic.
-          (inputFormat.rotationDegrees % 180 == 0) ? inputFormat.height : inputFormat.width;
+      for (int i = 0; i < videoEffects.size(); i++) {
-      if (transformationRequest.outputHeight != C.LENGTH_UNSET
+        Effect videoEffect = videoEffects.get(i);
-          && transformationRequest.outputHeight != decodedHeight) {
+        if (videoEffect instanceof Presentation) {
-        return true;
+          Presentation presentation = (Presentation) videoEffect;
-      }
+          // The decoder rotates encoded frames for display by inputFormat.rotationDegrees.
-      if (!videoEffects.isEmpty()) {
+          int decodedWidth =
-        return true;
+              (inputFormat.rotationDegrees % 180 == 0) ? inputFormat.width : inputFormat.height;
+          int decodedHeight =
+              (inputFormat.rotationDegrees % 180 == 0) ? inputFormat.height : inputFormat.width;
+          Size outputSize = presentation.configure(decodedWidth, decodedHeight);
+          if (outputSize.getWidth() != decodedWidth || outputSize.getHeight() != decodedHeight) {
+            return true;
+          }
+        } else if (videoEffect instanceof ScaleToFitTransformation) {
+          ScaleToFitTransformation scaleToFitTransformation =
+              (ScaleToFitTransformation) videoEffect;
+          if (scaleToFitTransformation.scaleX != 1f
+              || scaleToFitTransformation.scaleY != 1f
+              || scaleToFitTransformation.rotationDegrees != 0f) {
+            return true;
+          }
+        } else {
+          return true;
+        }
       }
+
       return false;
     }
   }

libraries/transformer/src/test/java/androidx/media3/transformer/TransformerEndToEndTest.java

@@ -43,11 +43,14 @@ import android.os.ParcelFileDescriptor;
 import android.view.Surface;
 import androidx.annotation.Nullable;
 import androidx.media3.common.C;
+import androidx.media3.common.Effect;
 import androidx.media3.common.Format;
 import androidx.media3.common.MediaItem;
 import androidx.media3.common.MimeTypes;
 import androidx.media3.common.audio.SonicAudioProcessor;
 import androidx.media3.common.util.Util;
+import androidx.media3.effect.Presentation;
+import androidx.media3.effect.ScaleToFitTransformation;
 import androidx.media3.exoplayer.source.DefaultMediaSourceFactory;
 import androidx.media3.exoplayer.source.MediaSource;
 import androidx.media3.extractor.DefaultExtractorsFactory;
@@ -728,6 +731,23 @@ public final class TransformerEndToEndTest {
     assertThat(transformationException).hasCauseThat().isInstanceOf(IllegalStateException.class);
   }
 
+  @Test
+  public void startTransformation_withNoOpEffects_transmuxes() throws Exception {
+    MediaItem mediaItem = MediaItem.fromUri(ASSET_URI_PREFIX + FILE_VIDEO_ONLY);
+    int mediaItemHeightPixels = 720;
+    List<Effect> videoEffects = new ArrayList<>();
+    videoEffects.add(Presentation.createForHeight(mediaItemHeightPixels));
+    videoEffects.add(new ScaleToFitTransformation.Builder().build());
+    Transformer transformer =
+        createTransformerBuilder(/* enableFallback= */ false).setVideoEffects(videoEffects).build();
+
+    transformer.startTransformation(mediaItem, outputPath);
+    TransformerTestRunner.runLooper(transformer);
+
+    // Video transcoding in unit tests is not supported.
+    DumpFileAsserts.assertOutput(context, testMuxer, getDumpFileName(FILE_VIDEO_ONLY));
+  }
+
   @Test
   public void getProgress_knownDuration_returnsConsistentStates() throws Exception {
     Transformer transformer = createTransformerBuilder(/* enableFallback= */ false).build();