Transformer: Skip SSIM in tests when fallback is applied.

SSIM calculation requires the input and output dimensions to be identical.

For devices that can't encode the input dimensions, skip SSIM calculations and
log the cause. Only apply this on tests where the encoder may not support the
input file dimensions.

PiperOrigin-RevId: 451364904

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/AndroidTestUtil.java

@@ -229,7 +229,9 @@ public final class AndroidTestUtil {
 
 
   /**
   /**
    * Checks whether the test should be skipped because the device is incapable of decoding and
    * Checks whether the test should be skipped because the device is incapable of decoding and
-   * encoding the given formats. If the test should be skipped, logs the reason for skipping.
+   * encoding the given formats.
+   *
+   * <p>If the test should be skipped, logs the reason for skipping.
    *
    *
    * @param context The {@link Context context}.
    * @param context The {@link Context context}.
    * @param testId The test ID.
    * @param testId The test ID.

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/SsimHelper.java

@@ -68,7 +68,7 @@ public final class SsimHelper {
    * <p>The method compares every {@link #DEFAULT_COMPARISON_INTERVAL n-th} frame from both videos.
    * <p>The method compares every {@link #DEFAULT_COMPARISON_INTERVAL n-th} frame from both videos.
    *
    *
    * @param context The {@link Context}.
    * @param context The {@link Context}.
-   * @param referenceVideoPath The path to the reference video file, must be in {@link
+   * @param referenceVideoPath The path to the reference video file, which must be in {@linkplain
    *     Context#getAssets() Assets}.
    *     Context#getAssets() Assets}.
    * @param actualVideoPath The path to the actual video file.
    * @param actualVideoPath The path to the actual video file.
    * @throws IOException When unable to open the provided video paths.
    * @throws IOException When unable to open the provided video paths.

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/TransformerAndroidTestRunner.java

@@ -33,6 +33,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.concurrent.atomic.AtomicReference;
 import org.checkerframework.checker.nullness.compatqual.NullableType;
 import org.checkerframework.checker.nullness.compatqual.NullableType;
 import org.json.JSONException;
 import org.json.JSONException;
@@ -49,7 +50,7 @@ public class TransformerAndroidTestRunner {
   public static class Builder {
   public static class Builder {
     private final Context context;
     private final Context context;
     private final Transformer transformer;
     private final Transformer transformer;
-    private boolean calculateSsim;
+    private boolean maybeCalculateSsim;
     private int timeoutSeconds;
     private int timeoutSeconds;
     private boolean suppressAnalysisExceptions;
     private boolean suppressAnalysisExceptions;
     @Nullable private Map<String, Object> inputValues;
     @Nullable private Map<String, Object> inputValues;
@@ -81,19 +82,21 @@ public class TransformerAndroidTestRunner {
     }
     }
 
 
     /**
     /**
-     * Sets whether to calculate the SSIM of the transformation output.
+     * Sets whether to try to calculate the SSIM of the transformation output.
+     *
+     * <p>SSIM requires the input and output video dimensions to match. Therefore, if encoder
+     * resolution fallback occurs, this calculation is skipped.
      *
      *
      * <p>The calculation involves decoding and comparing both the input and the output video.
      * <p>The calculation involves decoding and comparing both the input and the output video.
-     * Consequently this calculation is not cost-free. Requires the input and output video to be the
-     * same size.
+     * Consequently this calculation is not cost-free.
      *
      *
      * <p>The default value is {@code false}.
      * <p>The default value is {@code false}.
      *
      *
-     * @param calculateSsim Whether to calculate SSIM.
+     * @param maybeCalculateSsim Whether to try to calculate SSIM.
      * @return This {@link Builder}.
      * @return This {@link Builder}.
      */
      */
-    public Builder setCalculateSsim(boolean calculateSsim) {
-      this.calculateSsim = calculateSsim;
+    public Builder setMaybeCalculateSsim(boolean maybeCalculateSsim) {
+      this.maybeCalculateSsim = maybeCalculateSsim;
       return this;
       return this;
     }
     }
 
 
@@ -137,7 +140,7 @@ public class TransformerAndroidTestRunner {
           context,
           context,
           transformer,
           transformer,
           timeoutSeconds,
           timeoutSeconds,
-          calculateSsim,
+          maybeCalculateSsim,
           suppressAnalysisExceptions,
           suppressAnalysisExceptions,
           inputValues);
           inputValues);
     }
     }
@@ -147,7 +150,7 @@ public class TransformerAndroidTestRunner {
   private final CodecNameForwardingCodecFactory transformerCodecFactory;
   private final CodecNameForwardingCodecFactory transformerCodecFactory;
   private final Transformer transformer;
   private final Transformer transformer;
   private final int timeoutSeconds;
   private final int timeoutSeconds;
-  private final boolean calculateSsim;
+  private final boolean maybeCalculateSsim;
   private final boolean suppressAnalysisExceptions;
   private final boolean suppressAnalysisExceptions;
   @Nullable private final Map<String, Object> inputValues;
   @Nullable private final Map<String, Object> inputValues;
 
 
@@ -155,7 +158,7 @@ public class TransformerAndroidTestRunner {
       Context context,
       Context context,
       Transformer transformer,
       Transformer transformer,
       int timeoutSeconds,
       int timeoutSeconds,
-      boolean calculateSsim,
+      boolean maybeCalculateSsim,
       boolean suppressAnalysisExceptions,
       boolean suppressAnalysisExceptions,
       @Nullable Map<String, Object> inputValues) {
       @Nullable Map<String, Object> inputValues) {
     this.context = context;
     this.context = context;
@@ -168,7 +171,7 @@ public class TransformerAndroidTestRunner {
             .setEncoderFactory(transformerCodecFactory)
             .setEncoderFactory(transformerCodecFactory)
             .build();
             .build();
     this.timeoutSeconds = timeoutSeconds;
     this.timeoutSeconds = timeoutSeconds;
-    this.calculateSsim = calculateSsim;
+    this.maybeCalculateSsim = maybeCalculateSsim;
     this.suppressAnalysisExceptions = suppressAnalysisExceptions;
     this.suppressAnalysisExceptions = suppressAnalysisExceptions;
     this.inputValues = inputValues;
     this.inputValues = inputValues;
   }
   }
@@ -220,7 +223,7 @@ public class TransformerAndroidTestRunner {
   private TransformationTestResult runInternal(String testId, MediaItem mediaItem)
   private TransformationTestResult runInternal(String testId, MediaItem mediaItem)
       throws InterruptedException, IOException, TimeoutException, TransformationException {
       throws InterruptedException, IOException, TimeoutException, TransformationException {
     if (!mediaItem.clippingConfiguration.equals(MediaItem.ClippingConfiguration.UNSET)
     if (!mediaItem.clippingConfiguration.equals(MediaItem.ClippingConfiguration.UNSET)
-        && calculateSsim) {
+        && maybeCalculateSsim) {
       throw new UnsupportedOperationException(
       throw new UnsupportedOperationException(
           "SSIM calculation is not supported for clipped inputs.");
           "SSIM calculation is not supported for clipped inputs.");
     }
     }
@@ -231,6 +234,7 @@ public class TransformerAndroidTestRunner {
     AtomicReference<@NullableType TransformationResult> transformationResultReference =
     AtomicReference<@NullableType TransformationResult> transformationResultReference =
         new AtomicReference<>();
         new AtomicReference<>();
     CountDownLatch countDownLatch = new CountDownLatch(1);
     CountDownLatch countDownLatch = new CountDownLatch(1);
+    AtomicBoolean fallbackResolutionApplied = new AtomicBoolean(false);
     long startTimeMs = SystemClock.DEFAULT.elapsedRealtime();
     long startTimeMs = SystemClock.DEFAULT.elapsedRealtime();
 
 
     Transformer testTransformer =
     Transformer testTransformer =
@@ -251,6 +255,20 @@ public class TransformerAndroidTestRunner {
                     transformationExceptionReference.set(exception);
                     transformationExceptionReference.set(exception);
                     countDownLatch.countDown();
                     countDownLatch.countDown();
                   }
                   }
+
+                  @Override
+                  public void onFallbackApplied(
+                      MediaItem inputMediaItem,
+                      TransformationRequest originalTransformationRequest,
+                      TransformationRequest fallbackTransformationRequest) {
+                    // Note: As TransformationRequest only reports the output height but not the
+                    // output width, it's not possible to check whether the encoder has changed
+                    // the output aspect ratio.
+                    if (originalTransformationRequest.outputHeight
+                        != fallbackTransformationRequest.outputHeight) {
+                      fallbackResolutionApplied.set(true);
+                    }
+                  }
                 })
                 })
             .build();
             .build();
 
 
@@ -299,15 +317,23 @@ public class TransformerAndroidTestRunner {
             .setFilePath(outputVideoFile.getPath())
             .setFilePath(outputVideoFile.getPath())
             .setElapsedTimeMs(elapsedTimeMs);
             .setElapsedTimeMs(elapsedTimeMs);
 
 
+    if (!maybeCalculateSsim) {
+      return resultBuilder.build();
+    }
+    if (fallbackResolutionApplied.get()) {
+      Log.i(
+          TAG,
+          testId
+              + ": Skipping SSIM calculation because an encoder resolution fallback was applied.");
+      return resultBuilder.build();
+    }
     try {
     try {
-      if (calculateSsim) {
-        double ssim =
-            SsimHelper.calculate(
-                context,
-                /* referenceVideoPath= */ checkNotNull(mediaItem.localConfiguration).uri.toString(),
-                outputVideoFile.getPath());
-        resultBuilder.setSsim(ssim);
-      }
+      double ssim =
+          SsimHelper.calculate(
+              context,
+              /* referenceVideoPath= */ checkNotNull(mediaItem.localConfiguration).uri.toString(),
+              outputVideoFile.getPath());
+      resultBuilder.setSsim(ssim);
     } catch (InterruptedException interruptedException) {
     } catch (InterruptedException interruptedException) {
       // InterruptedException is a special unexpected case because it is not related to Ssim
       // InterruptedException is a special unexpected case because it is not related to Ssim
       // calculation, so it should be thrown, rather than processed as part of the
       // calculation, so it should be thrown, rather than processed as part of the
@@ -317,7 +343,7 @@ public class TransformerAndroidTestRunner {
       if (Util.SDK_INT == 21 && "Nexus 5".equals(Util.MODEL)) { // b/233584640
       if (Util.SDK_INT == 21 && "Nexus 5".equals(Util.MODEL)) { // b/233584640
         Log.i(TAG, testId + ": Skipping SSIM calculation due to known device-specific issue");
         Log.i(TAG, testId + ": Skipping SSIM calculation due to known device-specific issue");
       } else {
       } else {
-        // Catch all (checked and unchecked) failures throw by the SsimHelper and process them as
+        // Catch all (checked and unchecked) failures thrown by the SsimHelper and process them as
         // part of the TransformationTestResult.
         // part of the TransformationTestResult.
         Exception analysisException =
         Exception analysisException =
             analysisFailure instanceof Exception
             analysisFailure instanceof Exception

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/mh/TranscodeQualityTest.java

@@ -58,7 +58,7 @@ public final class TranscodeQualityTest {
 
 
     TransformationTestResult result =
     TransformationTestResult result =
         new TransformerAndroidTestRunner.Builder(context, transformer)
         new TransformerAndroidTestRunner.Builder(context, transformer)
-            .setCalculateSsim(true)
+            .setMaybeCalculateSsim(true)
             .build()
             .build()
             .run(
             .run(
                 testId,
                 testId,
@@ -95,7 +95,7 @@ public final class TranscodeQualityTest {
 
 
     TransformationTestResult result =
     TransformationTestResult result =
         new TransformerAndroidTestRunner.Builder(context, transformer)
         new TransformerAndroidTestRunner.Builder(context, transformer)
-            .setCalculateSsim(true)
+            .setMaybeCalculateSsim(true)
             .build()
             .build()
             .run(
             .run(
                 testId,
                 testId,
@@ -125,7 +125,7 @@ public final class TranscodeQualityTest {
 
 
     TransformationTestResult result =
     TransformationTestResult result =
         new TransformerAndroidTestRunner.Builder(context, transformer)
         new TransformerAndroidTestRunner.Builder(context, transformer)
-            .setCalculateSsim(true)
+            .setMaybeCalculateSsim(true)
             .build()
             .build()
             .run(
             .run(
                 testId,
                 testId,

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/mh/TransformationTest.java

@@ -54,7 +54,7 @@ public class TransformationTest {
             .setEncoderFactory(AndroidTestUtil.FORCE_ENCODE_ENCODER_FACTORY)
             .setEncoderFactory(AndroidTestUtil.FORCE_ENCODE_ENCODER_FACTORY)
             .build();
             .build();
     new TransformerAndroidTestRunner.Builder(context, transformer)
     new TransformerAndroidTestRunner.Builder(context, transformer)
-        .setCalculateSsim(true)
+        .setMaybeCalculateSsim(true)
         .build()
         .build()
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
   }
   }
@@ -84,7 +84,7 @@ public class TransformationTest {
                     /* enableFallback= */ true))
                     /* enableFallback= */ true))
             .build();
             .build();
     new TransformerAndroidTestRunner.Builder(context, transformer)
     new TransformerAndroidTestRunner.Builder(context, transformer)
-        .setCalculateSsim(true)
+        .setMaybeCalculateSsim(true)
         .build()
         .build()
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
   }
   }
@@ -105,7 +105,7 @@ public class TransformationTest {
     Transformer transformer =
     Transformer transformer =
         new Transformer.Builder(context).setEncoderFactory(FORCE_ENCODE_ENCODER_FACTORY).build();
         new Transformer.Builder(context).setEncoderFactory(FORCE_ENCODE_ENCODER_FACTORY).build();
     new TransformerAndroidTestRunner.Builder(context, transformer)
     new TransformerAndroidTestRunner.Builder(context, transformer)
-        .setCalculateSsim(true)
+        .setMaybeCalculateSsim(true)
         .setTimeoutSeconds(180)
         .setTimeoutSeconds(180)
         .build()
         .build()
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_REMOTE_4K60_PORTRAIT_URI_STRING)));
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_REMOTE_4K60_PORTRAIT_URI_STRING)));
@@ -121,7 +121,7 @@ public class TransformationTest {
             .setRemoveAudio(true)
             .setRemoveAudio(true)
             .build();
             .build();
     new TransformerAndroidTestRunner.Builder(context, transformer)
     new TransformerAndroidTestRunner.Builder(context, transformer)
-        .setCalculateSsim(true)
+        .setMaybeCalculateSsim(true)
         .build()
         .build()
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
         .run(testId, MediaItem.fromUri(Uri.parse(MP4_ASSET_WITH_INCREASING_TIMESTAMPS_URI_STRING)));
   }
   }

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/mh/analysis/BitrateAnalysisTest.java

@@ -116,7 +116,7 @@ public class BitrateAnalysisTest {
 
 
     new TransformerAndroidTestRunner.Builder(context, transformer)
     new TransformerAndroidTestRunner.Builder(context, transformer)
         .setInputValues(inputValues)
         .setInputValues(inputValues)
-        .setCalculateSsim(true)
+        .setMaybeCalculateSsim(true)
         .build()
         .build()
         .run(testId, MediaItem.fromUri(Uri.parse(fileUri)));
         .run(testId, MediaItem.fromUri(Uri.parse(fileUri)));
   }
   }

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/Transformer.java

@@ -511,7 +511,9 @@ public final class Transformer {
      * @param inputMediaItem The {@link MediaItem} for which the transformation is requested.
      * @param inputMediaItem The {@link MediaItem} for which the transformation is requested.
      * @param originalTransformationRequest The unsupported {@link TransformationRequest} used when
      * @param originalTransformationRequest The unsupported {@link TransformationRequest} used when
      *     building {@link Transformer}.
      *     building {@link Transformer}.
-     * @param fallbackTransformationRequest The alternative {@link TransformationRequest}.
+     * @param fallbackTransformationRequest The alternative {@link TransformationRequest}, with
+     *     supported {@link TransformationRequest#outputHeight} and {@link
+     *     TransformationRequest#videoMimeType} values set.
      */
      */
     default void onFallbackApplied(
     default void onFallbackApplied(
         MediaItem inputMediaItem,
         MediaItem inputMediaItem,