Add TransformerTestBuilderFactory to make transformer testable by apps

PiperOrigin-RevId: 495821660

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

@@ -428,7 +428,7 @@ public final class Transformer {
      */
     @CanIgnoreReturnValue
     @VisibleForTesting
-    /* package */ Builder setClock(Clock clock) {
+    public Builder setClock(Clock clock) {
       this.clock = clock;
       this.listeners = listeners.copy(looper, clock, (listener, flags) -> {});
       return this;

robolectricutils/build.gradle

@@ -20,6 +20,7 @@ dependencies {
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     implementation 'org.robolectric:robolectric:' + robolectricVersion
     implementation project(modulePrefix + 'library-core')
+    implementation project(modulePrefix + ':lib-transformer')
     implementation project(modulePrefix + 'testutils')
 }
 

testutils/build.gradle

@@ -26,6 +26,7 @@ dependencies {
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
     implementation 'com.squareup.okhttp3:mockwebserver:' + okhttpVersion
     implementation project(modulePrefix + 'library-core')
+    implementation project(modulePrefix + ':lib-transformer')
     testImplementation 'org.robolectric:robolectric:' + robolectricVersion
 }
 

library/transformer/src/test/java/com/google/android/exoplayer2/transformer/TestMuxer.java → testutils/src/main/java/com/google/android/exoplayer2/testutil/TestMuxer.java

@@ -13,11 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.google.android.exoplayer2.transformer;
+package com.google.android.exoplayer2.testutil;
 
 import com.google.android.exoplayer2.Format;
-import com.google.android.exoplayer2.testutil.DumpableFormat;
-import com.google.android.exoplayer2.testutil.Dumper;
+import com.google.android.exoplayer2.transformer.Muxer;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Arrays;

testutils/src/main/java/com/google/android/exoplayer2/testutil/TestTransformerBuilderFactory.java

+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.testutil;
+
+import static com.google.android.exoplayer2.util.Assertions.checkStateNotNull;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.os.ParcelFileDescriptor;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.transformer.DefaultEncoderFactory;
+import com.google.android.exoplayer2.transformer.DefaultMuxer;
+import com.google.android.exoplayer2.transformer.Muxer;
+import com.google.android.exoplayer2.transformer.Transformer;
+import com.google.android.exoplayer2.util.Clock;
+import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
+
+/**
+ * Creates a {@link Transformer.Builder} setting up some of the common resources needed for testing
+ * {@link Transformer}.
+ */
+public final class TestTransformerBuilderFactory {
+
+  private final Context context;
+
+  private static @MonotonicNonNull TestMuxer testMuxer;
+  private long maxDelayBetweenSamplesMs;
+
+  /** Creates a new instance */
+  public TestTransformerBuilderFactory(Context context) {
+    this.context = context;
+    maxDelayBetweenSamplesMs = DefaultMuxer.Factory.DEFAULT_MAX_DELAY_BETWEEN_SAMPLES_MS;
+  }
+
+  /**
+   * Sets the muxer's {@linkplain Muxer#getMaxDelayBetweenSamplesMs() max delay} between samples.
+   */
+  @CanIgnoreReturnValue
+  public TestTransformerBuilderFactory setMaxDelayBetweenSamplesMs(long maxDelayBetweenSamplesMs) {
+    this.maxDelayBetweenSamplesMs = maxDelayBetweenSamplesMs;
+    return this;
+  }
+
+  /** Returns a {@link Transformer.Builder} using the provided values or their defaults. */
+  @SuppressLint("VisibleForTests") // Suppresses warning on setting the clock outside of a test file
+  public Transformer.Builder create(boolean enableFallback) {
+    Clock clock = new FakeClock(/* isAutoAdvancing= */ true);
+    Muxer.Factory defaultMuxerFactory = new DefaultMuxer.Factory(maxDelayBetweenSamplesMs);
+    return new Transformer.Builder(context)
+        .setClock(clock)
+        .setMuxerFactory(new TestMuxerFactory(defaultMuxerFactory))
+        .setEncoderFactory(
+            new DefaultEncoderFactory.Builder(context).setEnableFallback(enableFallback).build());
+  }
+
+  /**
+   * Returns the test muxer used in the {@link Transformer.Builder}.
+   *
+   * <p>This method should only be called after the transformation is completed.
+   */
+  public TestMuxer getTestMuxer() {
+    return checkStateNotNull(testMuxer);
+  }
+
+  private static final class TestMuxerFactory implements Muxer.Factory {
+
+    private final Muxer.Factory defaultMuxerFactory;
+
+    public TestMuxerFactory(Muxer.Factory defaultMuxerFactory) {
+      this.defaultMuxerFactory = defaultMuxerFactory;
+    }
+
+    @Override
+    public Muxer create(String path) throws Muxer.MuxerException {
+      testMuxer = new TestMuxer(path, defaultMuxerFactory);
+      return testMuxer;
+    }
+
+    @Override
+    public Muxer create(ParcelFileDescriptor parcelFileDescriptor) throws Muxer.MuxerException {
+      testMuxer = new TestMuxer("FD:" + parcelFileDescriptor.getFd(), defaultMuxerFactory);
+      return testMuxer;
+    }
+
+    @Override
+    public ImmutableList<String> getSupportedSampleMimeTypes(@C.TrackType int trackType) {
+      return defaultMuxerFactory.getSupportedSampleMimeTypes(trackType);
+    }
+  }
+}