Match with ExoPlayer seeking when using CompositionPlayer

In a image sequence, seek to after the image duration should render the final
image frame. But currently it hangs as ConstantRateTimestampIterator doesn't
output any timestamp in this case

PiperOrigin-RevId: 724295475

libraries/common/src/main/java/androidx/media3/common/util/ConstantRateTimestampIterator.java

@@ -17,6 +17,7 @@ package androidx.media3.common.util;
 
 import static androidx.media3.common.util.Assertions.checkArgument;
 import static androidx.media3.common.util.Assertions.checkState;
+import static java.lang.Math.max;
 import static java.lang.Math.round;
 
 import androidx.annotation.FloatRange;
@@ -70,7 +71,8 @@ public final class ConstantRateTimestampIterator implements TimestampIterator {
     this.endPositionUs = endPositionUs;
     this.frameRate = frameRate;
     float durationSecs = (endPositionUs - startPositionUs) / (float) C.MICROS_PER_SECOND;
-    this.totalNumberOfFramesToAdd = round(frameRate * durationSecs);
+    // Generate at least one timestamp so that at least one frame is produced when seeking.
+    this.totalNumberOfFramesToAdd = max(round(frameRate * durationSecs), 1);
     framesDurationUs = C.MICROS_PER_SECOND / frameRate;
   }
 

libraries/common/src/test/java/androidx/media3/common/util/ConstantRateTimestampIteratorTest.java

@@ -67,12 +67,12 @@ public class ConstantRateTimestampIteratorTest {
   }
 
   @Test
-  public void timestampIterator_smallDuration_generatesEmptyIterator() {
+  public void timestampIterator_smallDuration_generatesOneTimestamp() {
     ConstantRateTimestampIterator constantRateTimestampIterator =
         new ConstantRateTimestampIterator(/* durationUs= */ 1, /* frameRate= */ 2);
 
-    assertThat(generateList(constantRateTimestampIterator)).isEmpty();
+    assertThat(generateList(constantRateTimestampIterator)).containsExactly(0L);
-    assertThat(constantRateTimestampIterator.getLastTimestampUs()).isEqualTo(C.TIME_UNSET);
+    assertThat(constantRateTimestampIterator.getLastTimestampUs()).isEqualTo(0L);
   }
 
   @Test
@@ -110,15 +110,15 @@ public class ConstantRateTimestampIteratorTest {
   }
 
   @Test
-  public void timestampIterator_withNoTimestampsWithinParameters_generatesNoTimestamp() {
+  public void timestampIterator_withNoTimestampsWithinParameters_generatesOneTimestamp() {
     ConstantRateTimestampIterator constantRateTimestampIterator =
         new ConstantRateTimestampIterator(
             /* startPositionUs= */ 900_000L,
             /* endPositionUs= */ C.MICROS_PER_SECOND,
             /* frameRate= */ 3);
 
-    assertThat(generateList(constantRateTimestampIterator)).isEmpty();
+    assertThat(generateList(constantRateTimestampIterator)).containsExactly(900_000L);
-    assertThat(constantRateTimestampIterator.getLastTimestampUs()).isEqualTo(C.TIME_UNSET);
+    assertThat(constantRateTimestampIterator.getLastTimestampUs()).isEqualTo(900_000L);
   }
 
   private static List<Long> generateList(TimestampIterator iterator) {

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

@@ -355,6 +355,47 @@ public class CompositionPlayerSeekTest {
         .isEqualTo(sequenceTimestampsUs);
   }
 
+  @Test
+  public void seekToEndOfSecondImage_afterPlayingSingleSequenceOfTwoImages() throws Exception {
+    // Seeks to the end of the second image
+    long seekTimeMs = usToMs(2 * IMAGE_DURATION_US);
+    ImmutableList<Long> sequenceTimestampsUs =
+        new ImmutableList.Builder<Long>()
+            // Plays the first image
+            .addAll(IMAGE_TIMESTAMPS_US)
+            // Plays the second image
+            .addAll(
+                transform(IMAGE_TIMESTAMPS_US, timestampUs -> (IMAGE_DURATION_US + timestampUs)))
+            // Plays the last image frame, which is one microsecond smaller than the total duration.
+            .add(399_999L)
+            .build();
+
+    assertThat(
+            playSequenceUntilEndedAndSeekAndGetTimestampsUs(
+                ImmutableList.of(IMAGE_MEDIA_ITEM, IMAGE_MEDIA_ITEM), seekTimeMs))
+        .isEqualTo(sequenceTimestampsUs);
+  }
+
+  @Test
+  public void seekToAfterEndOfSecondImage_afterPlayingSingleSequenceOfTwoImages() throws Exception {
+    long seekTimeMs = usToMs(3 * IMAGE_DURATION_US);
+    ImmutableList<Long> sequenceTimestampsUs =
+        new ImmutableList.Builder<Long>()
+            // Plays the first image
+            .addAll(IMAGE_TIMESTAMPS_US)
+            // Plays the second image
+            .addAll(
+                transform(IMAGE_TIMESTAMPS_US, timestampUs -> (IMAGE_DURATION_US + timestampUs)))
+            // Plays the last image frame, which is one microsecond smaller than the total duration.
+            .add(399_999L)
+            .build();
+
+    assertThat(
+            playSequenceUntilEndedAndSeekAndGetTimestampsUs(
+                ImmutableList.of(IMAGE_MEDIA_ITEM, IMAGE_MEDIA_ITEM), seekTimeMs))
+        .isEqualTo(sequenceTimestampsUs);
+  }
+
   @Test
   public void seekToZero_afterPlayingSingleSequenceOfVideoAndImage() throws Exception {
     maybeSkipTest();