Use ceiling divide logic in AudioTrackPositionTracker.hasPendingData

This fixes a bug with playing very short audio files, introduced by
fe710871aa

The existing code using floor integer division results in playback never
transitioning to `STATE_ENDED` because at the end of playback for the
short sample clip provided `currentPositionUs=189937`,
`outputSampleRate=16000` and `(189937 * 16000) / 1000000 = 3038.992`,
while `writtenFrames=3039`. This is fixed by using `Util.ceilDivide`
so we return `3039`, which means
`AudioTrackPositionTracker.hasPendingData()` returns `false` (since
`writtenFrames ==
durationUsToFrames(getCurrentPositionUs(/* sourceEnded= */ false))`).

Issue: androidx/media#538
PiperOrigin-RevId: 554481782
(cherry picked from commit 6e91f0d4c5)

RELEASENOTES.md

@@ -15,6 +15,10 @@
     *   Add additional fields to Common Media Client Data (CMCD) logging:
         streaming format (sf), stream type (st), version (v), top birate (tb),
         object duration (d) and measured throughput (mtp).
+*   Audio:
+    *   Fix a bug where `Player.getState()` never transitioned to `STATE_ENDED`
+        when playing very short files
+        ([#538](https://github.com/androidx/media/issues/538)).
 *   Audio Offload:
     *   Prepend Ogg ID Header and Comment Header Pages to bitstream for
         offloaded Opus playback in accordance with RFC 7845.

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

@@ -1430,6 +1430,40 @@ public final class Util {
     return (timeMs == C.TIME_UNSET || timeMs == C.TIME_END_OF_SOURCE) ? timeMs : (timeMs * 1000);
   }
 
+  /**
+   * Returns the total duration (in microseconds) of {@code sampleCount} samples of equal duration
+   * at {@code sampleRate}.
+   *
+   * <p>If {@code sampleRate} is less than {@link C#MICROS_PER_SECOND}, the duration produced by
+   * this method can be reversed to the original sample count using {@link
+   * #durationUsToSampleCount(long, int)}.
+   *
+   * @param sampleCount The number of samples.
+   * @param sampleRate The sample rate, in samples per second.
+   * @return The total duration, in microseconds, of {@code sampleCount} samples.
+   */
+  @UnstableApi
+  public static long sampleCountToDurationUs(long sampleCount, int sampleRate) {
+    return (sampleCount * C.MICROS_PER_SECOND) / sampleRate;
+  }
+
+  /**
+   * Returns the number of samples required to represent {@code durationUs} of media at {@code
+   * sampleRate}, assuming all samples are equal duration except the last one which may be shorter.
+   *
+   * <p>The result of this method <b>cannot</b> be generally reversed to the original duration with
+   * {@link #sampleCountToDurationUs(long, int)}, due to information lost when rounding to a whole
+   * number of samples.
+   *
+   * @param durationUs The duration in microseconds.
+   * @param sampleRate The sample rate in samples per second.
+   * @return The number of samples required to represent {@code durationUs}.
+   */
+  @UnstableApi
+  public static long durationUsToSampleCount(long durationUs, int sampleRate) {
+    return Util.ceilDivide(durationUs * sampleRate, C.MICROS_PER_SECOND);
+  }
+
   /**
    * Parses an xs:duration attribute value, returning the parsed duration in milliseconds.
    *

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

@@ -27,6 +27,7 @@ import static androidx.media3.common.util.Util.parseXsDateTime;
 import static androidx.media3.common.util.Util.parseXsDuration;
 import static androidx.media3.common.util.Util.unescapeFileName;
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth.assertWithMessage;
 import static org.junit.Assert.assertThrows;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -832,6 +833,21 @@ public class UtilTest {
     assertThrows(NoSuchElementException.class, () -> maxValue(new SparseLongArray()));
   }
 
+  @Test
+  public void sampleCountToDuration_thenDurationToSampleCount_returnsOriginalValue() {
+    // Use co-prime increments, to maximise 'discord' between sampleCount and sampleRate.
+    for (long originalSampleCount = 0; originalSampleCount < 100_000; originalSampleCount += 97) {
+      for (int sampleRate = 89; sampleRate < 1_000_000; sampleRate += 89) {
+        long calculatedSampleCount =
+            Util.durationUsToSampleCount(
+                Util.sampleCountToDurationUs(originalSampleCount, sampleRate), sampleRate);
+        assertWithMessage("sampleCount=%s, sampleRate=%s", originalSampleCount, sampleRate)
+            .that(calculatedSampleCount)
+            .isEqualTo(originalSampleCount);
+      }
+    }
+  }
+
   @Test
   public void parseXsDuration_returnsParsedDurationInMillis() {
     assertThat(parseXsDuration("PT150.279S")).isEqualTo(150279L);

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/AudioTrackPositionTracker.java

@@ -17,6 +17,8 @@ package androidx.media3.exoplayer.audio;
 
 import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Util.castNonNull;
+import static androidx.media3.common.util.Util.durationUsToSampleCount;
+import static androidx.media3.common.util.Util.sampleCountToDurationUs;
 import static java.lang.Math.max;
 import static java.lang.Math.min;
 import static java.lang.annotation.ElementType.TYPE_USE;
@@ -238,7 +240,10 @@ import java.lang.reflect.Method;
     outputSampleRate = audioTrack.getSampleRate();
     needsPassthroughWorkarounds = isPassthrough && needsPassthroughWorkarounds(outputEncoding);
     isOutputPcm = Util.isEncodingLinearPcm(outputEncoding);
-    bufferSizeUs = isOutputPcm ? framesToDurationUs(bufferSize / outputPcmFrameSize) : C.TIME_UNSET;
+    bufferSizeUs =
+        isOutputPcm
+            ? sampleCountToDurationUs(bufferSize / outputPcmFrameSize, outputSampleRate)
+            : C.TIME_UNSET;
     rawPlaybackHeadPosition = 0;
     rawPlaybackHeadWrapCount = 0;
     passthroughWorkaroundPauseOffset = 0;
@@ -274,7 +279,7 @@ import java.lang.reflect.Method;
     if (useGetTimestampMode) {
       // Calculate the speed-adjusted position using the timestamp (which may be in the future).
       long timestampPositionFrames = audioTimestampPoller.getTimestampPositionFrames();
-      long timestampPositionUs = framesToDurationUs(timestampPositionFrames);
+      long timestampPositionUs = sampleCountToDurationUs(timestampPositionFrames, outputSampleRate);
       long elapsedSinceTimestampUs = systemTimeUs - audioTimestampPoller.getTimestampSystemTimeUs();
       elapsedSinceTimestampUs =
           Util.getMediaDurationForPlayoutDuration(elapsedSinceTimestampUs, audioTrackPlaybackSpeed);
@@ -420,7 +425,8 @@ import java.lang.reflect.Method;
    * @return Whether the audio track has any pending data to play out.
    */
   public boolean hasPendingData(long writtenFrames) {
-    return writtenFrames > durationUsToFrames(getCurrentPositionUs(/* sourceEnded= */ false))
+    long currentPositionUs = getCurrentPositionUs(/* sourceEnded= */ false);
+    return writtenFrames > durationUsToSampleCount(currentPositionUs, outputSampleRate)
         || forceHasPendingData();
   }
 
@@ -491,23 +497,18 @@ import java.lang.reflect.Method;
     }
 
     // Check the timestamp and accept/reject it.
-    long audioTimestampSystemTimeUs = audioTimestampPoller.getTimestampSystemTimeUs();
+    long timestampSystemTimeUs = audioTimestampPoller.getTimestampSystemTimeUs();
-    long audioTimestampPositionFrames = audioTimestampPoller.getTimestampPositionFrames();
+    long timestampPositionFrames = audioTimestampPoller.getTimestampPositionFrames();
     long playbackPositionUs = getPlaybackHeadPositionUs();
-    if (Math.abs(audioTimestampSystemTimeUs - systemTimeUs) > MAX_AUDIO_TIMESTAMP_OFFSET_US) {
+    if (Math.abs(timestampSystemTimeUs - systemTimeUs) > MAX_AUDIO_TIMESTAMP_OFFSET_US) {
       listener.onSystemTimeUsMismatch(
-          audioTimestampPositionFrames,
+          timestampPositionFrames, timestampSystemTimeUs, systemTimeUs, playbackPositionUs);
-          audioTimestampSystemTimeUs,
-          systemTimeUs,
-          playbackPositionUs);
       audioTimestampPoller.rejectTimestamp();
-    } else if (Math.abs(framesToDurationUs(audioTimestampPositionFrames) - playbackPositionUs)
+    } else if (Math.abs(
+            sampleCountToDurationUs(timestampPositionFrames, outputSampleRate) - playbackPositionUs)
         > MAX_AUDIO_TIMESTAMP_OFFSET_US) {
       listener.onPositionFramesMismatch(
-          audioTimestampPositionFrames,
+          timestampPositionFrames, timestampSystemTimeUs, systemTimeUs, playbackPositionUs);
-          audioTimestampSystemTimeUs,
-          systemTimeUs,
-          playbackPositionUs);
       audioTimestampPoller.rejectTimestamp();
     } else {
       audioTimestampPoller.acceptTimestamp();
@@ -539,14 +540,6 @@ import java.lang.reflect.Method;
     }
   }
 
-  private long framesToDurationUs(long frameCount) {
-    return (frameCount * C.MICROS_PER_SECOND) / outputSampleRate;
-  }
-
-  private long durationUsToFrames(long durationUs) {
-    return (durationUs * outputSampleRate) / C.MICROS_PER_SECOND;
-  }
-
   private void resetSyncParams() {
     smoothedPlayheadOffsetUs = 0;
     playheadOffsetCount = 0;
@@ -578,7 +571,7 @@ import java.lang.reflect.Method;
   }
 
   private long getPlaybackHeadPositionUs() {
-    return framesToDurationUs(getPlaybackHeadPosition());
+    return sampleCountToDurationUs(getPlaybackHeadPosition(), outputSampleRate);
   }
 
   /**
@@ -596,7 +589,7 @@ import java.lang.reflect.Method;
       long elapsedTimeSinceStopUs = (currentTimeMs * 1000) - stopTimestampUs;
       long mediaTimeSinceStopUs =
           Util.getMediaDurationForPlayoutDuration(elapsedTimeSinceStopUs, audioTrackPlaybackSpeed);
-      long framesSinceStop = durationUsToFrames(mediaTimeSinceStopUs);
+      long framesSinceStop = durationUsToSampleCount(mediaTimeSinceStopUs, outputSampleRate);
       return min(endPlaybackHeadPosition, stopPlaybackHeadPosition + framesSinceStop);
     }
     if (currentTimeMs - lastRawPlaybackHeadPositionSampleTimeMs

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/DefaultAudioSink.java

@@ -2086,11 +2086,11 @@ public final class DefaultAudioSink implements AudioSink {
     }
 
     public long inputFramesToDurationUs(long frameCount) {
-      return (frameCount * C.MICROS_PER_SECOND) / inputFormat.sampleRate;
+      return Util.sampleCountToDurationUs(frameCount, inputFormat.sampleRate);
     }
 
     public long framesToDurationUs(long frameCount) {
-      return (frameCount * C.MICROS_PER_SECOND) / outputSampleRate;
+      return Util.sampleCountToDurationUs(frameCount, outputSampleRate);
     }
 
     public AudioTrack buildAudioTrack(