Remove initial bitrate estimate from AdaptiveTrackSelection.

This value can now be set in the DefaultBandwidthMeter instead. As a result
NO_VALUE can be removed from BandwidthMeter as we now always provide an
estimate.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=187865341

RELEASENOTES.md

@@ -2,6 +2,8 @@
 
 ### dev-v2 (not yet released) ###
 
+* Moved initial bitrate estimate from `AdaptiveTrackSelection` to
+  `DefaultBandwidthMeter`.
 * UI components:
   * Add support for listening to `AspectRatioFrameLayout`'s aspect ratio update
     ([#3736](https://github.com/google/ExoPlayer/issues/3736)).

library/core/src/main/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelection.java

@@ -36,7 +36,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
   public static final class Factory implements TrackSelection.Factory {
 
     private final BandwidthMeter bandwidthMeter;
-    private final int maxInitialBitrate;
     private final int minDurationForQualityIncreaseMs;
     private final int maxDurationForQualityDecreaseMs;
     private final int minDurationToRetainAfterDiscardMs;
@@ -51,7 +50,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
     public Factory(BandwidthMeter bandwidthMeter) {
       this(
           bandwidthMeter,
-          DEFAULT_MAX_INITIAL_BITRATE,
           DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
           DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
           DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
@@ -63,26 +61,26 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
 
     /**
      * @param bandwidthMeter Provides an estimate of the currently available bandwidth.
-     * @param maxInitialBitrate The maximum bitrate in bits per second that should be assumed
+     * @param minDurationForQualityIncreaseMs The minimum duration of buffered data required for the
-     *     when a bandwidth estimate is unavailable.
+     *     selected track to switch to one of higher quality.
-     * @param minDurationForQualityIncreaseMs The minimum duration of buffered data required for
+     * @param maxDurationForQualityDecreaseMs The maximum duration of buffered data required for the
-     *     the selected track to switch to one of higher quality.
+     *     selected track to switch to one of lower quality.
-     * @param maxDurationForQualityDecreaseMs The maximum duration of buffered data required for
-     *     the selected track to switch to one of lower quality.
      * @param minDurationToRetainAfterDiscardMs When switching to a track of significantly higher
      *     quality, the selection may indicate that media already buffered at the lower quality can
      *     be discarded to speed up the switch. This is the minimum duration of media that must be
      *     retained at the lower quality.
      * @param bandwidthFraction The fraction of the available bandwidth that the selection should
-     *     consider available for use. Setting to a value less than 1 is recommended to account
+     *     consider available for use. Setting to a value less than 1 is recommended to account for
-     *     for inaccuracies in the bandwidth estimator.
+     *     inaccuracies in the bandwidth estimator.
      */
-    public Factory(BandwidthMeter bandwidthMeter, int maxInitialBitrate,
+    public Factory(
-        int minDurationForQualityIncreaseMs, int maxDurationForQualityDecreaseMs,
+        BandwidthMeter bandwidthMeter,
-        int minDurationToRetainAfterDiscardMs, float bandwidthFraction) {
+        int minDurationForQualityIncreaseMs,
+        int maxDurationForQualityDecreaseMs,
+        int minDurationToRetainAfterDiscardMs,
+        float bandwidthFraction) {
       this(
           bandwidthMeter,
-          maxInitialBitrate,
           minDurationForQualityIncreaseMs,
           maxDurationForQualityDecreaseMs,
           minDurationToRetainAfterDiscardMs,
@@ -93,9 +91,7 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
     }
 
     /**
-     * @param bandwidthMeter Provides an estimate of the currently available bandwidth.
+     * @param bandwidthMeter Provides an estimate of the currently available bandwidth..
-     * @param maxInitialBitrate The maximum bitrate in bits per second that should be assumed when a
-     *     bandwidth estimate is unavailable.
      * @param minDurationForQualityIncreaseMs The minimum duration of buffered data required for the
      *     selected track to switch to one of higher quality.
      * @param maxDurationForQualityDecreaseMs The maximum duration of buffered data required for the
@@ -121,7 +117,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
      */
     public Factory(
         BandwidthMeter bandwidthMeter,
-        int maxInitialBitrate,
         int minDurationForQualityIncreaseMs,
         int maxDurationForQualityDecreaseMs,
         int minDurationToRetainAfterDiscardMs,
@@ -130,7 +125,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         long minTimeBetweenBufferReevaluationMs,
         Clock clock) {
       this.bandwidthMeter = bandwidthMeter;
-      this.maxInitialBitrate = maxInitialBitrate;
       this.minDurationForQualityIncreaseMs = minDurationForQualityIncreaseMs;
       this.maxDurationForQualityDecreaseMs = maxDurationForQualityDecreaseMs;
       this.minDurationToRetainAfterDiscardMs = minDurationToRetainAfterDiscardMs;
@@ -147,7 +141,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
           group,
           tracks,
           bandwidthMeter,
-          maxInitialBitrate,
           minDurationForQualityIncreaseMs,
           maxDurationForQualityDecreaseMs,
           minDurationToRetainAfterDiscardMs,
@@ -156,10 +149,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
           minTimeBetweenBufferReevaluationMs,
           clock);
     }
-
   }
 
-  public static final int DEFAULT_MAX_INITIAL_BITRATE = 800000;
   public static final int DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS = 10000;
   public static final int DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS = 25000;
   public static final int DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS = 25000;
@@ -168,7 +159,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
   public static final long DEFAULT_MIN_TIME_BETWEEN_BUFFER_REEVALUTATION_MS = 2000;
 
   private final BandwidthMeter bandwidthMeter;
-  private final int maxInitialBitrate;
   private final long minDurationForQualityIncreaseUs;
   private final long maxDurationForQualityDecreaseUs;
   private final long minDurationToRetainAfterDiscardUs;
@@ -194,7 +184,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         group,
         tracks,
         bandwidthMeter,
-        DEFAULT_MAX_INITIAL_BITRATE,
         DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
         DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
         DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
@@ -209,8 +198,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
    * @param tracks The indices of the selected tracks within the {@link TrackGroup}. Must not be
    *     empty. May be in any order.
    * @param bandwidthMeter Provides an estimate of the currently available bandwidth.
-   * @param maxInitialBitrate The maximum bitrate in bits per second that should be assumed when a
-   *     bandwidth estimate is unavailable.
    * @param minDurationForQualityIncreaseMs The minimum duration of buffered data required for the
    *     selected track to switch to one of higher quality.
    * @param maxDurationForQualityDecreaseMs The maximum duration of buffered data required for the
@@ -237,7 +224,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
       TrackGroup group,
       int[] tracks,
       BandwidthMeter bandwidthMeter,
-      int maxInitialBitrate,
       long minDurationForQualityIncreaseMs,
       long maxDurationForQualityDecreaseMs,
       long minDurationToRetainAfterDiscardMs,
@@ -247,7 +233,6 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
       Clock clock) {
     super(group, tracks);
     this.bandwidthMeter = bandwidthMeter;
-    this.maxInitialBitrate = maxInitialBitrate;
     this.minDurationForQualityIncreaseUs = minDurationForQualityIncreaseMs * 1000L;
     this.maxDurationForQualityDecreaseUs = maxDurationForQualityDecreaseMs * 1000L;
     this.minDurationToRetainAfterDiscardUs = minDurationToRetainAfterDiscardMs * 1000L;
@@ -369,9 +354,7 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
    *     Long#MIN_VALUE} to ignore blacklisting.
    */
   private int determineIdealSelectedIndex(long nowMs) {
-    long bitrateEstimate = bandwidthMeter.getBitrateEstimate();
+    long effectiveBitrate = (long) (bandwidthMeter.getBitrateEstimate() * bandwidthFraction);
-    long effectiveBitrate = bitrateEstimate == BandwidthMeter.NO_ESTIMATE
-        ? maxInitialBitrate : (long) (bitrateEstimate * bandwidthFraction);
     int lowestBitrateNonBlacklistedIndex = 0;
     for (int i = 0; i < length; i++) {
       if (nowMs == Long.MIN_VALUE || !isBlacklisted(i, nowMs)) {
@@ -393,5 +376,4 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         ? (long) (availableDurationUs * bufferedFractionToLiveEdgeForQualityIncrease)
         : minDurationForQualityIncreaseUs;
   }
-
 }

library/core/src/main/java/com/google/android/exoplayer2/upstream/BandwidthMeter.java

@@ -27,28 +27,17 @@ public interface BandwidthMeter {
 
     /**
      * Called periodically to indicate that bytes have been transferred.
-     * <p>
+     *
-     * Note: The estimated bitrate is typically derived from more information than just
+     * <p>Note: The estimated bitrate is typically derived from more information than just {@code
-     * {@code bytes} and {@code elapsedMs}.
+     * bytes} and {@code elapsedMs}.
      *
      * @param elapsedMs The time taken to transfer the bytes, in milliseconds.
      * @param bytes The number of bytes transferred.
-     * @param bitrate The estimated bitrate in bits/sec, or {@link #NO_ESTIMATE} if an estimate is
+     * @param bitrate The estimated bitrate in bits/sec.
-     *     not available.
      */
     void onBandwidthSample(int elapsedMs, long bytes, long bitrate);
-
   }
 
-  /**
+  /** Returns the estimated bandwidth in bits/sec. */
-   * Indicates no bandwidth estimate is available.
-   */
-  long NO_ESTIMATE = -1;
-
-  /**
-   * Returns the estimated bandwidth in bits/sec, or {@link #NO_ESTIMATE} if an estimate is not
-   * available.
-   */
   long getBitrateEstimate();
-
 }

library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java

@@ -28,7 +28,7 @@ import com.google.android.exoplayer2.util.SlidingPercentile;
 public final class DefaultBandwidthMeter implements BandwidthMeter, TransferListener<Object> {
 
   /** Default initial bitrate estimate in bits per second. */
-  public static final long DEFAULT_INITIAL_BITRATE_ESTIMATE = BandwidthMeter.NO_ESTIMATE;
+  public static final long DEFAULT_INITIAL_BITRATE_ESTIMATE = 1_000_000;
 
   /** Default maximum weight for the sliding window. */
   public static final int DEFAULT_SLIDING_WINDOW_MAX_WEIGHT = 2000;

library/core/src/test/java/com/google/android/exoplayer2/trackselection/AdaptiveTrackSelectionTest.java

@@ -52,7 +52,6 @@ public final class AdaptiveTrackSelectionTest {
   public void setUp() {
     initMocks(this);
     fakeClock = new FakeClock(0);
-    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(BandwidthMeter.NO_ESTIMATE);
   }
 
   @Test
@@ -62,7 +61,8 @@ public final class AdaptiveTrackSelectionTest {
     Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
-    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup, /* initialBitrate= */ 1000);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(1000L);
+    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup);
 
     assertThat(adaptiveTrackSelection.getSelectedFormat()).isEqualTo(format2);
     assertThat(adaptiveTrackSelection.getSelectionReason()).isEqualTo(C.SELECTION_REASON_INITIAL);
@@ -76,8 +76,7 @@ public final class AdaptiveTrackSelectionTest {
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
     when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(500L);
-
+    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup);
-    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup, /* initialBitrate= */ 1000);
 
     assertThat(adaptiveTrackSelection.getSelectedFormat()).isEqualTo(format1);
     assertThat(adaptiveTrackSelection.getSelectionReason()).isEqualTo(C.SELECTION_REASON_INITIAL);
@@ -90,13 +89,12 @@ public final class AdaptiveTrackSelectionTest {
     Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
-    // initially bandwidth meter does not have any estimation. The second measurement onward returns
+    // The second measurement onward returns 2000L, which prompts the track selection to switch up
-    // 2000L, which prompts the track selection to switch up if possible.
+    // if possible.
-    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(BandwidthMeter.NO_ESTIMATE, 2000L);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(1000L, 2000L);
-
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMinDurationForQualityIncreaseMs(
-            trackGroup, /* initialBitrate= */ 1000, /* minDurationForQualityIncreaseMs= */ 10_000);
+            trackGroup, /* minDurationForQualityIncreaseMs= */ 10_000);
 
     adaptiveTrackSelection.updateSelectedTrack(
         /* playbackPositionUs= */ 0,
@@ -117,13 +115,12 @@ public final class AdaptiveTrackSelectionTest {
     Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
-    // initially bandwidth meter does not have any estimation. The second measurement onward returns
+    // The second measurement onward returns 2000L, which prompts the track selection to switch up
-    // 2000L, which prompts the track selection to switch up if possible.
+    // if possible.
-    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(BandwidthMeter.NO_ESTIMATE, 2000L);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(1000L, 2000L);
-
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMinDurationForQualityIncreaseMs(
-            trackGroup, /* initialBitrate= */ 1000, /* minDurationForQualityIncreaseMs= */ 10_000);
+            trackGroup, /* minDurationForQualityIncreaseMs= */ 10_000);
 
     adaptiveTrackSelection.updateSelectedTrack(
         /* playbackPositionUs= */ 0,
@@ -144,13 +141,12 @@ public final class AdaptiveTrackSelectionTest {
     Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
-    // initially bandwidth meter does not have any estimation. The second measurement onward returns
+    // The second measurement onward returns 500L, which prompts the track selection to switch down
-    // 500L, which prompts the track selection to switch down if necessary.
+    // if necessary.
-    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(BandwidthMeter.NO_ESTIMATE, 500L);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(1000L, 500L);
-
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMaxDurationForQualityDecreaseMs(
-            trackGroup, /* initialBitrate= */ 1000, /* maxDurationForQualityDecreaseMs= */ 25_000);
+            trackGroup, /* maxDurationForQualityDecreaseMs= */ 25_000);
 
     adaptiveTrackSelection.updateSelectedTrack(
         /* playbackPositionUs= */ 0,
@@ -171,13 +167,12 @@ public final class AdaptiveTrackSelectionTest {
     Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
     TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
 
-    // initially bandwidth meter does not have any estimation. The second measurement onward returns
+    // The second measurement onward returns 500L, which prompts the track selection to switch down
-    // 500L, which prompts the track selection to switch down if necessary.
+    // if necessary.
-    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(BandwidthMeter.NO_ESTIMATE, 500L);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(1000L, 500L);
-
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMaxDurationForQualityDecreaseMs(
-            trackGroup, /* initialBitrate= */ 1000, /* maxDurationForQualityDecreaseMs= */ 25_000);
+            trackGroup, /* maxDurationForQualityDecreaseMs= */ 25_000);
 
     adaptiveTrackSelection.updateSelectedTrack(
         /* playbackPositionUs= */ 0,
@@ -210,7 +205,7 @@ public final class AdaptiveTrackSelectionTest {
     queue.add(chunk3);
 
     when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(500L);
-    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup, /* initialBitrate= */ 1000);
+    adaptiveTrackSelection = adaptiveTrackSelection(trackGroup);
 
     int size = adaptiveTrackSelection.evaluateQueueSize(0, queue);
     assertThat(size).isEqualTo(3);
@@ -238,7 +233,6 @@ public final class AdaptiveTrackSelectionTest {
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMinTimeBetweenBufferReevaluationMs(
             trackGroup,
-            /* initialBitrate= */ 1000,
             /* durationToRetainAfterDiscardMs= */ 15_000,
             /* minTimeBetweenBufferReevaluationMs= */ 2000);
 
@@ -276,7 +270,6 @@ public final class AdaptiveTrackSelectionTest {
     adaptiveTrackSelection =
         adaptiveTrackSelectionWithMinTimeBetweenBufferReevaluationMs(
             trackGroup,
-            /* initialBitrate= */ 1000,
             /* durationToRetainAfterDiscardMs= */ 15_000,
             /* minTimeBetweenBufferReevaluationMs= */ 2000);
 
@@ -294,12 +287,11 @@ public final class AdaptiveTrackSelectionTest {
     assertThat(newSize).isEqualTo(2);
   }
 
-  private AdaptiveTrackSelection adaptiveTrackSelection(TrackGroup trackGroup, int initialBitrate) {
+  private AdaptiveTrackSelection adaptiveTrackSelection(TrackGroup trackGroup) {
     return new AdaptiveTrackSelection(
         trackGroup,
         selectedAllTracksInGroup(trackGroup),
         mockBandwidthMeter,
-        initialBitrate,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
         AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
@@ -310,12 +302,11 @@ public final class AdaptiveTrackSelectionTest {
   }
 
   private AdaptiveTrackSelection adaptiveTrackSelectionWithMinDurationForQualityIncreaseMs(
-      TrackGroup trackGroup, int initialBitrate, long minDurationForQualityIncreaseMs) {
+      TrackGroup trackGroup, long minDurationForQualityIncreaseMs) {
     return new AdaptiveTrackSelection(
         trackGroup,
         selectedAllTracksInGroup(trackGroup),
         mockBandwidthMeter,
-        initialBitrate,
         minDurationForQualityIncreaseMs,
         AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
@@ -326,12 +317,11 @@ public final class AdaptiveTrackSelectionTest {
   }
 
   private AdaptiveTrackSelection adaptiveTrackSelectionWithMaxDurationForQualityDecreaseMs(
-      TrackGroup trackGroup, int initialBitrate, long maxDurationForQualityDecreaseMs) {
+      TrackGroup trackGroup, long maxDurationForQualityDecreaseMs) {
     return new AdaptiveTrackSelection(
         trackGroup,
         selectedAllTracksInGroup(trackGroup),
         mockBandwidthMeter,
-        initialBitrate,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
         maxDurationForQualityDecreaseMs,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
@@ -343,18 +333,16 @@ public final class AdaptiveTrackSelectionTest {
 
   private AdaptiveTrackSelection adaptiveTrackSelectionWithMinTimeBetweenBufferReevaluationMs(
       TrackGroup trackGroup,
-      int initialBitrate,
       long durationToRetainAfterDiscardMs,
       long minTimeBetweenBufferReevaluationMs) {
     return new AdaptiveTrackSelection(
         trackGroup,
         selectedAllTracksInGroup(trackGroup),
         mockBandwidthMeter,
-        initialBitrate,
         AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
         AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
         durationToRetainAfterDiscardMs,
-        /* bandwidth fraction= */ 1.0f,
+        /* bandwidthFraction= */ 1.0f,
         AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
         minTimeBetweenBufferReevaluationMs,
         fakeClock);