Add the options for the maximum resolution values for which the selector may choose to discard when switching up to a higher quality

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

@@ -53,6 +53,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
     private final int minDurationForQualityIncreaseMs;
     private final int maxDurationForQualityDecreaseMs;
     private final int minDurationToRetainAfterDiscardMs;
+    private final int maxWidthToDiscard;
+    private final int maxHeightToDiscard;
     private final float bandwidthFraction;
     private final float bufferedFractionToLiveEdgeForQualityIncrease;
     private final Clock clock;
@@ -63,6 +65,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
           DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
           DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
           DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
+          DEFAULT_MAX_WIDTH_TO_DISCARD,
+          DEFAULT_MAX_HEIGHT_TO_DISCARD,
           DEFAULT_BANDWIDTH_FRACTION,
           DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
           Clock.DEFAULT);
@@ -80,6 +84,10 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
      *     be discarded to speed up the switch. This is the minimum duration of media that must be
      *     retained at the lower quality. It must be at least {@code
      *     minDurationForQualityIncreaseMs}.
+     * @param maxWidthToDiscard This is the maximum width for which the selector may choose to
+     *     discard when switching up to a higher quality.
+     * @param maxHeightToDiscard This is the maximum height for which the selector may choose to
+     *     discard when switching up to a higher 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 for
      *     inaccuracies in the bandwidth estimator.
@@ -88,11 +96,15 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         int minDurationForQualityIncreaseMs,
         int maxDurationForQualityDecreaseMs,
         int minDurationToRetainAfterDiscardMs,
+        int maxWidthToDiscard,
+        int maxHeightToDiscard,
         float bandwidthFraction) {
       this(
           minDurationForQualityIncreaseMs,
           maxDurationForQualityDecreaseMs,
           minDurationToRetainAfterDiscardMs,
+          maxWidthToDiscard,
+          maxHeightToDiscard,
           bandwidthFraction,
           DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
           Clock.DEFAULT);
@@ -110,6 +122,10 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
      *     be discarded to speed up the switch. This is the minimum duration of media that must be
      *     retained at the lower quality. It must be at least {@code
      *     minDurationForQualityIncreaseMs}.
+     * @param maxWidthToDiscard This is the maximum width for which the selector may choose to
+     *     discard when switching up to a higher quality.
+     * @param maxHeightToDiscard This is the maximum height for which the selector may choose to
+     *     discard when switching up to a higher 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 for
      *     inaccuracies in the bandwidth estimator.
@@ -125,12 +141,16 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         int minDurationForQualityIncreaseMs,
         int maxDurationForQualityDecreaseMs,
         int minDurationToRetainAfterDiscardMs,
+        int maxWidthToDiscard,
+        int maxHeightToDiscard,
         float bandwidthFraction,
         float bufferedFractionToLiveEdgeForQualityIncrease,
         Clock clock) {
       this.minDurationForQualityIncreaseMs = minDurationForQualityIncreaseMs;
       this.maxDurationForQualityDecreaseMs = maxDurationForQualityDecreaseMs;
       this.minDurationToRetainAfterDiscardMs = minDurationToRetainAfterDiscardMs;
+      this.maxWidthToDiscard = maxWidthToDiscard;
+      this.maxHeightToDiscard = maxHeightToDiscard;
       this.bandwidthFraction = bandwidthFraction;
       this.bufferedFractionToLiveEdgeForQualityIncrease =
           bufferedFractionToLiveEdgeForQualityIncrease;
@@ -192,6 +212,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
           minDurationForQualityIncreaseMs,
           maxDurationForQualityDecreaseMs,
           minDurationToRetainAfterDiscardMs,
+          maxWidthToDiscard,
+          maxHeightToDiscard,
           bandwidthFraction,
           bufferedFractionToLiveEdgeForQualityIncrease,
           adaptationCheckpoints,
@@ -202,6 +224,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
   public static final int DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS = 10_000;
   public static final int DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS = 25_000;
   public static final int DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS = 25_000;
+  public static final int DEFAULT_MAX_WIDTH_TO_DISCARD = 1279;
+  public static final int DEFAULT_MAX_HEIGHT_TO_DISCARD = 719;
   public static final float DEFAULT_BANDWIDTH_FRACTION = 0.7f;
   public static final float DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE = 0.75f;
 
@@ -211,6 +235,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
   private final long minDurationForQualityIncreaseUs;
   private final long maxDurationForQualityDecreaseUs;
   private final long minDurationToRetainAfterDiscardUs;
+  private final int maxWidthToDiscard;
+  private final int maxHeightToDiscard;
   private final float bandwidthFraction;
   private final float bufferedFractionToLiveEdgeForQualityIncrease;
   private final ImmutableList<AdaptationCheckpoint> adaptationCheckpoints;
@@ -237,6 +263,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
         DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
         DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
         DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
+        DEFAULT_MAX_WIDTH_TO_DISCARD,
+        DEFAULT_MAX_HEIGHT_TO_DISCARD,
         DEFAULT_BANDWIDTH_FRACTION,
         DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
         /* adaptationCheckpoints= */ ImmutableList.of(),
@@ -257,6 +285,10 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
    *     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. It must be at least {@code minDurationForQualityIncreaseMs}.
+   * @param maxWidthToDiscard This is the maximum width for which the selector may choose to
+   *     discard when switching up to a higher quality.
+   * @param maxHeightToDiscard This is the maximum height for which the selector may choose to
+   *     discard when switching up to a higher 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 for
    *     inaccuracies in the bandwidth estimator.
@@ -278,6 +310,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
       long minDurationForQualityIncreaseMs,
       long maxDurationForQualityDecreaseMs,
       long minDurationToRetainAfterDiscardMs,
+      int maxWidthToDiscard,
+      int maxHeightToDiscard,
       float bandwidthFraction,
       float bufferedFractionToLiveEdgeForQualityIncrease,
       List<AdaptationCheckpoint> adaptationCheckpoints,
@@ -294,6 +328,8 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
     this.minDurationForQualityIncreaseUs = minDurationForQualityIncreaseMs * 1000L;
     this.maxDurationForQualityDecreaseUs = maxDurationForQualityDecreaseMs * 1000L;
     this.minDurationToRetainAfterDiscardUs = minDurationToRetainAfterDiscardMs * 1000L;
+    this.maxWidthToDiscard = maxWidthToDiscard;
+    this.maxHeightToDiscard = maxHeightToDiscard;
     this.bandwidthFraction = bandwidthFraction;
     this.bufferedFractionToLiveEdgeForQualityIncrease =
         bufferedFractionToLiveEdgeForQualityIncrease;
@@ -410,9 +446,9 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
     }
     int idealSelectedIndex = determineIdealSelectedIndex(nowMs, getLastChunkDurationUs(queue));
     Format idealFormat = getFormat(idealSelectedIndex);
-    // If the chunks contain video, discard from the first SD chunk beyond
+    // If the chunks contain video, discard from the first chunk less than or equal to
-    // minDurationToRetainAfterDiscardUs whose resolution and bitrate are both lower than the ideal
+    // maxWidthToDiscard and maxHeightToDiscard beyond minDurationToRetainAfterDiscardUs
-    // track.
+    // whose resolution and bitrate are both lower than the ideal track.
     for (int i = 0; i < queueSize; i++) {
       MediaChunk chunk = queue.get(i);
       Format format = chunk.trackFormat;
@@ -422,9 +458,9 @@ public class AdaptiveTrackSelection extends BaseTrackSelection {
       if (playoutDurationBeforeThisChunkUs >= minDurationToRetainAfterDiscardUs
           && format.bitrate < idealFormat.bitrate
           && format.height != Format.NO_VALUE
-          && format.height < 720
+          && format.height <= maxHeightToDiscard
           && format.width != Format.NO_VALUE
-          && format.width < 1280
+          && format.width <= maxWidthToDiscard
           && format.height < idealFormat.height) {
         return i;
       }

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

@@ -321,6 +321,52 @@ public final class AdaptiveTrackSelectionTest {
     assertThat(newSize).isEqualTo(2);
   }
 
+  @Test
+  public void evaluateQueueSizeDiscardChunksLessThanOrEqualToMaximumResolution() {
+    Format format1 = videoFormat(/* bitrate= */ 500, /* width= */ 320, /* height= */ 240);
+    Format format2 = videoFormat(/* bitrate= */ 1000, /* width= */ 640, /* height= */ 480);
+    Format format3 = videoFormat(/* bitrate= */ 2000, /* width= */ 960, /* height= */ 720);
+    TrackGroup trackGroup = new TrackGroup(format1, format2, format3);
+
+    FakeMediaChunk chunk1 =
+        new FakeMediaChunk(format2, /* startTimeUs= */ 0, /* endTimeUs= */ 10_000_000);
+    FakeMediaChunk chunk2 =
+        new FakeMediaChunk(format2, /* startTimeUs= */ 10_000_000, /* endTimeUs= */ 20_000_000);
+    FakeMediaChunk chunk3 =
+        new FakeMediaChunk(format2, /* startTimeUs= */ 20_000_000, /* endTimeUs= */ 30_000_000);
+    FakeMediaChunk chunk4 =
+        new FakeMediaChunk(format2, /* startTimeUs= */ 30_000_000, /* endTimeUs= */ 40_000_000);
+    FakeMediaChunk chunk5 =
+        new FakeMediaChunk(format1, /* startTimeUs= */ 40_000_000, /* endTimeUs= */ 50_000_000);
+
+    List<FakeMediaChunk> queue = new ArrayList<>();
+    queue.add(chunk1);
+    queue.add(chunk2);
+    queue.add(chunk3);
+    queue.add(chunk4);
+    queue.add(chunk5);
+
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(500L);
+    AdaptiveTrackSelection adaptiveTrackSelection =
+        prepareAdaptiveTrackSelectionWithMaxResolutionToDiscard(
+            trackGroup,
+            /* maxWidthToDiscard= */320,
+            /* maxHeightToDiscard= */240
+        );
+
+    int initialQueueSize = adaptiveTrackSelection.evaluateQueueSize(0, queue);
+    assertThat(initialQueueSize).isEqualTo(5);
+
+    fakeClock.advanceTime(2000);
+    when(mockBandwidthMeter.getBitrateEstimate()).thenReturn(2000L);
+
+    // When bandwidth estimation is updated and time has advanced enough, we can discard chunks at
+    // the end of the queue now.
+    // In this case, only chunks less than or equal to width = 320 and height = 240 are discarded.
+    int newSize = adaptiveTrackSelection.evaluateQueueSize(0, queue);
+    assertThat(newSize).isEqualTo(4);
+  }
+
   @Test
   public void updateSelectedTrack_usesFormatOfLastChunkInTheQueueForSelection() {
     Format format1 = videoFormat(/* bitrate= */ 500, /* width= */ 320, /* height= */ 240);
@@ -331,6 +377,8 @@ public final class AdaptiveTrackSelectionTest {
                 /* minDurationForQualityIncreaseMs= */ 10_000,
                 /* maxDurationForQualityDecreaseMs= */ 10_000,
                 /* minDurationToRetainAfterDiscardMs= */ 25_000,
+                /* maxWidthToDiscard= */ 1279,
+                /* maxHeightToDiscard= */ 719,
                 /* bandwidthFraction= */ 1f)
             .createAdaptiveTrackSelection(
                 trackGroup,
@@ -616,6 +664,8 @@ public final class AdaptiveTrackSelectionTest {
             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,
+            AdaptiveTrackSelection.DEFAULT_MAX_WIDTH_TO_DISCARD,
+            AdaptiveTrackSelection.DEFAULT_MAX_HEIGHT_TO_DISCARD,
             bandwidthFraction,
             AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
             /* adaptationCheckpoints= */ ImmutableList.of(),
@@ -633,6 +683,8 @@ public final class AdaptiveTrackSelectionTest {
             minDurationForQualityIncreaseMs,
             AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
             AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
+            AdaptiveTrackSelection.DEFAULT_MAX_WIDTH_TO_DISCARD,
+            AdaptiveTrackSelection.DEFAULT_MAX_HEIGHT_TO_DISCARD,
             /* bandwidthFraction= */ 1.0f,
             AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
             /* adaptationCheckpoints= */ ImmutableList.of(),
@@ -650,6 +702,8 @@ public final class AdaptiveTrackSelectionTest {
             AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
             maxDurationForQualityDecreaseMs,
             AdaptiveTrackSelection.DEFAULT_MIN_DURATION_TO_RETAIN_AFTER_DISCARD_MS,
+            AdaptiveTrackSelection.DEFAULT_MAX_WIDTH_TO_DISCARD,
+            AdaptiveTrackSelection.DEFAULT_MAX_HEIGHT_TO_DISCARD,
             /* bandwidthFraction= */ 1.0f,
             AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
             /* adaptationCheckpoints= */ ImmutableList.of(),
@@ -668,6 +722,30 @@ public final class AdaptiveTrackSelectionTest {
             AdaptiveTrackSelection.DEFAULT_MIN_DURATION_FOR_QUALITY_INCREASE_MS,
             AdaptiveTrackSelection.DEFAULT_MAX_DURATION_FOR_QUALITY_DECREASE_MS,
             durationToRetainAfterDiscardMs,
+            AdaptiveTrackSelection.DEFAULT_MAX_WIDTH_TO_DISCARD,
+            AdaptiveTrackSelection.DEFAULT_MAX_HEIGHT_TO_DISCARD,
+            /* bandwidthFraction= */ 1.0f,
+            AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
+            /* adaptationCheckpoints= */ ImmutableList.of(),
+            fakeClock));
+  }
+
+  private AdaptiveTrackSelection
+  prepareAdaptiveTrackSelectionWithMaxResolutionToDiscard(
+      TrackGroup trackGroup,
+      int maxWidthToDiscard,
+      int maxHeightToDiscard) {
+    return prepareTrackSelection(
+        new AdaptiveTrackSelection(
+            trackGroup,
+            selectedAllTracksInGroup(trackGroup),
+            TrackSelection.TYPE_UNSET,
+            mockBandwidthMeter,
+            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,
+            maxWidthToDiscard,
+            maxHeightToDiscard,
             /* bandwidthFraction= */ 1.0f,
             AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
             /* adaptationCheckpoints= */ ImmutableList.of(),
@@ -685,6 +763,8 @@ public final class AdaptiveTrackSelectionTest {
             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,
+            AdaptiveTrackSelection.DEFAULT_MAX_WIDTH_TO_DISCARD,
+            AdaptiveTrackSelection.DEFAULT_MAX_HEIGHT_TO_DISCARD,
             /* bandwidthFraction= */ 1.0f,
             AdaptiveTrackSelection.DEFAULT_BUFFERED_FRACTION_TO_LIVE_EDGE_FOR_QUALITY_INCREASE,
             adaptationCheckpoints,