Ensure implicit manifest updates arrives asap

PiperOrigin-RevId: 333714978

Ensure implicit manifest updates arrives asap
PiperOrigin-RevId: 333714978
c107017a · bachinger · kim-vde · 397fe8f3 · c107017a · c107017a
Commit c107017a authored Sep 25, 2020 by bachinger Committed by kim-vde Sep 25, 2020
Showing with 287 additions and 151 deletions
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashSegmentIndex.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashWrappingSegmentIndex.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/Representation.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SegmentBase.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SingleSegmentIndex.java
--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java
@@ -50,6 +50,8 @@ import com.google.android.exoplayer2.source.dash.PlayerEmsgHandler.PlayerEmsgCal
 import com.google.android.exoplayer2.source.dash.manifest.AdaptationSet;
 import com.google.android.exoplayer2.source.dash.manifest.DashManifest;
 import com.google.android.exoplayer2.source.dash.manifest.DashManifestParser;
+import com.google.android.exoplayer2.source.dash.manifest.Period;
+import com.google.android.exoplayer2.source.dash.manifest.Representation;
 import com.google.android.exoplayer2.source.dash.manifest.UtcTimingElement;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
@@ -68,10 +70,12 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.SntpClient;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Charsets;
+import com.google.common.math.LongMath;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.math.RoundingMode;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Collections;
@@ -441,7 +445,7 @@ public final class DashMediaSource extends BaseMediaSource {
   * MediaSourceCaller#onSourceInfoRefreshed(MediaSource, Timeline)} when the source's {@link
   * Timeline} is changing dynamically (for example, for incomplete live streams).
   */
-  private static final int NOTIFY_MANIFEST_INTERVAL_MS = 5000;
+  private static final long DEFAULT_NOTIFY_MANIFEST_INTERVAL_MS = 5000;
  /**
   * The minimum default start position for live streams, relative to the start of the live window.
   */
@@ -1106,7 +1110,10 @@ public final class DashMediaSource extends BaseMediaSource {
      handler.removeCallbacks(simulateManifestRefreshRunnable);
      // If the window is changing implicitly, post a simulated manifest refresh to update it.
      if (windowChangingImplicitly) {
-        handler.postDelayed(simulateManifestRefreshRunnable, NOTIFY_MANIFEST_INTERVAL_MS);
+        handler.postDelayed(
+            simulateManifestRefreshRunnable,
+            getIntervalUntilNextManifestRefreshMs(
+                manifest, Util.getNowUnixTimeMs(elapsedRealtimeOffsetMs)));
      }
      if (manifestLoadPending) {
        startLoadingManifest();
@@ -1165,6 +1172,38 @@ public final class DashMediaSource extends BaseMediaSource {
        loadable.type);
  }
+  private static long getIntervalUntilNextManifestRefreshMs(
+      DashManifest manifest, long nowUnixTimeMs) {
+    int periodIndex = manifest.getPeriodCount() - 1;
+    Period period = manifest.getPeriod(periodIndex);
+    long periodStartUs = C.msToUs(period.startMs);
+    long periodDurationUs = manifest.getPeriodDurationUs(periodIndex);
+    long nowUnixTimeUs = C.msToUs(nowUnixTimeMs);
+    long availabilityStartTimeUs = C.msToUs(manifest.availabilityStartTimeMs);
+    long intervalUs = C.msToUs(DEFAULT_NOTIFY_MANIFEST_INTERVAL_MS);
+    for (int i = 0; i < period.adaptationSets.size(); i++) {
+      List<Representation> representations = period.adaptationSets.get(i).representations;
+      if (representations.isEmpty()) {
+        continue;
+      }
+      @Nullable DashSegmentIndex index = representations.get(0).getIndex();
+      if (index != null) {
+        long nextSegmentShiftUnixTimeUs =
+            availabilityStartTimeUs
+                + periodStartUs
+                + index.getNextSegmentAvailableTimeUs(periodDurationUs, nowUnixTimeUs);
+        long requiredIntervalUs = nextSegmentShiftUnixTimeUs - nowUnixTimeUs;
+        // Avoid multiple refreshes within a very small amount of time.
+        if (requiredIntervalUs < intervalUs - 100_000
+            || (requiredIntervalUs > intervalUs && requiredIntervalUs < intervalUs + 100_000)) {
+          intervalUs = requiredIntervalUs;
+        }
+      }
+    }
+    // Round up to compensate for a potential loss in the us to ms conversion.
+    return LongMath.divide(intervalUs, 1000, RoundingMode.CEILING);
+  }
  private static final class PeriodSeekInfo {
    public static PeriodSeekInfo createPeriodSeekInfo(

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashSegmentIndex.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashSegmentIndex.java
@@ -102,6 +102,18 @@ public interface DashSegmentIndex {
  int getAvailableSegmentCount(long periodDurationUs, long nowUnixTimeUs);
  /**
+   * Returns the time, in microseconds, at which a new segment becomes available, or {@link
+   * C#TIME_UNSET} if not applicable.
+   *
+   * @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
+   *     C#TIME_UNSET} if the period's duration is not yet known.
+   * @param nowUnixTimeUs The current time in milliseconds since the Unix epoch.
+   * @return The time, in microseconds, at which a new segment becomes available, or {@link
+   *     C#TIME_UNSET} if not applicable.
+   */
+  long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs);
+  /**
   * Returns true if segments are defined explicitly by the index.
   *
   * <p>If true is returned, each segment is defined explicitly by the index data, and all of the

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashWrappingSegmentIndex.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashWrappingSegmentIndex.java
@@ -15,6 +15,7 @@
 */
 package com.google.android.exoplayer2.source.dash;
+import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.extractor.ChunkIndex;
 import com.google.android.exoplayer2.source.dash.manifest.RangedUri;
@@ -57,6 +58,11 @@ public final class DashWrappingSegmentIndex implements DashSegmentIndex {
  }
  @Override
+  public long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs) {
+    return C.TIME_UNSET;
+  }
+  @Override
  public long getTimeUs(long segmentNum) {
    return chunkIndex.timesUs[(int) segmentNum] - timeOffsetUs;
  }

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java
@@ -291,9 +291,11 @@ public class DashManifestParser extends DefaultHandler
            parseSegmentList(
                xpp,
                /* parent= */ null,
+                periodStartUnixTimeMs,
                durationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "SegmentTemplate")) {
        segmentBaseAvailabilityTimeOffsetUs =
            parseAvailabilityTimeOffsetUs(xpp, /* parentAvailabilityTimeOffsetUs= */ C.TIME_UNSET);
@@ -302,9 +304,11 @@ public class DashManifestParser extends DefaultHandler
                xpp,
                /* parent= */ null,
                ImmutableList.of(),
+                periodStartUnixTimeMs,
                durationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "AssetIdentifier")) {
        assetIdentifier = parseDescriptor(xpp, "AssetIdentifier");
      } else {
@@ -407,9 +411,11 @@ public class DashManifestParser extends DefaultHandler
                essentialProperties,
                supplementalProperties,
                segmentBase,
+                periodStartUnixTimeMs,
                periodDurationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
        contentType =
            checkContentTypeConsistency(
                contentType, MimeTypes.getTrackType(representationInfo.format.sampleMimeType));
@@ -423,9 +429,11 @@ public class DashManifestParser extends DefaultHandler
            parseSegmentList(
                xpp,
                (SegmentList) segmentBase,
+                periodStartUnixTimeMs,
                periodDurationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "SegmentTemplate")) {
        segmentBaseAvailabilityTimeOffsetUs =
            parseAvailabilityTimeOffsetUs(xpp, segmentBaseAvailabilityTimeOffsetUs);
@@ -434,9 +442,11 @@ public class DashManifestParser extends DefaultHandler
                xpp,
                (SegmentTemplate) segmentBase,
                supplementalProperties,
+                periodStartUnixTimeMs,
                periodDurationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "InbandEventStream")) {
        inbandEventStreams.add(parseDescriptor(xpp, "InbandEventStream"));
      } else if (XmlPullParserUtil.isStartTag(xpp, "Label")) {
@@ -455,9 +465,7 @@ public class DashManifestParser extends DefaultHandler
              label,
              drmSchemeType,
              drmSchemeDatas,
-              inbandEventStreams,
+              inbandEventStreams));
-              periodStartUnixTimeMs,
-              timeShiftBufferDepthMs));
    }
    return buildAdaptationSet(
@@ -599,9 +607,11 @@ public class DashManifestParser extends DefaultHandler
      List<Descriptor> adaptationSetEssentialProperties,
      List<Descriptor> adaptationSetSupplementalProperties,
      @Nullable SegmentBase segmentBase,
+      long periodStartUnixTimeMs,
      long periodDurationMs,
      long baseUrlAvailabilityTimeOffsetUs,
-      long segmentBaseAvailabilityTimeOffsetUs)
+      long segmentBaseAvailabilityTimeOffsetUs,
+      long timeShiftBufferDepthMs)
      throws XmlPullParserException, IOException {
    String id = xpp.getAttributeValue(null, "id");
    int bandwidth = parseInt(xpp, "bandwidth", Format.NO_VALUE);
@@ -641,9 +651,11 @@ public class DashManifestParser extends DefaultHandler
            parseSegmentList(
                xpp,
                (SegmentList) segmentBase,
+                periodStartUnixTimeMs,
                periodDurationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "SegmentTemplate")) {
        segmentBaseAvailabilityTimeOffsetUs =
            parseAvailabilityTimeOffsetUs(xpp, segmentBaseAvailabilityTimeOffsetUs);
@@ -652,9 +664,11 @@ public class DashManifestParser extends DefaultHandler
                xpp,
                (SegmentTemplate) segmentBase,
                adaptationSetSupplementalProperties,
+                periodStartUnixTimeMs,
                periodDurationMs,
                baseUrlAvailabilityTimeOffsetUs,
-                segmentBaseAvailabilityTimeOffsetUs);
+                segmentBaseAvailabilityTimeOffsetUs,
+                timeShiftBufferDepthMs);
      } else if (XmlPullParserUtil.isStartTag(xpp, "ContentProtection")) {
        Pair<String, SchemeData> contentProtection = parseContentProtection(xpp);
        if (contentProtection.first != null) {
@@ -754,9 +768,7 @@ public class DashManifestParser extends DefaultHandler
      @Nullable String label,
      @Nullable String extraDrmSchemeType,
      ArrayList<SchemeData> extraDrmSchemeDatas,
-      ArrayList<Descriptor> extraInbandEventStreams,
+      ArrayList<Descriptor> extraInbandEventStreams) {
-      long periodStartUnixTimeMs,
-      long timeShiftBufferDepthMs) {
    Format.Builder formatBuilder = representationInfo.format.buildUpon();
    if (label != null) {
      formatBuilder.setLabel(label);
@@ -778,9 +790,7 @@ public class DashManifestParser extends DefaultHandler
        formatBuilder.build(),
        representationInfo.baseUrl,
        representationInfo.segmentBase,
-        inbandEventStreams,
+        inbandEventStreams);
-        periodStartUnixTimeMs,
-        timeShiftBufferDepthMs);
  }
  // SegmentBase, SegmentList and SegmentTemplate parsing.
@@ -825,9 +835,11 @@ public class DashManifestParser extends DefaultHandler
  protected SegmentList parseSegmentList(
      XmlPullParser xpp,
      @Nullable SegmentList parent,
+      long periodStartUnixTimeMs,
      long periodDurationMs,
      long baseUrlAvailabilityTimeOffsetUs,
-      long segmentBaseAvailabilityTimeOffsetUs)
+      long segmentBaseAvailabilityTimeOffsetUs,
+      long timeShiftBufferDepthMs)
      throws XmlPullParserException, IOException {
    long timescale = parseLong(xpp, "timescale", parent != null ? parent.timescale : 1);
@@ -873,7 +885,9 @@ public class DashManifestParser extends DefaultHandler
        duration,
        timeline,
        availabilityTimeOffsetUs,
-        segments);
+        segments,
+        timeShiftBufferDepthMs,
+        periodStartUnixTimeMs);
  }
  protected SegmentList buildSegmentList(
@@ -884,7 +898,9 @@ public class DashManifestParser extends DefaultHandler
      long duration,
      @Nullable List<SegmentTimelineElement> timeline,
      long availabilityTimeOffsetUs,
-      @Nullable List<RangedUri> segments) {
+      @Nullable List<RangedUri> segments,
+      long timeShiftBufferDepthMs,
+      long periodStartUnixTimeMs) {
    return new SegmentList(
        initialization,
        timescale,
@@ -893,16 +909,20 @@ public class DashManifestParser extends DefaultHandler
        duration,
        timeline,
        availabilityTimeOffsetUs,
-        segments);
+        segments,
+        C.msToUs(timeShiftBufferDepthMs),
+        C.msToUs(periodStartUnixTimeMs));
  }
  protected SegmentTemplate parseSegmentTemplate(
      XmlPullParser xpp,
      @Nullable SegmentTemplate parent,
      List<Descriptor> adaptationSetSupplementalProperties,
+      long periodStartUnixTimeMs,
      long periodDurationMs,
      long baseUrlAvailabilityTimeOffsetUs,
-      long segmentBaseAvailabilityTimeOffsetUs)
+      long segmentBaseAvailabilityTimeOffsetUs,
+      long timeShiftBufferDepthMs)
      throws XmlPullParserException, IOException {
    long timescale = parseLong(xpp, "timescale", parent != null ? parent.timescale : 1);
    long presentationTimeOffset = parseLong(xpp, "presentationTimeOffset",
@@ -949,7 +969,9 @@ public class DashManifestParser extends DefaultHandler
        timeline,
        availabilityTimeOffsetUs,
        initializationTemplate,
-        mediaTemplate);
+        mediaTemplate,
+        timeShiftBufferDepthMs,
+        periodStartUnixTimeMs);
  }
  protected SegmentTemplate buildSegmentTemplate(
@@ -962,7 +984,9 @@ public class DashManifestParser extends DefaultHandler
      List<SegmentTimelineElement> timeline,
      long availabilityTimeOffsetUs,
      @Nullable UrlTemplate initializationTemplate,
-      @Nullable UrlTemplate mediaTemplate) {
+      @Nullable UrlTemplate mediaTemplate,
+      long timeShiftBufferDepthMs,
+      long periodStartUnixTimeMs) {
    return new SegmentTemplate(
        initialization,
        timescale,
@@ -973,7 +997,9 @@ public class DashManifestParser extends DefaultHandler
        timeline,
        availabilityTimeOffsetUs,
        initializationTemplate,
-        mediaTemplate);
+        mediaTemplate,
+        C.msToUs(timeShiftBufferDepthMs),
+        C.msToUs(periodStartUnixTimeMs));
  }
  /**

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/Representation.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/Representation.java
@@ -15,8 +15,6 @@
 */
 package com.google.android.exoplayer2.source.dash.manifest;
-import static java.lang.Math.max;
 import android.net.Uri;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
@@ -73,14 +71,7 @@ public abstract class Representation {
   */
  public static Representation newInstance(
      long revisionId, Format format, String baseUrl, SegmentBase segmentBase) {
-    return newInstance(
+    return newInstance(revisionId, format, baseUrl, segmentBase, /* inbandEventStreams= */ null);
-        revisionId,
-        format,
-        baseUrl,
-        segmentBase,
-        /* inbandEventStreams= */ null,
-        /* periodStartUnixTimeMs= */ C.TIME_UNSET,
-        /* timeShiftBufferDepthMs= */ C.TIME_UNSET);
  }
  /**
@@ -91,9 +82,6 @@ public abstract class Representation {
   * @param baseUrl The base URL.
   * @param segmentBase A segment base element for the representation.
   * @param inbandEventStreams The in-band event streams in the representation. May be null.
-   * @param periodStartUnixTimeMs The start time of the enclosing {@link Period} in milliseconds
-   *     since the Unix epoch, or {@link C#TIME_UNSET} is not applicable.
-   * @param timeShiftBufferDepthMs The {@link DashManifest#timeShiftBufferDepthMs}.
   * @return The constructed instance.
   */
  public static Representation newInstance(
@@ -101,17 +89,13 @@ public abstract class Representation {
      Format format,
      String baseUrl,
      SegmentBase segmentBase,
-      @Nullable List<Descriptor> inbandEventStreams,
+      @Nullable List<Descriptor> inbandEventStreams) {
-      long periodStartUnixTimeMs,
-      long timeShiftBufferDepthMs) {
    return newInstance(
        revisionId,
        format,
        baseUrl,
        segmentBase,
        inbandEventStreams,
-        periodStartUnixTimeMs,
-        timeShiftBufferDepthMs,
        /* cacheKey= */ null);
  }
@@ -123,9 +107,6 @@ public abstract class Representation {
   * @param baseUrl The base URL of the representation.
   * @param segmentBase A segment base element for the representation.
   * @param inbandEventStreams The in-band event streams in the representation. May be null.
-   * @param periodStartUnixTimeMs The start time of the enclosing {@link Period} in milliseconds
-   *     since the Unix epoch, or {@link C#TIME_UNSET} is not applicable.
-   * @param timeShiftBufferDepthMs The {@link DashManifest#timeShiftBufferDepthMs}.
   * @param cacheKey An optional key to be returned from {@link #getCacheKey()}, or null. This
   *     parameter is ignored if {@code segmentBase} consists of multiple segments.
   * @return The constructed instance.
@@ -136,8 +117,6 @@ public abstract class Representation {
      String baseUrl,
      SegmentBase segmentBase,
      @Nullable List<Descriptor> inbandEventStreams,
-      long periodStartUnixTimeMs,
-      long timeShiftBufferDepthMs,
      @Nullable String cacheKey) {
    if (segmentBase instanceof SingleSegmentBase) {
      return new SingleSegmentRepresentation(
@@ -150,13 +129,7 @@ public abstract class Representation {
          C.LENGTH_UNSET);
    } else if (segmentBase instanceof MultiSegmentBase) {
      return new MultiSegmentRepresentation(
-          revisionId,
+          revisionId, format, baseUrl, (MultiSegmentBase) segmentBase, inbandEventStreams);
-          format,
-          baseUrl,
-          (MultiSegmentBase) segmentBase,
-          inbandEventStreams,
-          periodStartUnixTimeMs,
-          timeShiftBufferDepthMs);
    } else {
      throw new IllegalArgumentException("segmentBase must be of type SingleSegmentBase or "
          + "MultiSegmentBase");
@@ -309,8 +282,6 @@ public abstract class Representation {
      implements DashSegmentIndex {
    @VisibleForTesting /* package */ final MultiSegmentBase segmentBase;
-    private final long periodStartUnixTimeUs;
-    private final long timeShiftBufferDepthUs;
    /**
     * Creates the multi-segment Representation.
@@ -320,22 +291,15 @@ public abstract class Representation {
     * @param baseUrl The base URL of the representation.
     * @param segmentBase The segment base underlying the representation.
     * @param inbandEventStreams The in-band event streams in the representation. May be null.
-     * @param periodStartUnixTimeMs The start time of the enclosing {@link Period} in milliseconds
-     *     since the Unix epoch, or {@link C#TIME_UNSET} is not applicable.
-     * @param timeShiftBufferDepthMs The {@link DashManifest#timeShiftBufferDepthMs}.
     */
    public MultiSegmentRepresentation(
        long revisionId,
        Format format,
        String baseUrl,
        MultiSegmentBase segmentBase,
-        @Nullable List<Descriptor> inbandEventStreams,
+        @Nullable List<Descriptor> inbandEventStreams) {
-        long periodStartUnixTimeMs,
-        long timeShiftBufferDepthMs) {
      super(revisionId, format, baseUrl, segmentBase, inbandEventStreams);
      this.segmentBase = segmentBase;
-      this.periodStartUnixTimeUs = C.msToUs(periodStartUnixTimeMs);
-      this.timeShiftBufferDepthUs = C.msToUs(timeShiftBufferDepthMs);
    }
    @Override
@@ -384,17 +348,7 @@ public abstract class Representation {
    @Override
    public long getFirstAvailableSegmentNum(long periodDurationUs, long nowUnixTimeUs) {
-      long segmentCount = segmentBase.getSegmentCount(periodDurationUs);
+      return segmentBase.getFirstAvailableSegmentNum(periodDurationUs, nowUnixTimeUs);
-      if (segmentCount != INDEX_UNBOUNDED || timeShiftBufferDepthUs == C.TIME_UNSET) {
-        return segmentBase.getFirstSegmentNum();
-      }
-      // The index is itself unbounded. We need to use the current time to calculate the range of
-      // available segments.
-      long liveEdgeTimeInPeriodUs = nowUnixTimeUs - periodStartUnixTimeUs;
-      long timeShiftBufferStartInPeriodUs = liveEdgeTimeInPeriodUs - timeShiftBufferDepthUs;
-      long timeShiftBufferStartSegmentNum =
-          getSegmentNum(timeShiftBufferStartInPeriodUs, periodDurationUs);
-      return max(getFirstSegmentNum(), timeShiftBufferStartSegmentNum);
    }
    @Override
@@ -404,18 +358,12 @@ public abstract class Representation {
    @Override
    public int getAvailableSegmentCount(long periodDurationUs, long nowUnixTimeUs) {
-      int segmentCount = segmentBase.getSegmentCount(periodDurationUs);
+      return segmentBase.getAvailableSegmentCount(periodDurationUs, nowUnixTimeUs);
-      if (segmentCount != INDEX_UNBOUNDED) {
+    }
-        return segmentCount;
-      }
+    @Override
-      // The index is itself unbounded. We need to use the current time to calculate the range of
+    public long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs) {
-      // available segments.
+      return segmentBase.getNextSegmentAvailableTimeUs(periodDurationUs, nowUnixTimeUs);
-      long liveEdgeTimeInPeriodUs = nowUnixTimeUs - periodStartUnixTimeUs;
-      long availabilityEndTimeUs = liveEdgeTimeInPeriodUs + segmentBase.availabilityTimeOffsetUs;
-      // getSegmentNum(availabilityEndTimeUs) will not be completed yet.
-      long firstIncompleteSegmentNum = getSegmentNum(availabilityEndTimeUs, periodDurationUs);
-      long firstAvailableSegmentNum = getFirstAvailableSegmentNum(periodDurationUs, nowUnixTimeUs);
-      return (int) (firstIncompleteSegmentNum - firstAvailableSegmentNum);
    }
    @Override

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SegmentBase.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SegmentBase.java
@@ -15,9 +15,12 @@
 */
 package com.google.android.exoplayer2.source.dash.manifest;
+import static com.google.android.exoplayer2.source.dash.DashSegmentIndex.INDEX_UNBOUNDED;
+import static java.lang.Math.max;
 import static java.lang.Math.min;
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.source.dash.DashSegmentIndex;
 import com.google.android.exoplayer2.util.Util;
@@ -119,6 +122,8 @@ public abstract class SegmentBase {
    /* package */ final long startNumber;
    /* package */ final long duration;
    @Nullable /* package */ final List<SegmentTimelineElement> segmentTimeline;
+    private final long timeShiftBufferDepthUs;
+    private final long periodStartUnixTimeUs;
    /**
     * Offset to the current realtime at which segments become available, in microseconds, or {@link
@@ -127,7 +132,7 @@ public abstract class SegmentBase {
     * <p>Segments will be available once their end time &le; currentRealTime +
     * availabilityTimeOffset.
     */
-    /* package */ final long availabilityTimeOffsetUs;
+    @VisibleForTesting /* package */ final long availabilityTimeOffsetUs;
    /**
     * @param initialization A {@link RangedUri} corresponding to initialization data, if such data
@@ -144,6 +149,9 @@ public abstract class SegmentBase {
     *     parameter.
     * @param availabilityTimeOffsetUs The offset to the current realtime at which segments become
     *     available in microseconds, or {@link C#TIME_UNSET} if not applicable.
+     * @param timeShiftBufferDepthUs The time shift buffer depth in microseconds.
+     * @param periodStartUnixTimeUs The start of the enclosing period in microseconds since the Unix
+     *     epoch.
     */
    public MultiSegmentBase(
        @Nullable RangedUri initialization,
@@ -152,15 +160,19 @@ public abstract class SegmentBase {
        long startNumber,
        long duration,
        @Nullable List<SegmentTimelineElement> segmentTimeline,
-        long availabilityTimeOffsetUs) {
+        long availabilityTimeOffsetUs,
+        long timeShiftBufferDepthUs,
+        long periodStartUnixTimeUs) {
      super(initialization, timescale, presentationTimeOffset);
      this.startNumber = startNumber;
      this.duration = duration;
      this.segmentTimeline = segmentTimeline;
      this.availabilityTimeOffsetUs = availabilityTimeOffsetUs;
+      this.timeShiftBufferDepthUs = timeShiftBufferDepthUs;
+      this.periodStartUnixTimeUs = periodStartUnixTimeUs;
    }
-    /** @see DashSegmentIndex#getSegmentNum(long, long) */
+    /** See {@link DashSegmentIndex#getSegmentNum(long, long)}. */
    public long getSegmentNum(long timeUs, long periodDurationUs) {
      final long firstSegmentNum = getFirstSegmentNum();
      final long segmentCount = getSegmentCount(periodDurationUs);
@@ -174,7 +186,7 @@ public abstract class SegmentBase {
        // Ensure we stay within bounds.
        return segmentNum < firstSegmentNum
            ? firstSegmentNum
-            : segmentCount == DashSegmentIndex.INDEX_UNBOUNDED
+            : segmentCount == INDEX_UNBOUNDED
                ? segmentNum
                : min(segmentNum, firstSegmentNum + segmentCount - 1);
      } else {
@@ -196,21 +208,21 @@ public abstract class SegmentBase {
      }
    }
-    /** @see DashSegmentIndex#getDurationUs(long, long) */
+    /** See {@link DashSegmentIndex#getDurationUs(long, long)}. */
    public final long getSegmentDurationUs(long sequenceNumber, long periodDurationUs) {
      if (segmentTimeline != null) {
        long duration = segmentTimeline.get((int) (sequenceNumber - startNumber)).duration;
        return (duration * C.MICROS_PER_SECOND) / timescale;
      } else {
        int segmentCount = getSegmentCount(periodDurationUs);
-        return segmentCount != DashSegmentIndex.INDEX_UNBOUNDED
+        return segmentCount != INDEX_UNBOUNDED
-            && sequenceNumber == (getFirstSegmentNum() + segmentCount - 1)
+                && sequenceNumber == (getFirstSegmentNum() + segmentCount - 1)
            ? (periodDurationUs - getSegmentTimeUs(sequenceNumber))
            : ((duration * C.MICROS_PER_SECOND) / timescale);
      }
    }
-    /** @see DashSegmentIndex#getTimeUs(long) */
+    /** See {@link DashSegmentIndex#getTimeUs(long)}. */
    public final long getSegmentTimeUs(long sequenceNumber) {
      long unscaledSegmentTime;
      if (segmentTimeline != null) {
@@ -227,27 +239,66 @@ public abstract class SegmentBase {
     * Returns a {@link RangedUri} defining the location of a segment for the given index in the
     * given representation.
     *
-     * @see DashSegmentIndex#getSegmentUrl(long)
+     * <p>See {@link DashSegmentIndex#getSegmentUrl(long)}.
     */
    public abstract RangedUri getSegmentUrl(Representation representation, long index);
-    /** @see DashSegmentIndex#getFirstSegmentNum() */
+    /** See {@link DashSegmentIndex#getFirstSegmentNum()}. */
    public long getFirstSegmentNum() {
      return startNumber;
    }
-    /**
+    /** See {@link DashSegmentIndex#getFirstAvailableSegmentNum(long, long)}. */
-     * @see DashSegmentIndex#getSegmentCount(long)
+    public long getFirstAvailableSegmentNum(long periodDurationUs, long nowUnixTimeUs) {
-     */
+      long segmentCount = getSegmentCount(periodDurationUs);
-    public abstract int getSegmentCount(long periodDurationUs);
+      if (segmentCount != INDEX_UNBOUNDED || timeShiftBufferDepthUs == C.TIME_UNSET) {
+        return getFirstSegmentNum();
+      }
+      // The index is itself unbounded. We need to use the current time to calculate the range of
+      // available segments.
+      long liveEdgeTimeInPeriodUs = nowUnixTimeUs - periodStartUnixTimeUs;
+      long timeShiftBufferStartInPeriodUs = liveEdgeTimeInPeriodUs - timeShiftBufferDepthUs;
+      long timeShiftBufferStartSegmentNum =
+          getSegmentNum(timeShiftBufferStartInPeriodUs, periodDurationUs);
+      return max(getFirstSegmentNum(), timeShiftBufferStartSegmentNum);
+    }
-    /**
+    /** See {@link DashSegmentIndex#getAvailableSegmentCount(long, long)}. */
-     * @see DashSegmentIndex#isExplicit()
+    public int getAvailableSegmentCount(long periodDurationUs, long nowUnixTimeUs) {
-     */
+      int segmentCount = getSegmentCount(periodDurationUs);
+      if (segmentCount != INDEX_UNBOUNDED) {
+        return segmentCount;
+      }
+      // The index is itself unbounded. We need to use the current time to calculate the range of
+      // available segments.
+      long liveEdgeTimeInPeriodUs = nowUnixTimeUs - periodStartUnixTimeUs;
+      long availabilityTimeOffsetUs = liveEdgeTimeInPeriodUs + this.availabilityTimeOffsetUs;
+      // getSegmentNum(availabilityTimeOffsetUs) will not be completed yet.
+      long firstIncompleteSegmentNum = getSegmentNum(availabilityTimeOffsetUs, periodDurationUs);
+      long firstAvailableSegmentNum = getFirstAvailableSegmentNum(periodDurationUs, nowUnixTimeUs);
+      return (int) (firstIncompleteSegmentNum - firstAvailableSegmentNum);
+    }
+    /** See {@link DashSegmentIndex#getNextSegmentAvailableTimeUs(long, long)}. */
+    public long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs) {
+      if (segmentTimeline != null) {
+        return C.TIME_UNSET;
+      }
+      long firstIncompleteSegmentNum =
+          getFirstAvailableSegmentNum(periodDurationUs, nowUnixTimeUs)
+              + getAvailableSegmentCount(periodDurationUs, nowUnixTimeUs);
+      return getSegmentTimeUs(firstIncompleteSegmentNum)
+          + getSegmentDurationUs(firstIncompleteSegmentNum, periodDurationUs)
+          - availabilityTimeOffsetUs;
+    }
+    /** See {@link DashSegmentIndex#isExplicit()} */
    public boolean isExplicit() {
      return segmentTimeline != null;
    }
+    /** See {@link DashSegmentIndex#getSegmentCount(long)}. */
+    public abstract int getSegmentCount(long periodDurationUs);
  }
  /** A {@link MultiSegmentBase} that uses a SegmentList to define its segments. */
@@ -271,6 +322,9 @@ public abstract class SegmentBase {
     * @param availabilityTimeOffsetUs The offset to the current realtime at which segments become
     *     available in microseconds, or {@link C#TIME_UNSET} if not applicable.
     * @param mediaSegments A list of {@link RangedUri}s indicating the locations of the segments.
+     * @param timeShiftBufferDepthUs The time shift buffer depth in microseconds.
+     * @param periodStartUnixTimeUs The start of the enclosing period in microseconds since the Unix
+     *     epoch.
     */
    public SegmentList(
        RangedUri initialization,
@@ -280,7 +334,9 @@ public abstract class SegmentBase {
        long duration,
        @Nullable List<SegmentTimelineElement> segmentTimeline,
        long availabilityTimeOffsetUs,
-        @Nullable List<RangedUri> mediaSegments) {
+        @Nullable List<RangedUri> mediaSegments,
+        long timeShiftBufferDepthUs,
+        long periodStartUnixTimeUs) {
      super(
          initialization,
          timescale,
@@ -288,7 +344,9 @@ public abstract class SegmentBase {
          startNumber,
          duration,
          segmentTimeline,
-          availabilityTimeOffsetUs);
+          availabilityTimeOffsetUs,
+          timeShiftBufferDepthUs,
+          periodStartUnixTimeUs);
      this.mediaSegments = mediaSegments;
    }
@@ -339,6 +397,9 @@ public abstract class SegmentBase {
     *     such data exists. If non-null then the {@code initialization} parameter is ignored. If
     *     null then {@code initialization} will be used.
     * @param mediaTemplate A template defining the location of each media segment.
+     * @param timeShiftBufferDepthUs The time shift buffer depth in microseconds.
+     * @param periodStartUnixTimeUs The start of the enclosing period in microseconds since the Unix
+     *     epoch.
     */
    public SegmentTemplate(
        RangedUri initialization,
@@ -350,7 +411,9 @@ public abstract class SegmentBase {
        @Nullable List<SegmentTimelineElement> segmentTimeline,
        long availabilityTimeOffsetUs,
        @Nullable UrlTemplate initializationTemplate,
-        @Nullable UrlTemplate mediaTemplate) {
+        @Nullable UrlTemplate mediaTemplate,
+        long timeShiftBufferDepthUs,
+        long periodStartUnixTimeUs) {
      super(
          initialization,
          timescale,
@@ -358,7 +421,9 @@ public abstract class SegmentBase {
          startNumber,
          duration,
          segmentTimeline,
-          availabilityTimeOffsetUs);
+          availabilityTimeOffsetUs,
+          timeShiftBufferDepthUs,
+          periodStartUnixTimeUs);
      this.initializationTemplate = initializationTemplate;
      this.mediaTemplate = mediaTemplate;
      this.endNumber = endNumber;
@@ -399,7 +464,7 @@ public abstract class SegmentBase {
        long durationUs = (duration * C.MICROS_PER_SECOND) / timescale;
        return (int) Util.ceilDivide(periodDurationUs, durationUs);
      } else {
-        return DashSegmentIndex.INDEX_UNBOUNDED;
+        return INDEX_UNBOUNDED;
      }
    }
  }

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SingleSegmentIndex.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/manifest/SingleSegmentIndex.java
@@ -15,6 +15,7 @@
 */
 package com.google.android.exoplayer2.source.dash.manifest;
+import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.source.dash.DashSegmentIndex;
 /**
@@ -72,6 +73,11 @@ import com.google.android.exoplayer2.source.dash.DashSegmentIndex;
  }
  @Override
+  public long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs) {
+    return C.TIME_UNSET;
+  }
+  @Override
  public boolean isExplicit() {
    return true;
  }

--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/manifest/RepresentationTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/manifest/RepresentationTest.java
@@ -19,16 +19,15 @@ import static com.google.common.truth.Truth.assertThat;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.Format;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-/** Unit test for {@link Representation}. */
+/** Unit test for {@link SegmentBase}. */
 @RunWith(AndroidJUnit4.class)
-public final class RepresentationTest {
+public final class SegmentBaseTest {
  @Test
-  public void getFirstAvailableSegmentNum_multiSegmentRepresentationWithUnboundedTemplate() {
+  public void getFirstAvailableSegmentNum_unboundedSegmentTemplate() {
    long periodStartUnixTimeUs = 123_000_000_000_000L;
    SegmentBase.SegmentTemplate segmentTemplate =
        new SegmentBase.SegmentTemplate(
@@ -41,50 +40,43 @@ public final class RepresentationTest {
            /* segmentTimeline= */ null,
            /* availabilityTimeOffsetUs= */ 500_000,
            /* initializationTemplate= */ null,
-            /* mediaTemplate= */ null);
+            /* mediaTemplate= */ null,
-    Representation.MultiSegmentRepresentation representation =
+            /* timeShiftBufferDepthUs= */ 6_000_000,
-        new Representation.MultiSegmentRepresentation(
+            /* periodStartUnixTimeUs= */ periodStartUnixTimeUs);
-            /* revisionId= */ 0,
-            new Format.Builder().build(),
-            /* baseUrl= */ "https://baseUrl/",
-            segmentTemplate,
-            /* inbandEventStreams= */ null,
-            /* periodStartUnixTimeMs= */ C.usToMs(periodStartUnixTimeUs),
-            /* timeShiftBufferDepthMs= */ 6_000);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs - 10_000_000))
        .isEqualTo(42);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET, /* nowUnixTimeUs= */ periodStartUnixTimeUs))
        .isEqualTo(42);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 7_999_999))
        .isEqualTo(42);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 8_000_000))
        .isEqualTo(43);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 9_999_999))
        .isEqualTo(43);
    assertThat(
-            representation.getFirstAvailableSegmentNum(
+            segmentTemplate.getFirstAvailableSegmentNum(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 10_000_000))
        .isEqualTo(44);
  }
  @Test
-  public void getAvailableSegmentCount_multiSegmentRepresentationWithUnboundedTemplate() {
+  public void getAvailableSegmentCount_unboundedSegmentTemplate() {
    long periodStartUnixTimeUs = 123_000_000_000_000L;
    SegmentBase.SegmentTemplate segmentTemplate =
        new SegmentBase.SegmentTemplate(
@@ -97,55 +89,97 @@ public final class RepresentationTest {
            /* segmentTimeline= */ null,
            /* availabilityTimeOffsetUs= */ 500_000,
            /* initializationTemplate= */ null,
-            /* mediaTemplate= */ null);
+            /* mediaTemplate= */ null,
-    Representation.MultiSegmentRepresentation representation =
+            /* timeShiftBufferDepthUs= */ 6_000_000,
-        new Representation.MultiSegmentRepresentation(
+            /* periodStartUnixTimeUs= */ periodStartUnixTimeUs);
-            /* revisionId= */ 0,
-            new Format.Builder().build(),
-            /* baseUrl= */ "https://baseUrl/",
-            segmentTemplate,
-            /* inbandEventStreams= */ null,
-            /* periodStartUnixTimeMs= */ C.usToMs(periodStartUnixTimeUs),
-            /* timeShiftBufferDepthMs= */ 6_000);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs - 10_000_000))
        .isEqualTo(0);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET, /* nowUnixTimeUs= */ periodStartUnixTimeUs))
        .isEqualTo(0);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 1_499_999))
        .isEqualTo(0);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 1_500_000))
        .isEqualTo(1);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 7_499_999))
        .isEqualTo(3);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 7_500_000))
        .isEqualTo(4);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 7_999_999))
        .isEqualTo(4);
    assertThat(
-            representation.getAvailableSegmentCount(
+            segmentTemplate.getAvailableSegmentCount(
                /* periodDurationUs= */ C.TIME_UNSET,
                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 8_000_000))
        .isEqualTo(3);
  }
+  @Test
+  public void getNextSegmentShiftTimeUse_unboundedSegmentTemplate() {
+    long periodStartUnixTimeUs = 123_000_000_000_000L;
+    SegmentBase.SegmentTemplate segmentTemplate =
+        new SegmentBase.SegmentTemplate(
+            /* initialization= */ null,
+            /* timescale= */ 1000,
+            /* presentationTimeOffset= */ 0,
+            /* startNumber= */ 42,
+            /* endNumber= */ C.INDEX_UNSET,
+            /* duration= */ 2000,
+            /* segmentTimeline= */ null,
+            /* availabilityTimeOffsetUs= */ 500_000,
+            /* initializationTemplate= */ null,
+            /* mediaTemplate= */ null,
+            /* timeShiftBufferDepthUs= */ 6_000_000,
+            /* periodStartUnixTimeUs= */ periodStartUnixTimeUs);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET,
+                /* nowUnixTimeUs= */ periodStartUnixTimeUs - 10_000_000))
+        .isEqualTo(1_500_000);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET, /* nowUnixTimeUs= */ periodStartUnixTimeUs))
+        .isEqualTo(1_500_000);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET,
+                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 1_499_999))
+        .isEqualTo(1_500_000);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET,
+                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 1_500_000))
+        .isEqualTo(3_500_000);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET,
+                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 17_499_999))
+        .isEqualTo(17_500_000);
+    assertThat(
+            segmentTemplate.getNextSegmentAvailableTimeUs(
+                /* periodDurationUs= */ C.TIME_UNSET,
+                /* nowUnixTimeUs= */ periodStartUnixTimeUs + 17_500_000))
+        .isEqualTo(19_500_000);
+  }
 }