Correctly use "current-manifest-live" v.s. "stream-is-live"

When a live stream ends, what typically happens is that the manifest
is refreshed and the refreshed version is not marked as live/dynamic.
When this happens we:

1. Don't want the duration of the track to change.
2. Still want to consider the possibility that we may have fallen behind
   the live window.
3. Don't want to allow futher manifest refreshes.

This change uses the right thing in the right place.

library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java

@@ -119,6 +119,7 @@ public NoAdaptationSetException(String message) {
   private final long liveEdgeLatencyUs;
   private final long elapsedRealtimeOffsetUs;
   private final long[] availableRangeValues;
+  private final boolean live;
 
   private MediaPresentationDescription currentManifest;
   private ExposedTrack enabledTrack;
@@ -260,7 +261,8 @@ dataSource, adaptiveFormatEvaluator, new SystemClock(), liveEdgeLatencyMs * 1000
     this.evaluation = new Evaluation();
     this.availableRangeValues = new long[2];
     periodHolders = new SparseArray<>();
-    tracks = new ArrayList<ExposedTrack>();
+    tracks = new ArrayList<>();
+    live = initialManifest.dynamic;
   }
 
   // ChunkSource implementation.
@@ -375,7 +377,7 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
 
     availableRange.getCurrentBoundsUs(availableRangeValues);
     if (queue.isEmpty()) {
-      if (currentManifest.dynamic) {
+      if (live) {
         if (startAtLiveEdge) {
           // We want live streams to start at the live edge instead of the beginning of the
           // manifest
@@ -403,18 +405,16 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
         return;
       }
 
-      if (currentManifest.dynamic) {
-        long nextSegmentStartTimeUs = previous.endTimeUs;
-        if (nextSegmentStartTimeUs < availableRangeValues[0]) {
-          // This is before the first chunk in the current manifest.
-          fatalError = new BehindLiveWindowException();
-          return;
-        } else if (nextSegmentStartTimeUs >= availableRangeValues[1]) {
-          // This chunk is beyond the last chunk in the current manifest. If the index is bounded
-          // we'll need to wait until it's refreshed. If it's unbounded we just need to wait for a
-          // while before attempting to load the chunk.
-          return;
-        }
+      long nextSegmentStartTimeUs = previous.endTimeUs;
+      if (live && nextSegmentStartTimeUs < availableRangeValues[0]) {
+        // This is before the first chunk in the current manifest.
+        fatalError = new BehindLiveWindowException();
+        return;
+      } else if (currentManifest.dynamic && nextSegmentStartTimeUs >= availableRangeValues[1]) {
+        // This chunk is beyond the last chunk in the current manifest. If the index is bounded
+        // we'll need to wait until it's refreshed. If it's unbounded we just need to wait for a
+        // while before attempting to load the chunk.
+        return;
       }
 
       startingNewPeriod = false;
@@ -545,7 +545,7 @@ public void adaptiveTrack(MediaPresentationDescription manifest, int periodIndex
       representationFormats[i] = format;
     }
     Arrays.sort(representationFormats, new DecreasingBandwidthComparator());
-    long trackDurationUs = manifest.dynamic ? C.UNKNOWN_TIME_US : manifest.duration * 1000;
+    long trackDurationUs = live ? C.UNKNOWN_TIME_US : manifest.duration * 1000;
     String mediaMimeType = getMediaMimeType(maxHeightRepresentationFormat);
     if (mediaMimeType == null) {
       Log.w(TAG, "Skipped adaptive track (unknown media mime type)");

library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java

@@ -221,7 +221,7 @@ public HlsChunkSource(DataSource dataSource, String playlistUrl, HlsPlaylist pla
   }
 
   public long getDurationUs() {
-    return live ? C.UNKNOWN_TIME_US : durationUs;
+    return durationUs;
   }
 
   /**
@@ -551,7 +551,7 @@ private void setMediaPlaylist(int variantIndex, HlsMediaPlaylist mediaPlaylist)
     variantLastPlaylistLoadTimesMs[variantIndex] = SystemClock.elapsedRealtime();
     variantPlaylists[variantIndex] = mediaPlaylist;
     live |= mediaPlaylist.live;
-    durationUs = mediaPlaylist.durationUs;
+    durationUs = live ? C.UNKNOWN_TIME_US : mediaPlaylist.durationUs;
   }
 
   /**

library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer.smoothstreaming;
 
 import com.google.android.exoplayer.BehindLiveWindowException;
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.MediaFormat;
 import com.google.android.exoplayer.chunk.Chunk;
 import com.google.android.exoplayer.chunk.ChunkExtractorWrapper;
@@ -69,6 +70,7 @@ public class SmoothStreamingChunkSource implements ChunkSource,
   private final ManifestFetcher<SmoothStreamingManifest> manifestFetcher;
   private final DrmInitData.Mapped drmInitData;
   private final FormatEvaluator adaptiveFormatEvaluator;
+  private final boolean live;
 
   // The tracks exposed by this source.
   private final ArrayList<ExposedTrack> tracks;
@@ -80,7 +82,7 @@ public class SmoothStreamingChunkSource implements ChunkSource,
   private boolean prepareCalled;
   private SmoothStreamingManifest currentManifest;
   private int currentManifestChunkOffset;
-  private boolean currentManifestFinished;
+  private boolean needManifestRefresh;
   private ExposedTrack enabledTrack;
   private IOException fatalError;
 
@@ -135,6 +137,7 @@ private SmoothStreamingChunkSource(ManifestFetcher<SmoothStreamingManifest> mani
     tracks = new ArrayList<>();
     extractorWrappers = new SparseArray<>();
     mediaFormats = new SparseArray<>();
+    live = initialManifest.isLive;
 
     ProtectionElement protectionElement = initialManifest.protectionElement;
     if (protectionElement != null) {
@@ -221,10 +224,10 @@ public void continueBuffering(long playbackPositionUs) {
         }
       }
       currentManifest = newManifest;
-      currentManifestFinished = false;
+      needManifestRefresh = false;
     }
 
-    if (currentManifestFinished && (SystemClock.elapsedRealtime()
+    if (needManifestRefresh && (SystemClock.elapsedRealtime()
         > manifestFetcher.getManifestLoadStartTimestamp() + MINIMUM_MANIFEST_REFRESH_PERIOD_MS)) {
       manifestFetcher.requestRefresh();
     }
@@ -265,14 +268,15 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
 
     StreamElement streamElement = currentManifest.streamElements[enabledTrack.elementIndex];
     if (streamElement.chunkCount == 0) {
-      // The manifest is currently empty for this stream.
-      currentManifestFinished = true;
+      if (currentManifest.isLive) {
+        needManifestRefresh = true;
+      }
       return;
     }
 
     int chunkIndex;
     if (queue.isEmpty()) {
-      if (currentManifest.isLive) {
+      if (live) {
         seekPositionUs = getLiveSeekPosition(currentManifest, liveEdgeLatencyUs);
       }
       chunkIndex = streamElement.getChunkIndex(seekPositionUs);
@@ -281,19 +285,19 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
       chunkIndex = previous.isLastChunk ? -1 : previous.chunkIndex + 1 - currentManifestChunkOffset;
     }
 
-    if (currentManifest.isLive) {
-      if (chunkIndex < 0) {
-        // This is before the first chunk in the current manifest.
-        fatalError = new BehindLiveWindowException();
-        return;
-      } else if (chunkIndex >= streamElement.chunkCount) {
+    if (live && chunkIndex < 0) {
+      // This is before the first chunk in the current manifest.
+      fatalError = new BehindLiveWindowException();
+      return;
+    } else if (currentManifest.isLive) {
+      if (chunkIndex >= streamElement.chunkCount) {
         // This is beyond the last chunk in the current manifest.
-        currentManifestFinished = true;
+        needManifestRefresh = true;
         return;
       } else if (chunkIndex == streamElement.chunkCount - 1) {
         // This is the last chunk in the current manifest. Mark the manifest as being finished,
         // but continue to return the final chunk.
-        currentManifestFinished = true;
+        needManifestRefresh = true;
       }
     }
 
@@ -388,7 +392,7 @@ private MediaFormat initManifestTrack(SmoothStreamingManifest manifest, int elem
     }
 
     // Build the media format.
-    long durationUs = manifest.durationUs;
+    long durationUs = live ? C.UNKNOWN_TIME_US : manifest.durationUs;
     StreamElement element = manifest.streamElements[elementIndex];
     Format format = element.tracks[trackIndex].format;
     byte[][] csdArray = element.tracks[trackIndex].csd;