'improve_far_seek_of_chunkSampleStream'

library/src/main/java/com/google/android/exoplayer2/extractor/DefaultTrackOutput.java

@@ -225,6 +225,22 @@ public final class DefaultTrackOutput implements TrackOutput {
     return infoQueue.getLargestQueuedTimestampUs();
   }
 
+  /**
+   * Attempts to skip to the keyframe before the specified time, if it's present in the buffer.
+   *
+   * @param timeUs The seek time.
+   * @param skipToLastKey Skip to last key regardless the seek time is out of range .
+   * @return Whether the skip was successful.
+   */
+  public boolean skipToKeyframeBefore(long timeUs, boolean skipToLastKey) {
+    long nextOffset = infoQueue.skipToKeyframeBefore(timeUs, skipToLastKey);
+    if (nextOffset == C.POSITION_UNSET) {
+      return false;
+    }
+    dropDownstreamTo(nextOffset);
+    return true;
+  }
+
   /**
    * Attempts to skip to the keyframe before the specified time, if it's present in the buffer.
    *
@@ -232,7 +248,7 @@ public final class DefaultTrackOutput implements TrackOutput {
    * @return Whether the skip was successful.
    */
   public boolean skipToKeyframeBefore(long timeUs) {
-    long nextOffset = infoQueue.skipToKeyframeBefore(timeUs);
+    long nextOffset = infoQueue.skipToKeyframeBefore(timeUs, false);
     if (nextOffset == C.POSITION_UNSET) {
       return false;
     }
@@ -781,12 +797,12 @@ public final class DefaultTrackOutput implements TrackOutput {
      * @return The offset of the keyframe's data if the keyframe was present.
      *     {@link C#POSITION_UNSET} otherwise.
      */
-    public synchronized long skipToKeyframeBefore(long timeUs) {
+    public synchronized long skipToKeyframeBefore(long timeUs, boolean skipToLastKey) {
       if (queueSize == 0 || timeUs < timesUs[relativeReadIndex]) {
         return C.POSITION_UNSET;
       }
 
-      if (timeUs > largestQueuedTimestampUs) {
+      if (timeUs > largestQueuedTimestampUs && !skipToLastKey) {
         return C.POSITION_UNSET;
       }
 

library/src/main/java/com/google/android/exoplayer2/source/chunk/ChunkSampleStream.java

@@ -114,6 +114,20 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
     }
   }
 
+  /**
+   * Check if the input position locates within the chunk we are downloading now.
+   *
+   * @param positionUs The target position in microseconds.
+   * @return Whether the input position locates within the chunk we are downloading now.
+   */
+  public boolean isWithinLastChunk(long positionUs) {
+    if (isPendingReset() || loadingFinished) {
+      return false;
+    } else {
+      return ((positionUs >= getCurrentLoadPositionUs()) && (positionUs < getNextLoadPositionUs()));
+    }
+  }
+
   /**
    * Seeks to the specified position in microseconds.
    *
@@ -122,7 +136,8 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
   public void seekToUs(long positionUs) {
     lastSeekPositionUs = positionUs;
     // If we're not pending a reset, see if we can seek within the sample queue.
-    boolean seekInsideBuffer = !isPendingReset() && sampleQueue.skipToKeyframeBefore(positionUs);
+    boolean seekInsideBuffer = !isPendingReset() && 
+        sampleQueue.skipToKeyframeBefore(positionUs, isWithinLastChunk(positionUs));
     if (seekInsideBuffer) {
       // We succeeded. All we need to do is discard any chunks that we've moved past.
       while (mediaChunks.size() > 1
@@ -284,6 +299,14 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
     return true;
   }
 
+  public long getCurrentLoadPositionUs() {
+    if (isPendingReset()) {
+      return pendingResetPositionUs;
+    } else {
+      return loadingFinished ? C.TIME_END_OF_SOURCE : mediaChunks.getLast().startTimeUs;
+    }
+  }
+
   @Override
   public long getNextLoadPositionUs() {
     if (isPendingReset()) {