Add utility methods for inexact ceil/floor binary searches.

This change also fixes issue #5

library/src/main/java/com/google/android/exoplayer/dash/DashMp4ChunkSource.java

@@ -33,6 +33,7 @@
 import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.upstream.DataSpec;
 import com.google.android.exoplayer.upstream.NonBlockingInputStream;
+import com.google.android.exoplayer.util.Util;
 
 import android.util.Log;
 
@@ -170,8 +171,8 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
 
     int nextIndex;
     if (queue.isEmpty()) {
-      nextIndex = Arrays.binarySearch(extractor.getSegmentIndex().timesUs, seekPositionUs);
-      nextIndex = nextIndex < 0 ? -nextIndex - 2 : nextIndex;
+      nextIndex = Util.binarySearchFloor(extractor.getSegmentIndex().timesUs, seekPositionUs,
+          true, true);
     } else {
       nextIndex = queue.get(out.queueSize - 1).nextChunkIndex;
     }
@@ -196,7 +197,7 @@ public IOException getError() {
   public void onChunkLoadError(Chunk chunk, Exception e) {
     // Do nothing.
   }
-  
+
   private static Chunk newInitializationChunk(Representation representation,
       FragmentedMp4Extractor extractor, DataSource dataSource, int trigger) {
     DataSpec dataSpec = new DataSpec(representation.uri, 0, representation.indexEnd + 1,

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

@@ -33,6 +33,7 @@
 import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.upstream.DataSpec;
 import com.google.android.exoplayer.upstream.NonBlockingInputStream;
+import com.google.android.exoplayer.util.Util;
 
 import android.util.Log;
 
@@ -151,8 +152,7 @@ public final void getChunkOperation(List<? extends MediaChunk> queue, long seekP
 
     int nextIndex;
     if (queue.isEmpty()) {
-      nextIndex = Arrays.binarySearch(extractor.getCues().timesUs, seekPositionUs);
-      nextIndex = nextIndex < 0 ? -nextIndex - 2 : nextIndex;
+      nextIndex = Util.binarySearchFloor(extractor.getCues().timesUs, seekPositionUs, true, true);
     } else {
       nextIndex = queue.get(out.queueSize - 1).nextChunkIndex;
     }

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

@@ -16,8 +16,8 @@
 package com.google.android.exoplayer.smoothstreaming;
 
 import com.google.android.exoplayer.util.MimeTypes;
+import com.google.android.exoplayer.util.Util;
 
-import java.util.Arrays;
 import java.util.UUID;
 
 /**
@@ -195,9 +195,7 @@ public StreamElement(int type, String subType, long timeScale, String name,
      * @return The index of the corresponding chunk.
      */
     public int getChunkIndex(long timeUs) {
-      long time = (timeUs * timeScale) / 1000000L;
-      int chunkIndex = Arrays.binarySearch(chunkStartTimes, time);
-      return chunkIndex < 0 ? -chunkIndex - 2 : chunkIndex;
+      return Util.binarySearchFloor(chunkStartTimes, (timeUs * timeScale) / 1000000L, true, true);
     }
 
     /**

library/src/main/java/com/google/android/exoplayer/text/ttml/TtmlSubtitle.java

@@ -16,8 +16,7 @@
 package com.google.android.exoplayer.text.ttml;
 
 import com.google.android.exoplayer.text.Subtitle;
-
-import java.util.Arrays;
+import com.google.android.exoplayer.util.Util;
 
 /**
  * A representation of a TTML subtitle.
@@ -41,8 +40,7 @@ public long getStartTime() {
 
   @Override
   public int getNextEventTimeIndex(long timeUs) {
-    int index = Arrays.binarySearch(eventTimesUs, timeUs - startTimeUs);
-    index = index >= 0 ? index + 1 : ~index;
+    int index = Util.binarySearchCeil(eventTimesUs, timeUs - startTimeUs, false, false);
     return index < eventTimesUs.length ? index : -1;
   }
 

library/src/main/java/com/google/android/exoplayer/util/Util.java

@@ -19,6 +19,9 @@
 
 import java.io.IOException;
 import java.net.URL;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -112,4 +115,88 @@ public static String toLowerInvariant(String text) {
     return text == null ? null : text.toLowerCase(Locale.US);
   }
 
+  /**
+   * Returns the index of the largest value in an array that is less than (or optionally equal to)
+   * a specified key.
+   * <p>
+   * The search is performed using a binary search algorithm, and so the array must be sorted.
+   *
+   * @param a The array to search.
+   * @param key The key being searched for.
+   * @param inclusive If the key is present in the array, whether to return the corresponding index.
+   *     If false then the returned index corresponds to the largest value in the array that is
+   *     strictly less than the key.
+   * @param stayInBounds If true, then 0 will be returned in the case that the key is smaller than
+   *     the smallest value in the array. If false then -1 will be returned.
+   */
+  public static int binarySearchFloor(long[] a, long key, boolean inclusive, boolean stayInBounds) {
+    int index = Arrays.binarySearch(a, key);
+    index = index < 0 ? -(index + 2) : (inclusive ? index : (index - 1));
+    return stayInBounds ? Math.max(0, index) : index;
+  }
+
+  /**
+   * Returns the index of the smallest value in an array that is greater than (or optionally equal
+   * to) a specified key.
+   * <p>
+   * The search is performed using a binary search algorithm, and so the array must be sorted.
+   *
+   * @param a The array to search.
+   * @param key The key being searched for.
+   * @param inclusive If the key is present in the array, whether to return the corresponding index.
+   *     If false then the returned index corresponds to the smallest value in the array that is
+   *     strictly greater than the key.
+   * @param stayInBounds If true, then {@code (a.length - 1)} will be returned in the case that the
+   *     key is greater than the largest value in the array. If false then {@code a.length} will be
+   *     returned.
+   */
+  public static int binarySearchCeil(long[] a, long key, boolean inclusive, boolean stayInBounds) {
+    int index = Arrays.binarySearch(a, key);
+    index = index < 0 ? ~index : (inclusive ? index : (index + 1));
+    return stayInBounds ? Math.min(a.length - 1, index) : index;
+  }
+
+  /**
+   * Returns the index of the largest value in an list that is less than (or optionally equal to)
+   * a specified key.
+   * <p>
+   * The search is performed using a binary search algorithm, and so the list must be sorted.
+   *
+   * @param list The list to search.
+   * @param key The key being searched for.
+   * @param inclusive If the key is present in the list, whether to return the corresponding index.
+   *     If false then the returned index corresponds to the largest value in the list that is
+   *     strictly less than the key.
+   * @param stayInBounds If true, then 0 will be returned in the case that the key is smaller than
+   *     the smallest value in the list. If false then -1 will be returned.
+   */
+  public static<T> int binarySearchFloor(List<? extends Comparable<? super T>> list, T key,
+      boolean inclusive, boolean stayInBounds) {
+    int index = Collections.binarySearch(list, key);
+    index = index < 0 ? -(index + 2) : (inclusive ? index : (index - 1));
+    return stayInBounds ? Math.max(0, index) : index;
+  }
+
+  /**
+   * Returns the index of the smallest value in an list that is greater than (or optionally equal
+   * to) a specified key.
+   * <p>
+   * The search is performed using a binary search algorithm, and so the list must be sorted.
+   *
+   * @param list The list to search.
+   * @param key The key being searched for.
+   * @param inclusive If the key is present in the list, whether to return the corresponding index.
+   *     If false then the returned index corresponds to the smallest value in the list that is
+   *     strictly greater than the key.
+   * @param stayInBounds If true, then {@code (list.size() - 1)} will be returned in the case that
+   *     the key is greater than the largest value in the list. If false then {@code list.size()}
+   *     will be returned.
+   */
+  public static<T> int binarySearchCeil(List<? extends Comparable<? super T>> list, T key,
+      boolean inclusive, boolean stayInBounds) {
+    int index = Collections.binarySearch(list, key);
+    index = index < 0 ? ~index : (inclusive ? index : (index + 1));
+    return stayInBounds ? Math.min(list.size() - 1, index) : index;
+  }
+
 }