1 files changed, 74 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/wav/WavSeekMap.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/wav/WavSeekMap.java
new file mode 100644
index 0000000000..d14268d120
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/wav/WavSeekMap.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.wav;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.C;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.SeekMap;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.SeekPoint;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+
+/* package */ final class WavSeekMap implements SeekMap {
+
+  private final WavHeader wavHeader;
+  private final int framesPerBlock;
+  private final long firstBlockPosition;
+  private final long blockCount;
+  private final long durationUs;
+
+  public WavSeekMap(
+      WavHeader wavHeader, int framesPerBlock, long dataStartPosition, long dataEndPosition) {
+    this.wavHeader = wavHeader;
+    this.framesPerBlock = framesPerBlock;
+    this.firstBlockPosition = dataStartPosition;
+    this.blockCount = (dataEndPosition - dataStartPosition) / wavHeader.blockSize;
+    durationUs = blockIndexToTimeUs(blockCount);
+  }
+
+  @Override
+  public boolean isSeekable() {
+    return true;
+  }
+
+  @Override
+  public long getDurationUs() {
+    return durationUs;
+  }
+
+  @Override
+  public SeekPoints getSeekPoints(long timeUs) {
+    // Calculate the containing block index, constraining to valid indices.
+    long blockIndex = (timeUs * wavHeader.frameRateHz) / (C.MICROS_PER_SECOND * framesPerBlock);
+    blockIndex = Util.constrainValue(blockIndex, 0, blockCount - 1);
+
+    long seekPosition = firstBlockPosition + (blockIndex * wavHeader.blockSize);
+    long seekTimeUs = blockIndexToTimeUs(blockIndex);
+    SeekPoint seekPoint = new SeekPoint(seekTimeUs, seekPosition);
+    if (seekTimeUs >= timeUs || blockIndex == blockCount - 1) {
+      return new SeekPoints(seekPoint);
+    } else {
+      long secondBlockIndex = blockIndex + 1;
+      long secondSeekPosition = firstBlockPosition + (secondBlockIndex * wavHeader.blockSize);
+      long secondSeekTimeUs = blockIndexToTimeUs(secondBlockIndex);
+      SeekPoint secondSeekPoint = new SeekPoint(secondSeekTimeUs, secondSeekPosition);
+      return new SeekPoints(seekPoint, secondSeekPoint);
+    }
+  }
+
+  private long blockIndexToTimeUs(long blockIndex) {
+    return Util.scaleLargeTimestamp(
+        blockIndex * framesPerBlock, C.MICROS_PER_SECOND, wavHeader.frameRateHz);
+  }
+}