Make OggVorbisExtractor seekable.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117252304

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/OggReaderTest.java

@@ -15,8 +15,9 @@
  */
 package com.google.android.exoplayer.extractor.ogg;
 
+import com.google.android.exoplayer.ParserException;
+import com.google.android.exoplayer.extractor.ExtractorInput;
 import com.google.android.exoplayer.testutil.FakeExtractorInput;
-import com.google.android.exoplayer.testutil.FakeExtractorInput.SimulatedIOException;
 import com.google.android.exoplayer.testutil.TestUtil;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
@@ -24,12 +25,13 @@ import android.test.MoreAsserts;
 
 import junit.framework.TestCase;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Random;
 
 /**
- * Unit test for {@link OggReader}
+ * Unit test for {@link OggReader}.
  */
 public final class OggReaderTest extends TestCase {
 
@@ -51,7 +53,7 @@ public final class OggReaderTest extends TestCase {
     byte[] thirdPacket = TestUtil.buildTestData(256, random);
     byte[] fourthPacket = TestUtil.buildTestData(271, random);
 
-    FakeExtractorInput input = createInput(
+    FakeExtractorInput input = TestData.createInput(
         TestUtil.joinByteArrays(
             // First page with a single packet.
             TestData.buildOggHeader(0x02,  0, 1000, 0x01),
@@ -67,7 +69,7 @@ public final class OggReaderTest extends TestCase {
             TestData.buildOggHeader(0x04,  128, 1003, 0x04),
             TestUtil.createByteArray(0xFF, 0x01, 0xFF, 0x10), // Laces
             thirdPacket,
-            fourthPacket));
+            fourthPacket), true);
 
     assertReadPacket(input, firstPacket);
     assertTrue((oggReader.getPageHeader().type & 0x02) == 0x02);
@@ -111,12 +113,12 @@ public final class OggReaderTest extends TestCase {
     byte[] firstPacket = TestUtil.buildTestData(255, random);
     byte[] secondPacket = TestUtil.buildTestData(8, random);
 
-    FakeExtractorInput input = createInput(
+    FakeExtractorInput input = TestData.createInput(
         TestUtil.joinByteArrays(
             TestData.buildOggHeader(0x06, 0, 1000, 0x04),
             TestUtil.createByteArray(0xFF, 0x00, 0x00, 0x08), // Laces.
             firstPacket,
-            secondPacket));
+            secondPacket), true);
 
     assertReadPacket(input, firstPacket);
     assertReadPacket(input, secondPacket);
@@ -126,7 +128,7 @@ public final class OggReaderTest extends TestCase {
   public void testReadContinuedPacketOverTwoPages() throws Exception {
     byte[] firstPacket = TestUtil.buildTestData(518);
 
-    FakeExtractorInput input = createInput(
+    FakeExtractorInput input = TestData.createInput(
         TestUtil.joinByteArrays(
             // First page.
             TestData.buildOggHeader(0x02, 0, 1000, 0x02),
@@ -135,7 +137,7 @@ public final class OggReaderTest extends TestCase {
             // Second page (continued packet).
             TestData.buildOggHeader(0x05, 10, 1001, 0x01),
             TestUtil.createByteArray(0x08), // Laces.
-            Arrays.copyOfRange(firstPacket, 510, 510 + 8)));
+            Arrays.copyOfRange(firstPacket, 510, 510 + 8)), true);
 
     assertReadPacket(input, firstPacket);
     assertTrue((oggReader.getPageHeader().type & 0x04) == 0x04);
@@ -148,7 +150,7 @@ public final class OggReaderTest extends TestCase {
   public void testReadContinuedPacketOverFourPages() throws Exception {
     byte[] firstPacket = TestUtil.buildTestData(1028);
 
-    FakeExtractorInput input = createInput(
+    FakeExtractorInput input = TestData.createInput(
         TestUtil.joinByteArrays(
             // First page.
             TestData.buildOggHeader(0x02, 0, 1000, 0x02),
@@ -165,7 +167,7 @@ public final class OggReaderTest extends TestCase {
             // Fourth page (continued packet).
             TestData.buildOggHeader(0x05, 10, 1003, 0x01),
             TestUtil.createByteArray(0x08), // Laces.
-            Arrays.copyOfRange(firstPacket, 510 + 255 + 255, 510 + 255 + 255 + 8)));
+            Arrays.copyOfRange(firstPacket, 510 + 255 + 255, 510 + 255 + 255 + 8)), true);
 
     assertReadPacket(input, firstPacket);
     assertTrue((oggReader.getPageHeader().type & 0x04) == 0x04);
@@ -175,12 +177,27 @@ public final class OggReaderTest extends TestCase {
     assertReadEof(input);
   }
 
+  public void testReadDiscardContinuedPacketAtStart() throws Exception {
+    byte[] pageBody = TestUtil.buildTestData(256 + 8);
+
+    FakeExtractorInput input = TestData.createInput(
+        TestUtil.joinByteArrays(
+            // Page with a continued packet at start.
+            TestData.buildOggHeader(0x01, 10, 1001, 0x03),
+            TestUtil.createByteArray(255, 1, 8), // Laces.
+            pageBody), true);
+
+    // Expect the first partial packet to be discarded.
+    assertReadPacket(input, Arrays.copyOfRange(pageBody, 256, 256 + 8));
+    assertReadEof(input);
+  }
+
   public void testReadZeroSizedPacketsAtEndOfStream() throws Exception {
     byte[] firstPacket = TestUtil.buildTestData(8, random);
     byte[] secondPacket = TestUtil.buildTestData(8, random);
     byte[] thirdPacket = TestUtil.buildTestData(8, random);
 
-    FakeExtractorInput input = createInput(
+    FakeExtractorInput input = TestData.createInput(
         TestUtil.joinByteArrays(
             TestData.buildOggHeader(0x02, 0, 1000, 0x01),
             TestUtil.createByteArray(0x08), // Laces.
@@ -190,7 +207,7 @@ public final class OggReaderTest extends TestCase {
             secondPacket,
             TestData.buildOggHeader(0x04, 0, 1002, 0x03),
             TestUtil.createByteArray(0x08, 0x00, 0x00), // Laces.
-            thirdPacket));
+            thirdPacket), true);
 
     assertReadPacket(input, firstPacket);
     assertReadPacket(input, secondPacket);
@@ -198,9 +215,127 @@ public final class OggReaderTest extends TestCase {
     assertReadEof(input);
   }
 
-  private static FakeExtractorInput createInput(byte[] data) {
+  public void testSkipToPageOfGranule() throws IOException, InterruptedException {
-    return new FakeExtractorInput.Builder().setData(data).setSimulateIOErrors(true)
+    byte[] packet = TestUtil.buildTestData(3 * 254, random);
-        .setSimulateUnknownLength(true).setSimulatePartialReads(true).build();
+    FakeExtractorInput input = TestData.createInput(
+        TestUtil.joinByteArrays(
+            TestData.buildOggHeader(0x01, 20000, 1000, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 40000, 1001, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 60000, 1002, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet), false);
+
+    // expect to be granule of the previous page returned as elapsedSamples
+    skipToPageOfGranule(input, 54000, 40000);
+    // expect to be at the start of the third page
+    assertEquals(2 * (30 + (3 * 254)), input.getPosition());
+  }
+
+  public void testSkipToPageOfGranulePreciseMatch() throws IOException, InterruptedException {
+    byte[] packet = TestUtil.buildTestData(3 * 254, random);
+    FakeExtractorInput input = TestData.createInput(
+        TestUtil.joinByteArrays(
+            TestData.buildOggHeader(0x01, 20000, 1000, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 40000, 1001, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 60000, 1002, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet), false);
+
+    skipToPageOfGranule(input, 40000, 20000);
+    // expect to be at the start of the second page
+    assertEquals((30 + (3 * 254)), input.getPosition());
+  }
+
+  public void testSkipToPageOfGranuleAfterTargetPage() throws IOException, InterruptedException {
+    byte[] packet = TestUtil.buildTestData(3 * 254, random);
+    FakeExtractorInput input = TestData.createInput(
+        TestUtil.joinByteArrays(
+            TestData.buildOggHeader(0x01, 20000, 1000, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 40000, 1001, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet,
+            TestData.buildOggHeader(0x04, 60000, 1002, 0x03),
+            TestUtil.createByteArray(254, 254, 254), // Laces.
+            packet), false);
+
+    try {
+      skipToPageOfGranule(input, 10000, 20000);
+      fail();
+    } catch (ParserException e) {
+      // ignored
+    }
+    assertEquals(0, input.getPosition());
+  }
+
+  private void skipToPageOfGranule(ExtractorInput input, long granule,
+      long elapsedSamplesExpected) throws IOException, InterruptedException {
+    while (true) {
+      try {
+        assertEquals(elapsedSamplesExpected, oggReader.skipToPageOfGranule(input, granule));
+        return;
+      } catch (FakeExtractorInput.SimulatedIOException e) {
+        input.resetPeekPosition();
+      }
+    }
+  }
+
+  public void testReadGranuleOfLastPage() throws IOException, InterruptedException {
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestUtil.buildTestData(100, random),
+        TestData.buildOggHeader(0x00, 20000, 66, 3),
+        TestUtil.createByteArray(254, 254, 254), // laces
+        TestUtil.buildTestData(3 * 254, random),
+        TestData.buildOggHeader(0x00, 40000, 67, 3),
+        TestUtil.createByteArray(254, 254, 254), // laces
+        TestUtil.buildTestData(3 * 254, random),
+        TestData.buildOggHeader(0x05, 60000, 68, 3),
+        TestUtil.createByteArray(254, 254, 254), // laces
+        TestUtil.buildTestData(3 * 254, random)
+    ), false);
+    assertReadGranuleOfLastPage(input, 60000);
+  }
+
+  public void testReadGranuleOfLastPageAfterLastHeader() throws IOException, InterruptedException {
+    FakeExtractorInput input = TestData.createInput(TestUtil.buildTestData(100, random), false);
+    try {
+      assertReadGranuleOfLastPage(input, 60000);
+      fail();
+    } catch (EOFException e) {
+      // ignored
+    }
+  }
+
+  public void testReadGranuleOfLastPageWithUnboundedLength()
+      throws IOException, InterruptedException {
+    FakeExtractorInput input = TestData.createInput(new byte[0], true);
+    try {
+      assertReadGranuleOfLastPage(input, 60000);
+      fail();
+    } catch (IllegalArgumentException e) {
+      // ignored
+    }
+  }
+
+  private void assertReadGranuleOfLastPage(FakeExtractorInput input, int expected)
+      throws IOException, InterruptedException {
+    while (true) {
+      try {
+        assertEquals(expected, oggReader.readGranuleOfLastPage(input));
+        break;
+      } catch (FakeExtractorInput.SimulatedIOException e) {
+        // ignored
+      }
+    }
   }
 
   private void assertReadPacket(FakeExtractorInput extractorInput, byte[] expected)
@@ -221,7 +356,7 @@ public final class OggReaderTest extends TestCase {
     while (true) {
       try {
         return oggReader.readPacket(input, scratch);
-      } catch (SimulatedIOException e) {
+      } catch (FakeExtractorInput.SimulatedIOException e) {
         // Ignore.
       }
     }

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/OggSeekerTest.java

@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2015 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 com.google.android.exoplayer.extractor.ogg;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.testutil.FakeExtractorInput;
+import com.google.android.exoplayer.testutil.TestUtil;
+
+import junit.framework.TestCase;
+
+import java.io.IOException;
+
+/**
+ * Unit test for {@link OggSeeker}.
+ */
+public final class OggSeekerTest extends TestCase {
+
+  private OggSeeker oggSeeker;
+
+  @Override
+  public void setUp() throws Exception {
+    super.setUp();
+    oggSeeker = new OggSeeker();
+    oggSeeker.setup(1, 1);
+  }
+
+  public void testSetupUnboundAudioLength() {
+    try {
+      new OggSeeker().setup(C.LENGTH_UNBOUNDED, 1000);
+      fail();
+    } catch (IllegalArgumentException e) {
+      // ignored
+    }
+  }
+
+  public void testSetupZeroOrNegativeTotalSamples() {
+    try {
+      new OggSeeker().setup(1000, 0);
+      fail();
+    } catch (IllegalArgumentException e) {
+      // ignored
+    }
+    try {
+      new OggSeeker().setup(1000, -1000);
+      fail();
+    } catch (IllegalArgumentException e) {
+      // ignored
+    }
+  }
+
+  public void testGetNextSeekPositionSetupNotCalled() throws IOException, InterruptedException {
+    try {
+      new OggSeeker().getNextSeekPosition(1000, TestData.createInput(new byte[0], false));
+      fail();
+    } catch (IllegalStateException e) {
+      // ignored
+    }
+  }
+
+  public void testGetNextSeekPositionMatch() throws IOException, InterruptedException {
+    long targetGranule = 100000;
+    long headerGranule = 52001;
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x00, headerGranule, 22, 2),
+        TestUtil.createByteArray(54, 55) // laces
+    ), false);
+    long expectedPosition = -1;
+    assertGetNextSeekPosition(expectedPosition, targetGranule, input);
+  }
+
+  public void testGetNextSeekPositionTooHigh() throws IOException, InterruptedException {
+    long targetGranule = 100000;
+    long headerGranule = 200000;
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x00, headerGranule, 22, 2),
+        TestUtil.createByteArray(54, 55) // laces
+    ), false);
+    long doublePageSize = 2 * (input.getLength() + 54 + 55);
+    long expectedPosition = -doublePageSize + (targetGranule - headerGranule);
+    assertGetNextSeekPosition(expectedPosition, targetGranule, input);
+  }
+
+  public void testGetNextSeekPositionTooHighDistanceLower48000()
+      throws IOException, InterruptedException {
+    long targetGranule = 199999;
+    long headerGranule = 200000;
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x00, headerGranule, 22, 2),
+        TestUtil.createByteArray(54, 55) // laces
+    ), false);
+    long doublePageSize = 2 * (input.getLength() + 54 + 55);
+    long expectedPosition = -doublePageSize - 1;
+    assertGetNextSeekPosition(expectedPosition, targetGranule, input);
+  }
+
+  public void testGetNextSeekPositionTooLow() throws IOException, InterruptedException {
+    long headerGranule = 200000;
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x00, headerGranule, 22, 2),
+        TestUtil.createByteArray(54, 55) // laces
+    ), false);
+    long targetGranule = 300000;
+    long expectedPosition = -(27 + 2 + 54 + 55) + (targetGranule - headerGranule);
+    assertGetNextSeekPosition(expectedPosition, targetGranule, input);
+  }
+
+  private void assertGetNextSeekPosition(long expectedPosition, long targetGranule,
+      FakeExtractorInput input) throws IOException, InterruptedException {
+    while (true) {
+      try {
+        assertEquals(expectedPosition, oggSeeker.getNextSeekPosition(targetGranule, input));
+        break;
+      } catch (FakeExtractorInput.SimulatedIOException e) {
+        // ignored
+      }
+    }
+  }
+
+}

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/OggUtilTest.java

@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2015 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 com.google.android.exoplayer.extractor.ogg;
+
+import com.google.android.exoplayer.extractor.ExtractorInput;
+import com.google.android.exoplayer.testutil.FakeExtractorInput;
+import com.google.android.exoplayer.testutil.FakeExtractorInput.SimulatedIOException;
+import com.google.android.exoplayer.testutil.TestUtil;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import junit.framework.TestCase;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.util.Random;
+
+/**
+ * Unit test for {@link OggUtil}.
+ */
+public final class OggUtilTest extends TestCase {
+
+  private Random random = new Random(0);
+
+  public void testReadBits() throws Exception {
+    assertEquals(0, OggUtil.readBits((byte) 0x00, 2, 2));
+    assertEquals(1, OggUtil.readBits((byte) 0x02, 1, 1));
+    assertEquals(15, OggUtil.readBits((byte) 0xF0, 4, 4));
+    assertEquals(1, OggUtil.readBits((byte) 0x80, 1, 7));
+  }
+
+  public void testPopulatePageHeader() throws IOException, InterruptedException {
+    FakeExtractorInput input = TestData.createInput(TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x01, 123456, 4, 2),
+        TestUtil.createByteArray(2, 2)
+    ), true);
+    OggUtil.PageHeader header = new OggUtil.PageHeader();
+    ParsableByteArray byteArray = new ParsableByteArray(27 + 2);
+    populatePageHeader(input, header, byteArray, false);
+
+    assertEquals(0x01, header.type);
+    assertEquals(27 + 2, header.headerSize);
+    assertEquals(4, header.bodySize);
+    assertEquals(2, header.pageSegmentCount);
+    assertEquals(123456, header.granulePosition);
+    assertEquals(4, header.pageSequenceNumber);
+    assertEquals(0x1000, header.streamSerialNumber);
+    assertEquals(0x100000, header.pageChecksum);
+    assertEquals(0, header.revision);
+  }
+
+  public void testPopulatePageHeaderQuiteOnExceptionLessThan27Bytes()
+      throws IOException, InterruptedException {
+    FakeExtractorInput input = TestData.createInput(TestUtil.createByteArray(2, 2), false);
+    OggUtil.PageHeader header = new OggUtil.PageHeader();
+    ParsableByteArray byteArray = new ParsableByteArray(27 + 2);
+    assertFalse(populatePageHeader(input, header, byteArray, true));
+  }
+
+  public void testPopulatePageHeaderQuiteOnExceptionNotOgg()
+      throws IOException, InterruptedException {
+    byte[] headerBytes = TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x01, 123456, 4, 2),
+        TestUtil.createByteArray(2, 2)
+    );
+    // change from 'O' to 'o'
+    headerBytes[0] = 'o';
+    FakeExtractorInput input = TestData.createInput(headerBytes, false);
+    OggUtil.PageHeader header = new OggUtil.PageHeader();
+    ParsableByteArray byteArray = new ParsableByteArray(27 + 2);
+    assertFalse(populatePageHeader(input, header, byteArray, true));
+  }
+
+  public void testPopulatePageHeaderQuiteOnExceptionWrongRevision()
+      throws IOException, InterruptedException {
+    byte[] headerBytes = TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x01, 123456, 4, 2),
+        TestUtil.createByteArray(2, 2)
+    );
+    // change revision from 0 to 1
+    headerBytes[4] = 0x01;
+    FakeExtractorInput input = TestData.createInput(headerBytes, false);
+    OggUtil.PageHeader header = new OggUtil.PageHeader();
+    ParsableByteArray byteArray = new ParsableByteArray(27 + 2);
+    assertFalse(populatePageHeader(input, header, byteArray, true));
+  }
+
+  private boolean populatePageHeader(FakeExtractorInput input, OggUtil.PageHeader header,
+      ParsableByteArray byteArray, boolean quite) throws IOException, InterruptedException {
+    while (true) {
+      try {
+        return OggUtil.populatePageHeader(input, header, byteArray, quite);
+      } catch (SimulatedIOException e) {
+        // ignored
+      }
+    }
+  }
+
+  public void testSkipToNextPage() throws Exception {
+    FakeExtractorInput extractorInput = createInput(
+        TestUtil.joinByteArrays(
+            TestUtil.buildTestData(4000, random),
+            new byte[]{'O', 'g', 'g', 'S'},
+            TestUtil.buildTestData(4000, random)
+        ), false);
+    skipToNextPage(extractorInput);
+    assertEquals(4000, extractorInput.getPosition());
+  }
+
+  public void testSkipToNextPageUnbounded() throws Exception {
+    FakeExtractorInput extractorInput = createInput(
+        TestUtil.joinByteArrays(
+            TestUtil.buildTestData(4000, random),
+            new byte[]{'O', 'g', 'g', 'S'},
+            TestUtil.buildTestData(4000, random)
+        ), true);
+    skipToNextPage(extractorInput);
+    assertEquals(4000, extractorInput.getPosition());
+  }
+
+  public void testSkipToNextPageOverlap() throws Exception {
+    FakeExtractorInput extractorInput = createInput(
+        TestUtil.joinByteArrays(
+            TestUtil.buildTestData(2046, random),
+            new byte[]{'O', 'g', 'g', 'S'},
+            TestUtil.buildTestData(4000, random)
+        ), false);
+    skipToNextPage(extractorInput);
+    assertEquals(2046, extractorInput.getPosition());
+  }
+
+  public void testSkipToNextPageOverlapUnbounded() throws Exception {
+    FakeExtractorInput extractorInput = createInput(
+        TestUtil.joinByteArrays(
+            TestUtil.buildTestData(2046, random),
+            new byte[]{'O', 'g', 'g', 'S'},
+            TestUtil.buildTestData(4000, random)
+        ), true);
+    skipToNextPage(extractorInput);
+    assertEquals(2046, extractorInput.getPosition());
+  }
+
+  public void testSkipToNextPageInputShorterThanPeekLength() throws Exception {
+    FakeExtractorInput extractorInput = createInput(
+        TestUtil.joinByteArrays(
+            new byte[]{'x', 'O', 'g', 'g', 'S'}
+        ), false);
+    skipToNextPage(extractorInput);
+    assertEquals(1, extractorInput.getPosition());
+  }
+
+  public void testSkipToNextPageNoMatch() throws Exception {
+    FakeExtractorInput extractorInput = createInput(new byte[]{'g', 'g', 'S', 'O', 'g', 'g'},
+        false);
+    try {
+      skipToNextPage(extractorInput);
+      fail();
+    } catch (EOFException e) {
+      // expected
+    }
+  }
+
+  private static void skipToNextPage(ExtractorInput extractorInput)
+      throws IOException, InterruptedException {
+    while (true) {
+      try {
+        OggUtil.skipToNextPage(extractorInput);
+        break;
+      } catch (SimulatedIOException e) { /* ignored */ }
+    }
+  }
+
+  private static FakeExtractorInput createInput(byte[] data, boolean simulateUnknownLength) {
+    return new FakeExtractorInput.Builder().setData(data).setSimulateIOErrors(true)
+        .setSimulateUnknownLength(simulateUnknownLength).setSimulatePartialReads(true).build();
+  }
+}
+

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/OggVorbisExtractorTest.java

@@ -43,15 +43,36 @@ public final class OggVorbisExtractorTest extends TestCase {
   public void testSniff() throws Exception {
     byte[] data = TestUtil.joinByteArrays(
         TestData.buildOggHeader(0x02, 0, 1000, 0x02),
-        TestUtil.createByteArray(120, 120)); // Laces
+        TestUtil.createByteArray(120, 120),  // Laces
+        new byte[]{0x01, 'v', 'o', 'r', 'b', 'i', 's'});
     assertTrue(sniff(createInput(data)));
   }
 
-  public void testSniffFails() throws Exception {
+  public void testSniffFailsOpusFile() throws Exception {
+    byte[] data = TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x02, 0, 1000, 0x00),
+        new byte[]{'O', 'p', 'u', 's'});
+    assertFalse(sniff(createInput(data)));
+  }
+
+  public void testSniffFailsInvalidOggHeader() throws Exception {
     byte[] data = TestData.buildOggHeader(0x00, 0, 1000, 0x00);
     assertFalse(sniff(createInput(data)));
   }
 
+  public void testSniffInvalidVorbisHeader() throws Exception {
+    byte[] data = TestUtil.joinByteArrays(
+        TestData.buildOggHeader(0x02, 0, 1000, 0x02),
+        TestUtil.createByteArray(120, 120),  // Laces
+        new byte[]{0x01, 'X', 'o', 'r', 'b', 'i', 's'});
+    assertFalse(sniff(createInput(data)));
+  }
+
+  public void testSniffFailsEOF() throws Exception {
+    byte[] data = TestData.buildOggHeader(0x02, 0, 1000, 0x00);
+    assertFalse(sniff(createInput(data)));
+  }
+
   public void testAppendNumberOfSamples() throws Exception {
     ParsableByteArray buffer = new ParsableByteArray(4);
     buffer.setLimit(0);

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/TestData.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer.extractor.ogg;
 
+import com.google.android.exoplayer.testutil.FakeExtractorInput;
 import com.google.android.exoplayer.testutil.TestUtil;
 
 /**
@@ -22,6 +23,11 @@ import com.google.android.exoplayer.testutil.TestUtil;
  */
 /* package */ final class TestData {
 
+  /* package */ static FakeExtractorInput createInput(byte[] data, boolean simulateUnkownLength) {
+    return new FakeExtractorInput.Builder().setData(data).setSimulateIOErrors(true)
+        .setSimulateUnknownLength(simulateUnkownLength).setSimulatePartialReads(true).build();
+  }
+
   public static byte[] buildOggHeader(int headerType, long granule, int pageSequenceCounter,
       int pageSegmentCount) {
     return TestUtil.createByteArray(
@@ -46,7 +52,7 @@ import com.google.android.exoplayer.testutil.TestUtil;
         (pageSequenceCounter >> 24) & 0xFF,
         0x00, // LSB of page checksum.
         0x00,
-        0x00,
+        0x10,
         0x00, // MSB of page checksum.
         pageSegmentCount);
   }

library/src/androidTest/java/com/google/android/exoplayer/extractor/ogg/VorbisUtilTest.java

@@ -38,13 +38,6 @@ public final class VorbisUtilTest extends TestCase {
     assertEquals(0, VorbisUtil.iLog(-122));
   }
 
-  public void testReadBits() throws Exception {
-    assertEquals(0, VorbisUtil.readBits((byte) 0x00, 2, 2));
-    assertEquals(1, VorbisUtil.readBits((byte) 0x02, 1, 1));
-    assertEquals(15, VorbisUtil.readBits((byte) 0xF0, 4, 4));
-    assertEquals(1, VorbisUtil.readBits((byte) 0x80, 1, 7));
-  }
-
   public void testReadIdHeader() throws Exception {
     byte[] data = TestData.getIdentificationHeaderData();
     ParsableByteArray headerData = new ParsableByteArray(data, data.length);
@@ -95,4 +88,45 @@ public final class VorbisUtilTest extends TestCase {
     assertEquals(0, modes[1].windowType);
   }
 
+  public void testVerifyVorbisHeaderCapturePattern() throws ParserException {
+    ParsableByteArray header = new ParsableByteArray(
+        new byte[]{0x01, 'v', 'o', 'r', 'b', 'i', 's'});
+    assertEquals(true, VorbisUtil.verifyVorbisHeaderCapturePattern(0x01, header, false));
+  }
+
+  public void testVerifyVorbisHeaderCapturePatternInvalidHeader() throws ParserException {
+    ParsableByteArray header = new ParsableByteArray(
+        new byte[]{0x01, 'v', 'o', 'r', 'b', 'i', 's'});
+    try {
+      VorbisUtil.verifyVorbisHeaderCapturePattern(0x99, header, false);
+      fail();
+    } catch (ParserException e) {
+      assertEquals("expected header type 99", e.getMessage());
+    }
+  }
+
+  public void testVerifyVorbisHeaderCapturePatternInvalidHeaderQuite() throws ParserException {
+    ParsableByteArray header = new ParsableByteArray(
+        new byte[]{0x01, 'v', 'o', 'r', 'b', 'i', 's'});
+    assertFalse(VorbisUtil.verifyVorbisHeaderCapturePattern(0x99, header, true));
+  }
+
+  public void testVerifyVorbisHeaderCapturePatternInvalidPattern() throws ParserException {
+    ParsableByteArray header = new ParsableByteArray(
+        new byte[]{0x01, 'x', 'v', 'o', 'r', 'b', 'i', 's'});
+    try {
+      VorbisUtil.verifyVorbisHeaderCapturePattern(0x01, header, false);
+      fail();
+    } catch (ParserException e) {
+      assertEquals("expected characters 'vorbis'", e.getMessage());
+    }
+  }
+
+  public void testVerifyVorbisHeaderCapturePatternQuiteInvalidPatternQuite()
+      throws ParserException {
+    ParsableByteArray header = new ParsableByteArray(
+        new byte[]{0x01, 'x', 'v', 'o', 'r', 'b', 'i', 's'});
+    assertFalse(VorbisUtil.verifyVorbisHeaderCapturePattern(0x01, header, true));
+  }
+
 }

library/src/main/java/com/google/android/exoplayer/extractor/ogg/OggReader.java

@@ -15,11 +15,12 @@
  */
 package com.google.android.exoplayer.extractor.ogg;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.ParserException;
 import com.google.android.exoplayer.extractor.ExtractorInput;
+import com.google.android.exoplayer.extractor.ogg.OggUtil.PacketInfoHolder;
 import com.google.android.exoplayer.util.Assertions;
 import com.google.android.exoplayer.util.ParsableByteArray;
-import com.google.android.exoplayer.util.Util;
 
 import java.io.IOException;
 
@@ -28,12 +29,14 @@ import java.io.IOException;
  */
 /* package */ final class OggReader {
 
-  private static final String CAPTURE_PATTERN_PAGE = "OggS";
+  public static final int OGG_MAX_SEGMENT_SIZE = 255;
 
-  private final PageHeader pageHeader = new PageHeader();
+  private final OggUtil.PageHeader pageHeader = new OggUtil.PageHeader();
   private final ParsableByteArray headerArray = new ParsableByteArray(27 + 255);
+  private final PacketInfoHolder holder = new PacketInfoHolder();
 
   private int currentSegmentIndex = -1;
+  private long elapsedSamples;
 
   /**
    * Resets this reader.
@@ -65,37 +68,99 @@ import java.io.IOException;
     while (!packetComplete) {
       if (currentSegmentIndex < 0) {
         // We're at the start of a page.
-        if (!populatePageHeader(input, pageHeader, headerArray, false)) {
+        if (!OggUtil.populatePageHeader(input, pageHeader, headerArray, true)) {
           return false;
         }
-        currentSegmentIndex = 0;
+        int segmentIndex = 0;
-      }
+        int bytesToSkip = pageHeader.headerSize;
-
+        if ((pageHeader.type & 0x01) == 0x01 && packetArray.limit() == 0) {
-      int packetSize = 0;
+          // After seeking, the first packet may be the remainder
-      int segmentIndex = currentSegmentIndex;
+          // part of a continued packet which has to be discarded.
-      // add up packetSize from laces
+          OggUtil.calculatePacketSize(pageHeader, segmentIndex, holder);
-      while (segmentIndex < pageHeader.pageSegmentCount) {
+          segmentIndex += holder.segmentCount;
-        int segmentLength = pageHeader.laces[segmentIndex++];
+          bytesToSkip += holder.size;
-        packetSize += segmentLength;
-        if (segmentLength != 255) {
-          // packets end at first lace < 255
-          break;
         }
+        input.skipFully(bytesToSkip);
+        currentSegmentIndex = segmentIndex;
       }
 
-      if (packetSize > 0) {
+      OggUtil.calculatePacketSize(pageHeader, currentSegmentIndex, holder);
-        input.readFully(packetArray.data, packetArray.limit(), packetSize);
+      int segmentIndex = currentSegmentIndex + holder.segmentCount;
-        packetArray.setLimit(packetArray.limit() + packetSize);
+      if (holder.size > 0) {
+        input.readFully(packetArray.data, packetArray.limit(), holder.size);
+        packetArray.setLimit(packetArray.limit() + holder.size);
         packetComplete = pageHeader.laces[segmentIndex - 1] != 255;
       }
       // advance now since we are sure reading didn't throw an exception
-      currentSegmentIndex = segmentIndex == pageHeader.pageSegmentCount ? -1 : segmentIndex;
+      currentSegmentIndex = segmentIndex == pageHeader.pageSegmentCount ? -1
+          : segmentIndex;
     }
     return true;
   }
 
   /**
-   * Returns the {@link OggReader.PageHeader} of the current page. The header might not have been
+   * Skips to the last Ogg page in the stream and reads the header's granule field which is the
+   * total number of samples per channel.
+   *
+   * @param input The {@link ExtractorInput} to read from.
+   * @return the total number of samples of this input.
+   * @throws IOException thrown if reading from the input fails.
+   * @throws InterruptedException thrown if interrupted while reading from the input.
+   */
+  public long readGranuleOfLastPage(ExtractorInput input)
+      throws IOException, InterruptedException {
+    Assertions.checkArgument(input.getLength() != C.LENGTH_UNBOUNDED); // never read forever!
+    OggUtil.skipToNextPage(input);
+    pageHeader.reset();
+    while ((pageHeader.type & 0x04) != 0x04) {
+      if (pageHeader.bodySize > 0) {
+        input.skipFully(pageHeader.bodySize);
+      }
+      OggUtil.populatePageHeader(input, pageHeader, headerArray, false);
+      input.skipFully(pageHeader.headerSize);
+    }
+    return pageHeader.granulePosition;
+  }
+
+  /**
+   * Skips to the position of the start of the page containing the {@code targetGranule} and
+   * returns the elapsed samples which is the granule of the page previous to the target page.
+   * <p>
+   * Note that the position of the {@code input} must be before the start of the page previous to
+   * the page containing the targetGranule to get the correct number of elapsed samples.
+   * Which is in short like: {@code pos(input) <= pos(targetPage.pageSequence - 1)}.
+   *
+   * @param input the {@link ExtractorInput} to read from.
+   * @param targetGranule the target granule (number of frames per channel).
+   * @return the number of elapsed samples at the start of the target page.
+   * @throws ParserException thrown if populating the page header fails.
+   * @throws IOException thrown if reading from the input fails.
+   * @throws InterruptedException thrown if interrupted while reading from the input.
+   */
+  public long skipToPageOfGranule(ExtractorInput input, long targetGranule)
+      throws IOException, InterruptedException {
+    OggUtil.skipToNextPage(input);
+    OggUtil.populatePageHeader(input, pageHeader, headerArray, false);
+    while (pageHeader.granulePosition < targetGranule) {
+      input.skipFully(pageHeader.headerSize + pageHeader.bodySize);
+      // Store in a member field to be able to resume after IOExceptions.
+      elapsedSamples = pageHeader.granulePosition;
+      // Peek next header.
+      OggUtil.populatePageHeader(input, pageHeader, headerArray, false);
+    }
+    if (elapsedSamples == 0) {
+      throw new ParserException();
+    }
+    input.resetPeekPosition();
+    long returnValue = elapsedSamples;
+    // Reset member state.
+    elapsedSamples = 0;
+    currentSegmentIndex = -1;
+    return returnValue;
+  }
+
+  /**
+   * Returns the {@link OggUtil.PageHeader} of the current page. The header might not have been
    * populated if the first packet has yet to be read.
    * <p>
    * Note that there is only a single instance of {@code OggReader.PageHeader} which is mutable.
@@ -104,93 +169,8 @@ import java.io.IOException;
    *
    * @return the {@code PageHeader} of the current page or {@code null}.
    */
-  public PageHeader getPageHeader() {
+  public OggUtil.PageHeader getPageHeader() {
     return pageHeader;
   }
 
-  /**
-   * Reads/peeks an Ogg page header and stores the data in the {@code header} object passed
-   * as argument.
-   *
-   * @param input the {@link ExtractorInput} to read from.
-   * @param header the {@link PageHeader} to read from.
-   * @param scratch a scratch array temporary use.
-   * @param peek pass {@code true} if data should only be peeked from current peek position.
-   * @return {@code true} if the read was successful. {@code false} if the end of the
-   *     input was encountered having read no data.
-   * @throws IOException thrown if reading data fails or the stream is invalid.
-   * @throws InterruptedException thrown if thread is interrupted when reading/peeking.
-   */
-  public static boolean populatePageHeader(ExtractorInput input, PageHeader header,
-      ParsableByteArray scratch, boolean peek) throws IOException, InterruptedException {
-
-    scratch.reset();
-    header.reset();
-    if (!input.peekFully(scratch.data, 0, 27, true)) {
-      return false;
-    }
-    if (scratch.readUnsignedInt() != Util.getIntegerCodeForString(CAPTURE_PATTERN_PAGE)) {
-      throw new ParserException("expected OggS capture pattern at begin of page");
-    }
-
-    header.revision = scratch.readUnsignedByte();
-    if (header.revision != 0x00) {
-      throw new ParserException("unsupported bit stream revision");
-    }
-    header.type = scratch.readUnsignedByte();
-
-    header.granulePosition = scratch.readLittleEndianLong();
-    header.streamSerialNumber = scratch.readLittleEndianUnsignedInt();
-    header.pageSequenceNumber = scratch.readLittleEndianUnsignedInt();
-    header.pageChecksum = scratch.readLittleEndianUnsignedInt();
-    header.pageSegmentCount = scratch.readUnsignedByte();
-
-    scratch.reset();
-    // calculate total size of header including laces
-    header.headerSize = 27 + header.pageSegmentCount;
-    input.peekFully(scratch.data, 0, header.pageSegmentCount);
-    for (int i = 0; i < header.pageSegmentCount; i++) {
-      header.laces[i] = scratch.readUnsignedByte();
-      header.bodySize += header.laces[i];
-    }
-    if (!peek) {
-      input.skipFully(header.headerSize);
-    }
-    return true;
-  }
-
-  /**
-   * Data object to store header information. Be aware that {@code laces.length} is always 255.
-   * Instead use {@code pageSegmentCount} to iterate.
-   */
-  public static final class PageHeader {
-
-    public int revision;
-    public int type;
-    public long granulePosition;
-    public long streamSerialNumber;
-    public long pageSequenceNumber;
-    public long pageChecksum;
-    public int pageSegmentCount;
-    public int headerSize;
-    public int bodySize;
-    public int[] laces = new int[255];
-
-    /**
-     * Resets all primitive member fields to zero.
-     */
-    public void reset() {
-      revision = 0;
-      type = 0;
-      granulePosition = 0;
-      streamSerialNumber = 0;
-      pageSequenceNumber = 0;
-      pageChecksum = 0;
-      pageSegmentCount = 0;
-      headerSize = 0;
-      bodySize = 0;
-    }
-
-  }
-
 }

library/src/main/java/com/google/android/exoplayer/extractor/ogg/OggSeeker.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2015 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 com.google.android.exoplayer.extractor.ogg;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.extractor.ExtractorInput;
+import com.google.android.exoplayer.util.Assertions;
+import com.google.android.exoplayer.util.ParsableByteArray;
+
+import java.io.IOException;
+
+/**
+ * Used to seek in an Ogg stream.
+ */
+/* package */ final class OggSeeker {
+
+  private static final int MATCH_RANGE = 72000;
+
+  private final OggUtil.PageHeader pageHeader = new OggUtil.PageHeader();
+  private final ParsableByteArray headerArray = new ParsableByteArray(27 + 255);
+  private long audioDataLength = C.LENGTH_UNBOUNDED;
+  private long totalSamples;
+
+  /**
+   * Setup the seeker with the data it needs to to an educated guess of seeking positions.
+   *
+   * @param audioDataLength the length of the audio data (total bytes - header bytes).
+   * @param totalSamples the total number of samples of audio data.
+   */
+  public void setup(long audioDataLength, long totalSamples) {
+    Assertions.checkArgument(audioDataLength > 0 && totalSamples > 0);
+    this.audioDataLength = audioDataLength;
+    this.totalSamples = totalSamples;
+  }
+
+  /**
+   * Resets this {@code OggSeeker}.
+   */
+  public void reset() {
+    pageHeader.reset();
+    headerArray.reset();
+  }
+
+  /**
+   * Returns a position converging to the {@code targetGranule} to which the {@link ExtractorInput}
+   * has to seek and then be passed for another call until -1 is return. If -1 is returned the
+   * input is at a position which is before the start of the page before the target page and at
+   * which it is sensible to just skip pages to the target granule and pre-roll instead of doing
+   * another seek request.
+   *
+   * @param targetGranule the target granule position to seek to.
+   * @param input the {@link ExtractorInput} to read from.
+   * @return the position to seek the {@link ExtractorInput} to for a next call or -1 if it's close
+   *    enough to skip to the target page.
+   * @throws IOException thrown if reading from the input fails.
+   * @throws InterruptedException thrown if interrupted while reading from the input.
+   */
+  public long getNextSeekPosition(long targetGranule, ExtractorInput input)
+      throws IOException, InterruptedException {
+    Assertions.checkState(audioDataLength != C.LENGTH_UNBOUNDED && totalSamples != 0);
+    OggUtil.populatePageHeader(input, pageHeader, headerArray, false);
+    long granuleDistance = targetGranule - pageHeader.granulePosition;
+    if (granuleDistance <= 0 || granuleDistance > MATCH_RANGE) {
+      // estimated position too high or too low
+      long offset = (pageHeader.bodySize + pageHeader.headerSize)
+          * (granuleDistance <= 0 ? 2 : 1);
+      return input.getPosition() - offset + (granuleDistance * audioDataLength / totalSamples);
+    }
+    // position accepted (below target granule and within MATCH_RANGE)
+    input.resetPeekPosition();
+    return -1;
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/extractor/ogg/OggUtil.java

@@ -0,0 +1,209 @@
+/*
+ * Copyright (C) 2015 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 com.google.android.exoplayer.extractor.ogg;
+
+import com.google.android.exoplayer.C;
+import com.google.android.exoplayer.ParserException;
+import com.google.android.exoplayer.extractor.ExtractorInput;
+import com.google.android.exoplayer.util.ParsableByteArray;
+import com.google.android.exoplayer.util.Util;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+/**
+ * Utility methods for reading ogg streams.
+ */
+/* package */ final class OggUtil {
+
+  private static final int TYPE_OGGS = Util.getIntegerCodeForString("OggS");
+
+  /**
+   * Reads an int of {@code length} bits from {@code src} starting at
+   * {@code leastSignificantBitIndex}.
+   *
+   * @param src the {@code byte} to read from.
+   * @param length the length in bits of the int to read.
+   * @param leastSignificantBitIndex the index of the least significant bit of the int to read.
+   * @return the int value read.
+   */
+  public static int readBits(byte src, int length, int leastSignificantBitIndex) {
+    return (src >> leastSignificantBitIndex) & (255 >>> (8 - length));
+  }
+
+  /**
+   * Skips to the next page.
+   *
+   * @param input The {@code ExtractorInput} to skip to the next page.
+   * @throws IOException thrown if peeking/reading from the input fails.
+   * @throws InterruptedException thrown if interrupted while peeking/reading from the input.
+   */
+  public static void skipToNextPage(ExtractorInput input)
+      throws IOException, InterruptedException {
+
+    byte[] buffer = new byte[2048];
+    int peekLength = buffer.length;
+    while (true) {
+      if (input.getLength() != C.LENGTH_UNBOUNDED
+          && input.getPosition() + peekLength > input.getLength()) {
+        // Make sure to not peek beyond the end of the input.
+        peekLength = (int) (input.getLength() - input.getPosition());
+        if (peekLength < 4) {
+          // Not found until eof.
+          throw new EOFException();
+        }
+      }
+      input.peekFully(buffer, 0, peekLength, false);
+      for (int i = 0; i < peekLength - 3; i++) {
+        if (buffer[i] == 'O' && buffer[i + 1] == 'g' && buffer[i + 2] == 'g'
+            && buffer[i + 3] == 'S') {
+          // Match! Skip to the start of the pattern.
+          input.skipFully(i);
+          return;
+        }
+      }
+      // Overlap by not skipping the entire peekLength.
+      input.skipFully(peekLength - 3);
+    }
+  }
+
+  /**
+   * Peeks an Ogg page header and stores the data in the {@code header} object passed
+   * as argument.
+   *
+   * @param input the {@link ExtractorInput} to read from.
+   * @param header the {@link PageHeader} to read from.
+   * @param scratch a scratch array temporary use.
+   * @param quite if {@code true} no Exceptions are thrown but {@code false} is return if something
+   *     goes wrong.
+   * @return {@code true} if the read was successful. {@code false} if the end of the
+   *     input was encountered having read no data.
+   * @throws IOException thrown if reading data fails or the stream is invalid.
+   * @throws InterruptedException thrown if thread is interrupted when reading/peeking.
+   */
+  public static boolean populatePageHeader(ExtractorInput input, PageHeader header,
+      ParsableByteArray scratch, boolean quite) throws IOException, InterruptedException {
+
+    scratch.reset();
+    header.reset();
+    boolean hasEnoughBytes = input.getLength() == C.LENGTH_UNBOUNDED
+        || input.getLength() - input.getPeekPosition() >= 27;
+    if (!hasEnoughBytes || !input.peekFully(scratch.data, 0, 27, true)) {
+      if (quite) {
+        return false;
+      } else {
+        throw new EOFException();
+      }
+    }
+    if (scratch.readUnsignedInt() != TYPE_OGGS) {
+      if (quite) {
+        return false;
+      } else {
+        throw new ParserException("expected OggS capture pattern at begin of page");
+      }
+    }
+
+    header.revision = scratch.readUnsignedByte();
+    if (header.revision != 0x00) {
+      if (quite) {
+        return false;
+      } else {
+        throw new ParserException("unsupported bit stream revision");
+      }
+    }
+    header.type = scratch.readUnsignedByte();
+
+    header.granulePosition = scratch.readLittleEndianLong();
+    header.streamSerialNumber = scratch.readLittleEndianUnsignedInt();
+    header.pageSequenceNumber = scratch.readLittleEndianUnsignedInt();
+    header.pageChecksum = scratch.readLittleEndianUnsignedInt();
+    header.pageSegmentCount = scratch.readUnsignedByte();
+
+    scratch.reset();
+    // calculate total size of header including laces
+    header.headerSize = 27 + header.pageSegmentCount;
+    input.peekFully(scratch.data, 0, header.pageSegmentCount);
+    for (int i = 0; i < header.pageSegmentCount; i++) {
+      header.laces[i] = scratch.readUnsignedByte();
+      header.bodySize += header.laces[i];
+    }
+    return true;
+  }
+
+  /**
+   * Calculates the size of the packet starting from {@code startSegmentIndex}.
+   *
+   * @param header the {@link PageHeader} with laces.
+   * @param startSegmentIndex the index of the first segment of the packet.
+   * @param holder a position holder to store the resulting size value.
+   */
+  public static void calculatePacketSize(PageHeader header, int startSegmentIndex,
+      PacketInfoHolder holder) {
+    holder.segmentCount = 0;
+    holder.size = 0;
+    while (startSegmentIndex + holder.segmentCount < header.pageSegmentCount) {
+      int segmentLength = header.laces[startSegmentIndex + holder.segmentCount++];
+      holder.size += segmentLength;
+      if (segmentLength != 255) {
+        // packets end at first lace < 255
+        break;
+      }
+    }
+  }
+
+  /**
+   * Data object to store header information. Be aware that {@code laces.length} is always 255.
+   * Instead use {@code pageSegmentCount} to iterate.
+   */
+  public static final class PageHeader {
+
+    public int revision;
+    public int type;
+    public long granulePosition;
+    public long streamSerialNumber;
+    public long pageSequenceNumber;
+    public long pageChecksum;
+    public int pageSegmentCount;
+    public int headerSize;
+    public int bodySize;
+    public final int[] laces = new int[255];
+
+    /**
+     * Resets all primitive member fields to zero.
+     */
+    public void reset() {
+      revision = 0;
+      type = 0;
+      granulePosition = 0;
+      streamSerialNumber = 0;
+      pageSequenceNumber = 0;
+      pageChecksum = 0;
+      pageSegmentCount = 0;
+      headerSize = 0;
+      bodySize = 0;
+    }
+
+  }
+
+  /**
+   * Holds size and number of segments of a packet.
+   */
+  public static class PacketInfoHolder {
+    public int size;
+    public int segmentCount;
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/extractor/ogg/OggVorbisExtractor.java

@@ -25,27 +25,21 @@ import com.google.android.exoplayer.extractor.PositionHolder;
 import com.google.android.exoplayer.extractor.SeekMap;
 import com.google.android.exoplayer.extractor.TrackOutput;
 import com.google.android.exoplayer.extractor.ogg.VorbisUtil.Mode;
-import com.google.android.exoplayer.extractor.ogg.VorbisUtil.VorbisIdHeader;
 import com.google.android.exoplayer.util.MimeTypes;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
-import android.util.Log;
-
 import java.io.IOException;
 import java.util.ArrayList;
 
 /**
  * {@link Extractor} to extract Vorbis data out of Ogg byte stream.
  */
-public final class OggVorbisExtractor implements Extractor {
+public final class OggVorbisExtractor implements Extractor, SeekMap {
-
-  private static final String TAG = "OggVorbisExtractor";
-
-  private static final int OGG_MAX_SEGMENT_SIZE = 255;
 
   private final ParsableByteArray scratch = new ParsableByteArray(
-      new byte[OGG_MAX_SEGMENT_SIZE * 255], 0);
+      new byte[OggReader.OGG_MAX_SEGMENT_SIZE * 255], 0);
-  private final OggReader oggReader =  new OggReader();
+
+  private final OggReader oggReader = new OggReader();
 
   private TrackOutput trackOutput;
   private VorbisSetup vorbisSetup;
@@ -53,36 +47,48 @@ public final class OggVorbisExtractor implements Extractor {
   private long elapsedSamples;
   private boolean seenFirstAudioPacket;
 
+  private final OggSeeker oggSeeker = new OggSeeker();
+  private long targetGranule = -1;
+
+  private ExtractorOutput extractorOutput;
   private VorbisUtil.VorbisIdHeader vorbisIdHeader;
   private VorbisUtil.CommentHeader commentHeader;
+  private long inputLength;
+  private long audioStartPosition;
+  private long totalSamples;
+  private long durationUs;
 
   @Override
   public boolean sniff(ExtractorInput input) throws IOException, InterruptedException {
     try {
-      OggReader.PageHeader header = new OggReader.PageHeader();
+      OggUtil.PageHeader header = new OggUtil.PageHeader();
-      OggReader.populatePageHeader(input, header, scratch, true);
+      if (!OggUtil.populatePageHeader(input, header, scratch, true)
-      if ((header.type & 0x02) != 0x02) {
+          || (header.type & 0x02) != 0x02 || header.bodySize < 7) {
-        throw new ParserException("expected page to be first page of a logical stream");
+        return false;
       }
-      input.resetPeekPosition();
+      scratch.reset();
+      input.peekFully(scratch.data, 0, 7);
+      return VorbisUtil.verifyVorbisHeaderCapturePattern(0x01, scratch, true);
     } catch (ParserException e) {
-      Log.e(TAG, e.getMessage());
+      // does not happen
-      return false;
+    } finally {
+      input.resetPeekPosition();
+      scratch.reset();
     }
-    return true;
+    return false;
   }
 
   @Override
   public void init(ExtractorOutput output) {
     trackOutput = output.track(0);
     output.endTracks();
-    output.seekMap(new SeekMap.Unseekable(C.UNKNOWN_TIME_US));
+    extractorOutput = output;
   }
 
   @Override
   public void seek() {
     oggReader.reset();
-    previousPacketBlockSize = -1;
+    previousPacketBlockSize = 0;
     elapsedSamples = 0;
     seenFirstAudioPacket = false;
     scratch.reset();
@@ -92,35 +98,77 @@ public final class OggVorbisExtractor implements Extractor {
   public int read(ExtractorInput input, PositionHolder seekPosition)
       throws IOException, InterruptedException {
 
-    if (vorbisSetup == null) {
+    // Setup.
-      vorbisSetup = readSetupHeaders(input, scratch);
+    if (totalSamples == 0) {
-      VorbisIdHeader idHeader = vorbisSetup.idHeader;
+      if (vorbisSetup == null) {
-      ArrayList<byte[]> codecInitializationData = new ArrayList<>();
+        inputLength = input.getLength();
-      codecInitializationData.clear();
+        vorbisSetup = readSetupHeaders(input, scratch);
-      codecInitializationData.add(idHeader.data);
+        audioStartPosition = input.getPosition();
-      codecInitializationData.add(vorbisSetup.setupHeaderData);
+        // Output the format.
-      trackOutput.format(Format.createAudioSampleFormat(null, MimeTypes.AUDIO_VORBIS,
+        ArrayList<byte[]> codecInitialisationData = new ArrayList<>();
-          idHeader.bitrateNominal, OGG_MAX_SEGMENT_SIZE * 255, idHeader.channels,
+        codecInitialisationData.add(vorbisSetup.idHeader.data);
-          idHeader.sampleRate, codecInitializationData, null));
+        codecInitialisationData.add(vorbisSetup.setupHeaderData);
+        trackOutput.format(Format.createAudioSampleFormat(null, MimeTypes.AUDIO_VORBIS,
+            vorbisSetup.idHeader.bitrateNominal, OggReader.OGG_MAX_SEGMENT_SIZE * 255,
+            vorbisSetup.idHeader.channels, (int) vorbisSetup.idHeader.sampleRate,
+            codecInitialisationData, null));
+        if (inputLength == C.LENGTH_UNBOUNDED) {
+          // If the length is unbounded, we cannot determine the duration or seek.
+          totalSamples = -1;
+          durationUs = C.LENGTH_UNBOUNDED;
+          extractorOutput.seekMap(this);
+          return RESULT_CONTINUE;
+        }
+        // Seek to just before the last page of stream to get the duration.
+        seekPosition.position = input.getLength() - 8000;
+        return RESULT_SEEK;
+      }
+
+      totalSamples = oggReader.readGranuleOfLastPage(input);
+      durationUs = totalSamples * C.MICROS_PER_SECOND / vorbisSetup.idHeader.sampleRate;
+      oggSeeker.setup(inputLength - audioStartPosition, totalSamples);
+      extractorOutput.seekMap(this);
+      // Seek back to resume from where we finished reading vorbis headers.
+      seekPosition.position = audioStartPosition;
+      return RESULT_SEEK;
     }
+
+    // Seeking requested.
+    if (!seenFirstAudioPacket && targetGranule > -1) {
+      OggUtil.skipToNextPage(input);
+      long position = oggSeeker.getNextSeekPosition(targetGranule, input);
+      if (position != -1) {
+        seekPosition.position = position;
+        return RESULT_SEEK;
+      } else {
+        elapsedSamples = oggReader.skipToPageOfGranule(input, targetGranule);
+        previousPacketBlockSize = vorbisIdHeader.blockSize0;
+        // We're never at the first packet after seeking.
+        seenFirstAudioPacket = true;
+        oggSeeker.reset();
+      }
+    }
+
+    // Playback.
     if (oggReader.readPacket(input, scratch)) {
-      // if this is an audio packet...
+      // If this is an audio packet...
       if ((scratch.data[0] & 0x01) != 1) {
-        // ... we need to decode the block size
+        // ... Then we need to decode the block size
         int packetBlockSize = decodeBlockSize(scratch.data[0], vorbisSetup);
-        // a packet contains samples produced from overlapping the previous and current frame data
+        // A packet contains samples produced from overlapping the previous and current frame data
-        // (https://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-350001.3.2)
+        // (https://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-350001.3.2).
-        int samplesInPacket = seenFirstAudioPacket ? (packetBlockSize + previousPacketBlockSize) / 4
+        int samplesInPacket = seenFirstAudioPacket
-            : 0;
+            ? ((packetBlockSize + previousPacketBlockSize) / 4) : 0;
-        // codec expects the number of samples appended to audio data
+        if (elapsedSamples + samplesInPacket >= targetGranule) {
-        appendNumberOfSamples(scratch, samplesInPacket);
+          // Codec expects the number of samples appended to audio data.
-
+          appendNumberOfSamples(scratch, samplesInPacket);
-        // calculate time and send audio data to codec
+          // Calculate time and send audio data to codec.
-        long timeUs = elapsedSamples * C.MICROS_PER_SECOND / vorbisSetup.idHeader.sampleRate;
+          long timeUs = elapsedSamples * C.MICROS_PER_SECOND / vorbisSetup.idHeader.sampleRate;
-        trackOutput.sampleData(scratch, scratch.limit());
+          trackOutput.sampleData(scratch, scratch.limit());
-        trackOutput.sampleMetadata(timeUs, C.SAMPLE_FLAG_SYNC, scratch.limit(), 0, null);
+          trackOutput.sampleMetadata(timeUs, C.SAMPLE_FLAG_SYNC, scratch.limit(), 0, null);
-
+          targetGranule = -1;
-        // update state in members for next iteration
+        }
+        // Update state in members for next iteration.
         seenFirstAudioPacket = true;
         elapsedSamples += samplesInPacket;
         previousPacketBlockSize = packetBlockSize;
@@ -176,7 +224,7 @@ public final class OggVorbisExtractor implements Extractor {
 
   private static int decodeBlockSize(byte firstByteOfAudioPacket, VorbisSetup vorbisSetup) {
     // read modeNumber (https://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-730004.3.1)
-    int modeNumber = VorbisUtil.readBits(firstByteOfAudioPacket, vorbisSetup.iLogModes, 1);
+    int modeNumber = OggUtil.readBits(firstByteOfAudioPacket, vorbisSetup.iLogModes, 1);
     int currentBlockSize;
     if (!vorbisSetup.modes[modeNumber].blockFlag) {
       currentBlockSize = vorbisSetup.idHeader.blockSize0;
@@ -186,6 +234,31 @@ public final class OggVorbisExtractor implements Extractor {
     return currentBlockSize;
   }
 
+  // SeekMap implementation.
+
+  @Override
+  public boolean isSeekable() {
+    return inputLength != C.LENGTH_UNBOUNDED;
+  }
+
+  @Override
+  public long getDurationUs() {
+    return durationUs;
+  }
+
+  @Override
+  public long getPosition(long timeUs) {
+    if (timeUs == 0) {
+      targetGranule = -1;
+      return audioStartPosition;
+    }
+    targetGranule = vorbisSetup.idHeader.sampleRate * timeUs / C.MICROS_PER_SECOND;
+    return Math.max(audioStartPosition, ((inputLength - audioStartPosition) * timeUs
+        / durationUs) - 4000);
+  }
+
+  // Internal classes.
+
   /**
    * Class to hold all data read from Vorbis setup headers.
    */

library/src/main/java/com/google/android/exoplayer/extractor/ogg/VorbisUtil.java

@@ -46,19 +46,6 @@ import java.util.Arrays;
     return val;
   }
 
-  /**
-   * Reads an int of {@code length} bits from {@code src} starting at
-   * {@code leastSignificantBitIndex}.
-   *
-   * @param src the {@code byte} to read from.
-   * @param length the length in bits of the int to read.
-   * @param leastSignificantBitIndex the index of the least significant bit of the int to read.
-   * @return the int value read.
-   */
-  public static int readBits(byte src, int length, int leastSignificantBitIndex) {
-    return (src >> leastSignificantBitIndex) & (255 >>> (8 - length));
-  }
-
   /**
    * Reads a vorbis identification header from {@code headerData}.
    *
@@ -71,11 +58,11 @@ import java.util.Arrays;
   public static VorbisIdHeader readVorbisIdentificationHeader(ParsableByteArray headerData)
       throws ParserException {
 
-    captureVorbisHeader(0x01, headerData);
+    verifyVorbisHeaderCapturePattern(0x01, headerData, false);
 
     long version = headerData.readLittleEndianUnsignedInt();
     int channels = headerData.readUnsignedByte();
-    int sampleRate = (int) headerData.readLittleEndianUnsignedInt();
+    long sampleRate = headerData.readLittleEndianUnsignedInt();
     int bitrateMax = headerData.readLittleEndianInt();
     int bitrateNominal = headerData.readLittleEndianInt();
     int bitrateMin = headerData.readLittleEndianInt();
@@ -104,7 +91,8 @@ import java.util.Arrays;
   public static CommentHeader readVorbisCommentHeader(ParsableByteArray headerData)
       throws ParserException {
 
-    int length = captureVorbisHeader(0x03, headerData);
+    verifyVorbisHeaderCapturePattern(0x03, headerData, false);
+    int length = 7;
 
     int len = (int) headerData.readLittleEndianUnsignedInt();
     length += 4;
@@ -127,21 +115,40 @@ import java.util.Arrays;
     return new CommentHeader(vendor, comments, length);
   }
 
-  private static int captureVorbisHeader(int headerType, ParsableByteArray idHeader)
+  /**
+   * Verifies whether the next bytes in {@code header} are a vorbis header of the given
+   * {@code headerType}.
+   *
+   * @param headerType the type of the header expected.
+   * @param header the alleged header bytes.
+   * @param quite if {@code true} no exceptions are thrown. Instead {@code false} is returned.
+   * @return the number of bytes read.
+   * @throws ParserException thrown if header type or capture pattern is not as expected.
+   */
+  public static boolean verifyVorbisHeaderCapturePattern(int headerType, ParsableByteArray header,
+      boolean quite)
       throws ParserException {
-    if (idHeader.readUnsignedByte() != headerType) {
+    if (header.readUnsignedByte() != headerType) {
-      throw new ParserException("expected header type " + Integer.toHexString(headerType));
+      if (quite) {
+        return false;
+      } else {
+        throw new ParserException("expected header type " + Integer.toHexString(headerType));
+      }
     }
 
-    if (!(idHeader.readUnsignedByte() == 'v'
+    if (!(header.readUnsignedByte() == 'v'
-        && idHeader.readUnsignedByte() == 'o'
+        && header.readUnsignedByte() == 'o'
-        && idHeader.readUnsignedByte() == 'r'
+        && header.readUnsignedByte() == 'r'
-        && idHeader.readUnsignedByte() == 'b'
+        && header.readUnsignedByte() == 'b'
-        && idHeader.readUnsignedByte() == 'i'
+        && header.readUnsignedByte() == 'i'
-        && idHeader.readUnsignedByte() == 's')) {
+        && header.readUnsignedByte() == 's')) {
-      throw new ParserException("expected characters 'vorbis'");
+      if (quite) {
+        return false;
+      } else {
+        throw new ParserException("expected characters 'vorbis'");
+      }
     }
-    return 7; // bytes read
+    return true;
   }
 
   /**
@@ -159,7 +166,7 @@ import java.util.Arrays;
   public static Mode[] readVorbisModes(ParsableByteArray headerData, int channels)
       throws ParserException {
 
-    captureVorbisHeader(0x05, headerData);
+    verifyVorbisHeaderCapturePattern(0x05, headerData, false);
 
     int numberOfBooks = headerData.readUnsignedByte() + 1;
 
@@ -433,7 +440,7 @@ import java.util.Arrays;
 
     public final long version;
     public final int channels;
-    public final int sampleRate;
+    public final long sampleRate;
     public final int bitrateMax;
     public final int bitrateNominal;
     public final int bitrateMin;
@@ -442,7 +449,7 @@ import java.util.Arrays;
     public final boolean framingFlag;
     public final byte[] data;
 
-    public VorbisIdHeader(long version, int channels, int sampleRate, int bitrateMax,
+    public VorbisIdHeader(long version, int channels, long sampleRate, int bitrateMax,
         int bitrateNominal, int bitrateMin, int blockSize0, int blockSize1, boolean framingFlag,
         byte[] data) {
       this.version = version;