Merge pull request #9536 from TiVo:p-fix-issue-2882

PiperOrigin-RevId: 411056555

RELEASENOTES.md

@@ -11,6 +11,9 @@
     *   Add a method to `AdPlaybackState` to allow resetting an ad group so that
         it can be played again
         ([#9615](https://github.com/google/ExoPlayer/issues/9615)).
+*   HLS:
+    *   Support key-frame accurate seeking in HLS
+        ([#2882](https://github.com/google/ExoPlayer/issues/2882)).
 
 ### 2.16.1 (2021-11-18)
 

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsChunkSource.java

@@ -26,6 +26,7 @@ import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.SeekParameters;
 import com.google.android.exoplayer2.analytics.PlayerId;
 import com.google.android.exoplayer2.source.BehindLiveWindowException;
 import com.google.android.exoplayer2.source.TrackGroup;
@@ -241,6 +242,53 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     this.isTimestampMaster = isTimestampMaster;
   }
 
+  /**
+   * Adjusts a seek position given the specified {@link SeekParameters}.
+   *
+   * @param positionUs The seek position in microseconds.
+   * @param seekParameters Parameters that control how the seek is performed.
+   * @return The adjusted seek position, in microseconds.
+   */
+  public long getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) {
+    int selectedIndex = trackSelection.getSelectedIndex();
+    @Nullable
+    HlsMediaPlaylist mediaPlaylist =
+        selectedIndex < playlistUrls.length && selectedIndex != C.INDEX_UNSET
+            ? playlistTracker.getPlaylistSnapshot(
+                playlistUrls[selectedIndex], /* isForPlayback= */ true)
+            : null;
+
+    if (mediaPlaylist == null
+        || mediaPlaylist.segments.isEmpty()
+        || !mediaPlaylist.hasIndependentSegments) {
+      return positionUs;
+    }
+
+    // Segments start with sync samples (i.e., EXT-X-INDEPENDENT-SEGMENTS is set) and the playlist
+    // is non-empty, so we can use segment start times as sync points. Note that in the rare case
+    // that (a) an adaptive quality switch occurs between the adjustment and the seek being
+    // performed, and (b) segment start times are not aligned across variants, it's possible that
+    // the adjusted position may not be at a sync point when it was intended to be. However, this is
+    // very much an edge case, and getting it wrong is worth it for getting the vast majority of
+    // cases right whilst keeping the implementation relatively simple.
+    long startOfPlaylistInPeriodUs =
+        mediaPlaylist.startTimeUs - playlistTracker.getInitialStartTimeUs();
+    long relativePositionUs = positionUs - startOfPlaylistInPeriodUs;
+    int segmentIndex =
+        Util.binarySearchFloor(
+            mediaPlaylist.segments,
+            relativePositionUs,
+            /* inclusive= */ true,
+            /* stayInBounds= */ true);
+    long firstSyncUs = mediaPlaylist.segments.get(segmentIndex).relativeStartTimeUs;
+    long secondSyncUs = firstSyncUs;
+    if (segmentIndex != mediaPlaylist.segments.size() - 1) {
+      secondSyncUs = mediaPlaylist.segments.get(segmentIndex + 1).relativeStartTimeUs;
+    }
+    return seekParameters.resolveSeekPositionUs(relativePositionUs, firstSyncUs, secondSyncUs)
+        + startOfPlaylistInPeriodUs;
+  }
+
   /**
    * Returns the publication state of the given chunk.
    *

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaPeriod.java

@@ -421,7 +421,14 @@ public final class HlsMediaPeriod
 
   @Override
   public long getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) {
-    return positionUs;
+    long seekTargetUs = positionUs;
+    for (HlsSampleStreamWrapper sampleStreamWrapper : enabledSampleStreamWrappers) {
+      if (sampleStreamWrapper.isVideoSampleStream()) {
+        seekTargetUs = sampleStreamWrapper.getAdjustedSeekPositionUs(positionUs, seekParameters);
+        break;
+      }
+    }
+    return seekTargetUs;
   }
 
   // HlsSampleStreamWrapper.Callback implementation.

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsSampleStreamWrapper.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.FormatHolder;
 import com.google.android.exoplayer2.ParserException;
+import com.google.android.exoplayer2.SeekParameters;
 import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
 import com.google.android.exoplayer2.drm.DrmInitData;
 import com.google.android.exoplayer2.drm.DrmSession;
@@ -584,6 +585,22 @@ import org.checkerframework.checker.nullness.qual.RequiresNonNull;
         && exclusionDurationMs != C.TIME_UNSET;
   }
 
+  /** Returns whether the primary sample stream is {@link C#TRACK_TYPE_VIDEO}. */
+  public boolean isVideoSampleStream() {
+    return primarySampleQueueType == C.TRACK_TYPE_VIDEO;
+  }
+
+  /**
+   * Adjusts a seek position given the specified {@link SeekParameters}.
+   *
+   * @param positionUs The seek position in microseconds.
+   * @param seekParameters Parameters that control how the seek is performed.
+   * @return The adjusted seek position, in microseconds.
+   */
+  public long getAdjustedSeekPositionUs(long positionUs, SeekParameters seekParameters) {
+    return chunkSource.getAdjustedSeekPositionUs(positionUs, seekParameters);
+  }
+
   // SampleStream implementation.
 
   public boolean isReady(int sampleQueueIndex) {

library/hls/src/test/java/com/google/android/exoplayer2/source/hls/HlsChunkSourceTest.java

@@ -0,0 +1,183 @@
+/*
+ * Copyright 2021 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.exoplayer2.source.hls;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.when;
+
+import android.net.Uri;
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.SeekParameters;
+import com.google.android.exoplayer2.analytics.PlayerId;
+import com.google.android.exoplayer2.source.hls.playlist.HlsMediaPlaylist;
+import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistParser;
+import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistTracker;
+import com.google.android.exoplayer2.testutil.ExoPlayerTestRunner;
+import com.google.android.exoplayer2.testutil.FakeDataSource;
+import com.google.android.exoplayer2.testutil.TestUtil;
+import java.io.IOException;
+import java.io.InputStream;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+
+/** Unit tests for {@link HlsChunkSource}. */
+@RunWith(AndroidJUnit4.class)
+public class HlsChunkSourceTest {
+
+  private static final String PLAYLIST = "media/m3u8/media_playlist";
+  private static final String PLAYLIST_INDEPENDENT_SEGMENTS =
+      "media/m3u8/media_playlist_independent_segments";
+  private static final String PLAYLIST_EMPTY = "media/m3u8/media_playlist_empty";
+  private static final Uri PLAYLIST_URI = Uri.parse("http://example.com/");
+  private static final long PLAYLIST_START_PERIOD_OFFSET_US = 8_000_000L;
+
+  private final HlsExtractorFactory mockExtractorFactory = HlsExtractorFactory.DEFAULT;
+
+  @Mock private HlsPlaylistTracker mockPlaylistTracker;
+  private HlsChunkSource testChunkSource;
+
+  @Before
+  public void setup() throws IOException {
+    mockPlaylistTracker = Mockito.mock(HlsPlaylistTracker.class);
+
+    InputStream inputStream =
+        TestUtil.getInputStream(
+            ApplicationProvider.getApplicationContext(), PLAYLIST_INDEPENDENT_SEGMENTS);
+    HlsMediaPlaylist playlist =
+        (HlsMediaPlaylist) new HlsPlaylistParser().parse(PLAYLIST_URI, inputStream);
+    when(mockPlaylistTracker.getPlaylistSnapshot(eq(PLAYLIST_URI), anyBoolean()))
+        .thenReturn(playlist);
+
+    testChunkSource =
+        new HlsChunkSource(
+            mockExtractorFactory,
+            mockPlaylistTracker,
+            new Uri[] {PLAYLIST_URI},
+            new Format[] {ExoPlayerTestRunner.VIDEO_FORMAT},
+            new DefaultHlsDataSourceFactory(new FakeDataSource.Factory()),
+            /* mediaTransferListener= */ null,
+            new TimestampAdjusterProvider(),
+            /* muxedCaptionFormats= */ null,
+            PlayerId.UNSET);
+
+    when(mockPlaylistTracker.isSnapshotValid(eq(PLAYLIST_URI))).thenReturn(true);
+    // Mock that segments totalling PLAYLIST_START_PERIOD_OFFSET_US in duration have been removed
+    // from the start of the playlist.
+    when(mockPlaylistTracker.getInitialStartTimeUs())
+        .thenReturn(playlist.startTimeUs - PLAYLIST_START_PERIOD_OFFSET_US);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_previousSync() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(17_000_000), SeekParameters.PREVIOUS_SYNC);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(16_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_nextSync() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(17_000_000), SeekParameters.NEXT_SYNC);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(20_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_nextSyncAtEnd() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(24_000_000), SeekParameters.NEXT_SYNC);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(24_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_closestSyncBefore() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(17_000_000), SeekParameters.CLOSEST_SYNC);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(16_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_closestSyncAfter() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(19_000_000), SeekParameters.CLOSEST_SYNC);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(20_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_exact() {
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(17_000_000), SeekParameters.EXACT);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(17_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_noIndependentSegments() throws IOException {
+    InputStream inputStream =
+        TestUtil.getInputStream(ApplicationProvider.getApplicationContext(), PLAYLIST);
+    HlsMediaPlaylist playlist =
+        (HlsMediaPlaylist) new HlsPlaylistParser().parse(PLAYLIST_URI, inputStream);
+    when(mockPlaylistTracker.getPlaylistSnapshot(eq(PLAYLIST_URI), anyBoolean()))
+        .thenReturn(playlist);
+
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(100_000_000), SeekParameters.EXACT);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(100_000_000);
+  }
+
+  @Test
+  public void getAdjustedSeekPositionUs_emptyPlaylist() throws IOException {
+    InputStream inputStream =
+        TestUtil.getInputStream(ApplicationProvider.getApplicationContext(), PLAYLIST_EMPTY);
+    HlsMediaPlaylist playlist =
+        (HlsMediaPlaylist) new HlsPlaylistParser().parse(PLAYLIST_URI, inputStream);
+    when(mockPlaylistTracker.getPlaylistSnapshot(eq(PLAYLIST_URI), anyBoolean()))
+        .thenReturn(playlist);
+
+    long adjustedPositionUs =
+        testChunkSource.getAdjustedSeekPositionUs(
+            playlistTimeToPeriodTimeUs(100_000_000), SeekParameters.EXACT);
+
+    assertThat(periodTimeToPlaylistTimeUs(adjustedPositionUs)).isEqualTo(100_000_000);
+  }
+
+  private static long playlistTimeToPeriodTimeUs(long playlistTimeUs) {
+    return playlistTimeUs + PLAYLIST_START_PERIOD_OFFSET_US;
+  }
+
+  private static long periodTimeToPlaylistTimeUs(long periodTimeUs) {
+    return periodTimeUs - PLAYLIST_START_PERIOD_OFFSET_US;
+  }
+}

testdata/src/test/assets/media/m3u8/media_playlist

@@ -0,0 +1,16 @@
+#EXTM3U
+#EXT-X-MEDIA-SEQUENCE:2
+#EXT-X-MAP:URI="init.mp4"
+#EXTINF:4,
+2.mp4
+#EXTINF:4,
+3.mp4
+#EXTINF:4,
+4.mp4
+#EXTINF:4,
+5.mp4
+#EXTINF:4,
+6.mp4
+#EXTINF:4,
+7.mp4
+#EXT-X-ENDLIST

testdata/src/test/assets/media/m3u8/media_playlist_empty

@@ -0,0 +1,3 @@
+#EXTM3U
+#EXT-X-MEDIA-SEQUENCE:2
+#EXT-X-MAP:URI="init.mp4"

testdata/src/test/assets/media/m3u8/media_playlist_independent_segments

@@ -0,0 +1,17 @@
+#EXTM3U
+#EXT-X-MEDIA-SEQUENCE:2
+#EXT-X-INDEPENDENT-SEGMENTS
+#EXT-X-MAP:URI="init.mp4"
+#EXTINF:4,
+2.mp4
+#EXTINF:4,
+3.mp4
+#EXTINF:4,
+4.mp4
+#EXTINF:4,
+5.mp4
+#EXTINF:4,
+6.mp4
+#EXTINF:4,
+7.mp4
+#EXT-X-ENDLIST

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeDataSource.java

@@ -32,7 +32,6 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
 import java.util.ArrayList;
-import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
  * A fake {@link DataSource} capable of simulating various scenarios. It uses a {@link FakeDataSet}
@@ -43,9 +42,13 @@ public class FakeDataSource extends BaseDataSource {
   /** Factory to create a {@link FakeDataSource}. */
   public static class Factory implements DataSource.Factory {
 
-    protected @MonotonicNonNull FakeDataSet fakeDataSet;
+    protected FakeDataSet fakeDataSet;
     protected boolean isNetwork;
 
+    public Factory() {
+      fakeDataSet = new FakeDataSet();
+    }
+
     public final Factory setFakeDataSet(FakeDataSet fakeDataSet) {
       this.fakeDataSet = fakeDataSet;
       return this;
@@ -58,7 +61,7 @@ public class FakeDataSource extends BaseDataSource {
 
     @Override
     public FakeDataSource createDataSource() {
-      return new FakeDataSource(Assertions.checkStateNotNull(fakeDataSet), isNetwork);
+      return new FakeDataSource(fakeDataSet, isNetwork);
     }
   }