Add #EXT-X-PROGRAM-DATE-TIME support for HLS media playlists

Issue:#747

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=140525595

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

@@ -212,7 +212,8 @@ public void getNextChunk(HlsMediaChunk previous, long playbackPositionUs, HlsChu
         // If the playlist is too old to contain the chunk, we need to refresh it.
         chunkMediaSequence = mediaPlaylist.mediaSequence + mediaPlaylist.segments.size();
       } else {
-        chunkMediaSequence = Util.binarySearchFloor(mediaPlaylist.segments, targetPositionUs, true,
+        chunkMediaSequence = Util.binarySearchFloor(mediaPlaylist.segments,
+            targetPositionUs - mediaPlaylist.startTimeUs, true,
             !playlistTracker.isLive() || previous == null) + mediaPlaylist.mediaSequence;
         if (chunkMediaSequence < mediaPlaylist.mediaSequence && previous != null) {
           // We try getting the next chunk without adapting in case that's the reason for falling
@@ -259,16 +260,6 @@ public void getNextChunk(HlsMediaChunk previous, long playbackPositionUs, HlsChu
       clearEncryptionData();
     }
 
-    // Compute start time and sequence number of the next chunk.
-    long startTimeUs = segment.startTimeUs;
-    if (previous != null && !switchingVariant) {
-      startTimeUs = previous.getAdjustedEndTimeUs();
-    }
-    Uri chunkUri = UriUtil.resolveToUri(mediaPlaylist.baseUri, segment.url);
-
-    TimestampAdjuster timestampAdjuster = timestampAdjusterProvider.getAdjuster(
-        segment.discontinuitySequenceNumber, startTimeUs);
-
     DataSpec initDataSpec = null;
     Segment initSegment = mediaPlaylist.initializationSegment;
     if (initSegment != null) {
@@ -277,13 +268,20 @@ public void getNextChunk(HlsMediaChunk previous, long playbackPositionUs, HlsChu
           initSegment.byterangeLength, null);
     }
 
+    // Compute start time of the next chunk.
+    long startTimeUs = mediaPlaylist.startTimeUs + segment.relativeStartTimeUs;
+    TimestampAdjuster timestampAdjuster = timestampAdjusterProvider.getAdjuster(
+        segment.discontinuitySequenceNumber, startTimeUs);
+
     // Configure the data source and spec for the chunk.
+    Uri chunkUri = UriUtil.resolveToUri(mediaPlaylist.baseUri, segment.url);
     DataSpec dataSpec = new DataSpec(chunkUri, segment.byterangeOffset, segment.byterangeLength,
         null);
     out.chunk = new HlsMediaChunk(dataSource, dataSpec, initDataSpec, variants[newVariantIndex],
-        trackSelection.getSelectionReason(), trackSelection.getSelectionData(), segment,
-        chunkMediaSequence, isTimestampMaster, timestampAdjuster, previous, encryptionKey,
-        encryptionIv);
+        trackSelection.getSelectionReason(), trackSelection.getSelectionData(),
+        startTimeUs, startTimeUs + segment.durationUs, chunkMediaSequence,
+        segment.discontinuitySequenceNumber, isTimestampMaster, timestampAdjuster, previous,
+        encryptionKey, encryptionIv);
   }
 
   /**

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

@@ -28,7 +28,6 @@
 import com.google.android.exoplayer2.extractor.ts.TsExtractor;
 import com.google.android.exoplayer2.source.chunk.MediaChunk;
 import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUrl;
-import com.google.android.exoplayer2.source.hls.playlist.HlsMediaPlaylist.Segment;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.util.MimeTypes;
@@ -89,30 +88,32 @@
    * @param hlsUrl The url of the playlist from which this chunk was obtained.
    * @param trackSelectionReason See {@link #trackSelectionReason}.
    * @param trackSelectionData See {@link #trackSelectionData}.
-   * @param segment The {@link Segment} for which this media chunk is created.
+   * @param startTimeUs The start time of the chunk in microseconds.
+   * @param endTimeUs The end time of the chunk in microseconds.
    * @param chunkIndex The media sequence number of the chunk.
+   * @param discontinuitySequenceNumber The discontinuity sequence number of the chunk.
    * @param isMasterTimestampSource True if the chunk can initialize the timestamp adjuster.
    * @param timestampAdjuster Adjuster corresponding to the provided discontinuity sequence number.
    * @param previousChunk The {@link HlsMediaChunk} that preceded this one. May be null.
    * @param encryptionKey For AES encryption chunks, the encryption key.
    * @param encryptionIv For AES encryption chunks, the encryption initialization vector.
    */
   public HlsMediaChunk(DataSource dataSource, DataSpec dataSpec, DataSpec initDataSpec,
-      HlsUrl hlsUrl, int trackSelectionReason, Object trackSelectionData, Segment segment,
-      int chunkIndex, boolean isMasterTimestampSource, TimestampAdjuster timestampAdjuster,
+      HlsUrl hlsUrl, int trackSelectionReason, Object trackSelectionData, long startTimeUs,
+      long endTimeUs, int chunkIndex, int discontinuitySequenceNumber,
+      boolean isMasterTimestampSource, TimestampAdjuster timestampAdjuster,
       HlsMediaChunk previousChunk, byte[] encryptionKey, byte[] encryptionIv) {
     super(buildDataSource(dataSource, encryptionKey, encryptionIv), dataSpec, hlsUrl.format,
-        trackSelectionReason, trackSelectionData, segment.startTimeUs,
-        segment.startTimeUs + segment.durationUs, chunkIndex);
+        trackSelectionReason, trackSelectionData, startTimeUs, endTimeUs, chunkIndex);
     this.initDataSpec = initDataSpec;
     this.hlsUrl = hlsUrl;
     this.isMasterTimestampSource = isMasterTimestampSource;
     this.timestampAdjuster = timestampAdjuster;
+    this.discontinuitySequenceNumber = discontinuitySequenceNumber;
     this.previousChunk = previousChunk;
     // Note: this.dataSource and dataSource may be different.
     this.isEncrypted = this.dataSource instanceof Aes128DataSource;
     initDataSource = dataSource;
-    discontinuitySequenceNumber = segment.discontinuitySequenceNumber;
     adjustedEndTimeUs = endTimeUs;
     uid = UID_SOURCE.getAndIncrement();
   }
@@ -136,7 +137,7 @@ public long getAdjustedStartTimeUs() {
   }
 
   /**
-   * Returns the presentation time in microseconds of the last sample in the chunk
+   * Returns the presentation time in microseconds of the last sample in the chunk.
    */
   public long getAdjustedEndTimeUs() {
     return adjustedEndTimeUs;
@@ -231,8 +232,8 @@ private Extractor buildExtractor() {
   }
 
   private void maybeLoadInitData() throws IOException, InterruptedException {
-    if (previousChunk == null || previousChunk.extractor != extractor || initLoadCompleted
-        || initDataSpec == null) {
+    if ((previousChunk != null && previousChunk.extractor == extractor)
+        || initLoadCompleted || initDataSpec == null) {
       return;
     }
     DataSpec initSegmentDataSpec = Util.getRemainderDataSpec(initDataSpec, initSegmentBytesLoaded);

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

@@ -103,10 +103,10 @@ public void onPrimaryPlaylistRefreshed(HlsMediaPlaylist playlist) {
     SinglePeriodTimeline timeline;
     if (playlistTracker.isLive()) {
       // TODO: fix windowPositionInPeriodUs when playlist is empty.
-      long windowPositionInPeriodUs = playlist.getStartTimeUs();
+      long windowPositionInPeriodUs = playlist.startTimeUs;
       List<HlsMediaPlaylist.Segment> segments = playlist.segments;
       long windowDefaultStartPositionUs = segments.isEmpty() ? 0
-          : segments.get(Math.max(0, segments.size() - 3)).startTimeUs - windowPositionInPeriodUs;
+          : segments.get(Math.max(0, segments.size() - 3)).relativeStartTimeUs;
       timeline = new SinglePeriodTimeline(C.TIME_UNSET, playlist.durationUs,
           windowPositionInPeriodUs, windowDefaultStartPositionUs, true, !playlist.hasEndTag);
     } else /* not live */ {

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

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.source.hls.playlist;
 
 import com.google.android.exoplayer2.C;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
@@ -33,7 +32,7 @@ public static final class Segment implements Comparable<Long> {
     public final String url;
     public final long durationUs;
     public final int discontinuitySequenceNumber;
-    public final long startTimeUs;
+    public final long relativeStartTimeUs;
     public final boolean isEncrypted;
     public final String encryptionKeyUri;
     public final String encryptionIV;
@@ -45,12 +44,12 @@ public Segment(String uri, long byterangeOffset, long byterangeLength) {
     }
 
     public Segment(String uri, long durationUs, int discontinuitySequenceNumber,
-        long startTimeUs, boolean isEncrypted, String encryptionKeyUri, String encryptionIV,
+        long relativeStartTimeUs, boolean isEncrypted, String encryptionKeyUri, String encryptionIV,
         long byterangeOffset, long byterangeLength) {
       this.url = uri;
       this.durationUs = durationUs;
       this.discontinuitySequenceNumber = discontinuitySequenceNumber;
-      this.startTimeUs = startTimeUs;
+      this.relativeStartTimeUs = relativeStartTimeUs;
       this.isEncrypted = isEncrypted;
       this.encryptionKeyUri = encryptionKeyUri;
       this.encryptionIV = encryptionIV;
@@ -59,64 +58,55 @@ public Segment(String uri, long durationUs, int discontinuitySequenceNumber,
     }
 
     @Override
-    public int compareTo(Long startTimeUs) {
-      return this.startTimeUs > startTimeUs ? 1 : (this.startTimeUs < startTimeUs ? -1 : 0);
-    }
-
-    public Segment copyWithStartTimeUs(long startTimeUs) {
-      return new Segment(url, durationUs, discontinuitySequenceNumber, startTimeUs, isEncrypted,
-          encryptionKeyUri, encryptionIV, byterangeOffset, byterangeLength);
+    public int compareTo(Long relativeStartTimeUs) {
+      return this.relativeStartTimeUs > relativeStartTimeUs
+          ? 1 : (this.relativeStartTimeUs < relativeStartTimeUs ? -1 : 0);
     }
 
   }
 
+  public final long startTimeUs;
   public final int mediaSequence;
   public final int version;
   public final Segment initializationSegment;
   public final List<Segment> segments;
   public final boolean hasEndTag;
+  public final boolean hasProgramDateTime;
   public final long durationUs;
 
-  public HlsMediaPlaylist(String baseUri, int mediaSequence, int version,
-      boolean hasEndTag, Segment initializationSegment, List<Segment> segments) {
+  public HlsMediaPlaylist(String baseUri, long startTimeUs, int mediaSequence, int version,
+      boolean hasEndTag, boolean hasProgramDateTime, Segment initializationSegment,
+      List<Segment> segments) {
     super(baseUri, HlsPlaylist.TYPE_MEDIA);
+    this.startTimeUs = startTimeUs;
     this.mediaSequence = mediaSequence;
     this.version = version;
     this.hasEndTag = hasEndTag;
+    this.hasProgramDateTime = hasProgramDateTime;
     this.initializationSegment = initializationSegment;
     this.segments = Collections.unmodifiableList(segments);
 
     if (!segments.isEmpty()) {
-      Segment first = segments.get(0);
       Segment last = segments.get(segments.size() - 1);
-      durationUs = last.startTimeUs + last.durationUs - first.startTimeUs;
+      durationUs = last.relativeStartTimeUs + last.durationUs;
     } else {
       durationUs = 0;
     }
   }
 
-  public long getStartTimeUs() {
-    return segments.isEmpty() ? 0 : segments.get(0).startTimeUs;
+  public boolean isNewerThan(HlsMediaPlaylist other) {
+    return other == null || mediaSequence > other.mediaSequence
+        || (mediaSequence == other.mediaSequence && segments.size() > other.segments.size())
+        || (hasEndTag && !other.hasEndTag);
   }
 
   public long getEndTimeUs() {
-    return getStartTimeUs() + durationUs;
-  }
-
-  public HlsMediaPlaylist copyWithStartTimeUs(long newStartTimeUs) {
-    long startTimeOffsetUs = newStartTimeUs - getStartTimeUs();
-    int segmentsSize = segments.size();
-    List<Segment> newSegments = new ArrayList<>(segmentsSize);
-    for (int i = 0; i < segmentsSize; i++) {
-      Segment segment = segments.get(i);
-      newSegments.add(segment.copyWithStartTimeUs(segment.startTimeUs + startTimeOffsetUs));
-    }
-    return copyWithSegments(newSegments);
+    return startTimeUs + durationUs;
   }
 
-  public HlsMediaPlaylist copyWithSegments(List<Segment> segments) {
-    return new HlsMediaPlaylist(baseUri, mediaSequence, version, hasEndTag,
-        initializationSegment, segments);
+  public HlsMediaPlaylist copyWithStartTimeUs(long startTimeUs) {
+    return new HlsMediaPlaylist(baseUri, startTimeUs, mediaSequence, version, hasEndTag,
+        hasProgramDateTime, initializationSegment, segments);
   }
 
 }

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

@@ -22,6 +22,7 @@
 import com.google.android.exoplayer2.source.hls.playlist.HlsMediaPlaylist.Segment;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.Util;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
@@ -43,6 +44,7 @@ public final class HlsPlaylistParser implements ParsingLoadable.Parser<HlsPlayli
   private static final String TAG_MEDIA = "#EXT-X-MEDIA";
   private static final String TAG_DISCONTINUITY = "#EXT-X-DISCONTINUITY";
   private static final String TAG_DISCONTINUITY_SEQUENCE = "#EXT-X-DISCONTINUITY-SEQUENCE";
+  private static final String TAG_PROGRAM_DATE_TIME = "#EXT-X-PROGRAM-DATE-TIME";
   private static final String TAG_INIT_SEGMENT = "#EXT-X-MAP";
   private static final String TAG_MEDIA_DURATION = "#EXTINF";
   private static final String TAG_MEDIA_SEQUENCE = "#EXT-X-MEDIA-SEQUENCE";
@@ -62,17 +64,10 @@ public final class HlsPlaylistParser implements ParsingLoadable.Parser<HlsPlayli
   private static final String BOOLEAN_TRUE = "YES";
   private static final String BOOLEAN_FALSE = "NO";
 
-  private static final Pattern REGEX_GROUP_ID = Pattern.compile("GROUP-ID=\"(.+?)\"");
-  private static final Pattern REGEX_VIDEO = Pattern.compile("VIDEO=\"(.+?)\"");
-  private static final Pattern REGEX_AUDIO = Pattern.compile("AUDIO=\"(.+?)\"");
-  private static final Pattern REGEX_CLOSED_CAPTIONS = Pattern.compile("CLOSED-CAPTIONS=\"(.+?)\"");
-  private static final Pattern REGEX_SUBTITLES = Pattern.compile("SUBTITLES=\"(.+?)\"");
   private static final Pattern REGEX_BANDWIDTH = Pattern.compile("BANDWIDTH=(\\d+)\\b");
   private static final Pattern REGEX_CODECS = Pattern.compile("CODECS=\"(.+?)\"");
   private static final Pattern REGEX_RESOLUTION = Pattern.compile("RESOLUTION=(\\d+x\\d+)");
   private static final Pattern REGEX_VERSION = Pattern.compile(TAG_VERSION + ":(\\d+)\\b");
-  private static final Pattern REGEX_TARGET_DURATION = Pattern.compile(TAG_TARGET_DURATION
-      + ":(\\d+)\\b");
   private static final Pattern REGEX_MEDIA_SEQUENCE = Pattern.compile(TAG_MEDIA_SEQUENCE
       + ":(\\d+)\\b");
   private static final Pattern REGEX_MEDIA_DURATION = Pattern.compile(TAG_MEDIA_DURATION
@@ -211,14 +206,14 @@ private static int parseSelectionFlags(String line) {
   private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String baseUri)
       throws IOException {
     int mediaSequence = 0;
-    int targetDurationSecs = 0;
     int version = 1; // Default version == 1.
     boolean hasEndTag = false;
     Segment initializationSegment = null;
     List<Segment> segments = new ArrayList<>();
 
     long segmentDurationUs = 0;
     int discontinuitySequenceNumber = 0;
+    long playlistStartTimeUs = 0;
     long segmentStartTimeUs = 0;
     long segmentByteRangeOffset = 0;
     long segmentByteRangeLength = C.LENGTH_UNSET;
@@ -244,8 +239,6 @@ private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String
         initializationSegment = new Segment(uri, segmentByteRangeOffset, segmentByteRangeLength);
         segmentByteRangeOffset = 0;
         segmentByteRangeLength = C.LENGTH_UNSET;
-      } else if (line.startsWith(TAG_TARGET_DURATION)) {
-        targetDurationSecs = parseIntAttr(line, REGEX_TARGET_DURATION);
       } else if (line.startsWith(TAG_MEDIA_SEQUENCE)) {
         mediaSequence = parseIntAttr(line, REGEX_MEDIA_SEQUENCE);
         segmentMediaSequence = mediaSequence;
@@ -275,6 +268,12 @@ private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String
         discontinuitySequenceNumber = Integer.parseInt(line.substring(line.indexOf(':') + 1));
       } else if (line.equals(TAG_DISCONTINUITY)) {
         discontinuitySequenceNumber++;
+      } else if (line.startsWith(TAG_PROGRAM_DATE_TIME)) {
+        if (playlistStartTimeUs == 0) {
+          long programDatetimeUs =
+              C.msToUs(Util.parseXsDateTime(line.substring(line.indexOf(':') + 1)));
+          playlistStartTimeUs = programDatetimeUs - segmentStartTimeUs;
+        }
       } else if (!line.startsWith("#")) {
         String segmentEncryptionIV;
         if (!isEncrypted) {
@@ -301,8 +300,8 @@ private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String
         hasEndTag = true;
       }
     }
-    return new HlsMediaPlaylist(baseUri, mediaSequence, version, hasEndTag,
-        initializationSegment, segments);
+    return new HlsMediaPlaylist(baseUri, playlistStartTimeUs, mediaSequence, version, hasEndTag,
+        playlistStartTimeUs != 0, initializationSegment, segments);
   }
 
   private static String parseStringAttr(String line, Pattern pattern) throws ParserException {