Support multiple audio tracks in HLS.

Issue: google#73
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=116808947

demo/src/main/java/com/google/android/exoplayer/demo/player/HlsRendererBuilder.java

@@ -20,6 +20,7 @@
 import com.google.android.exoplayer.MediaCodecAudioTrackRenderer;
 import com.google.android.exoplayer.MediaCodecSelector;
 import com.google.android.exoplayer.MediaCodecVideoTrackRenderer;
+import com.google.android.exoplayer.SampleSource;
 import com.google.android.exoplayer.TrackRenderer;
 import com.google.android.exoplayer.audio.AudioCapabilities;
 import com.google.android.exoplayer.demo.player.DemoPlayer.RendererBuilder;
@@ -56,7 +57,8 @@
 public class HlsRendererBuilder implements RendererBuilder {
 
   private static final int BUFFER_SEGMENT_SIZE = 64 * 1024;
-  private static final int MAIN_BUFFER_SEGMENTS = 256;
+  private static final int MAIN_BUFFER_SEGMENTS = 254;
+  private static final int AUDIO_BUFFER_SEGMENTS = 54;
   private static final int TEXT_BUFFER_SEGMENTS = 2;
 
   private final Context context;
@@ -133,7 +135,15 @@ public void onSingleManifest(HlsPlaylist manifest) {
       DefaultBandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
       PtsTimestampAdjusterProvider timestampAdjusterProvider = new PtsTimestampAdjusterProvider();
 
-      // Build the video/audio/metadata renderers.
+      boolean haveSubtitles = false;
+      boolean haveAudios = false;
+      if (manifest instanceof HlsMasterPlaylist) {
+        HlsMasterPlaylist masterPlaylist = (HlsMasterPlaylist) manifest;
+        haveSubtitles = !masterPlaylist.subtitles.isEmpty();
+        haveAudios = !masterPlaylist.audios.isEmpty();
+      }
+
+      // Build the video/id3 renderers.
       DataSource dataSource = new DefaultUriDataSource(context, bandwidthMeter, userAgent);
       HlsChunkSource chunkSource = new HlsChunkSource(true /* isMaster */, dataSource, url,
           manifest, DefaultHlsTrackSelector.newDefaultInstance(context), bandwidthMeter,
@@ -143,22 +153,34 @@ public void onSingleManifest(HlsPlaylist manifest) {
       MediaCodecVideoTrackRenderer videoRenderer = new MediaCodecVideoTrackRenderer(context,
           sampleSource, MediaCodecSelector.DEFAULT, MediaCodec.VIDEO_SCALING_MODE_SCALE_TO_FIT,
           5000, mainHandler, player, 50);
-      MediaCodecAudioTrackRenderer audioRenderer = new MediaCodecAudioTrackRenderer(sampleSource,
-          MediaCodecSelector.DEFAULT, null, true, player.getMainHandler(), player,
-          AudioCapabilities.getCapabilities(context), AudioManager.STREAM_MUSIC);
       MetadataTrackRenderer<List<Id3Frame>> id3Renderer = new MetadataTrackRenderer<>(
           sampleSource, new Id3Parser(), player, mainHandler.getLooper());
 
-      // Build the text renderer, preferring Webvtt where available.
-      boolean preferWebvtt = false;
-      if (manifest instanceof HlsMasterPlaylist) {
-        preferWebvtt = !((HlsMasterPlaylist) manifest).subtitles.isEmpty();
+      // Build the audio renderer.
+      MediaCodecAudioTrackRenderer audioRenderer;
+      if (haveAudios) {
+        DataSource audioDataSource = new DefaultUriDataSource(context, bandwidthMeter, userAgent);
+        HlsChunkSource audioChunkSource = new HlsChunkSource(false /* isMaster */, audioDataSource,
+            url, manifest, DefaultHlsTrackSelector.newAudioInstance(), bandwidthMeter,
+            timestampAdjusterProvider, HlsChunkSource.ADAPTIVE_MODE_SPLICE);
+        HlsSampleSource audioSampleSource = new HlsSampleSource(audioChunkSource, loadControl,
+            AUDIO_BUFFER_SEGMENTS * BUFFER_SEGMENT_SIZE, mainHandler, player, DemoPlayer.TYPE_TEXT);
+        audioRenderer = new MediaCodecAudioTrackRenderer(
+            new SampleSource[] {sampleSource, audioSampleSource}, MediaCodecSelector.DEFAULT, null,
+            true, player.getMainHandler(), player, AudioCapabilities.getCapabilities(context),
+            AudioManager.STREAM_MUSIC);
+      } else {
+        audioRenderer = new MediaCodecAudioTrackRenderer(sampleSource,
+            MediaCodecSelector.DEFAULT, null, true, player.getMainHandler(), player,
+            AudioCapabilities.getCapabilities(context), AudioManager.STREAM_MUSIC);
       }
+
+      // Build the text renderer.
       TrackRenderer textRenderer;
-      if (preferWebvtt) {
+      if (haveSubtitles) {
         DataSource textDataSource = new DefaultUriDataSource(context, bandwidthMeter, userAgent);
         HlsChunkSource textChunkSource = new HlsChunkSource(false /* isMaster */, textDataSource,
-            url, manifest, DefaultHlsTrackSelector.newVttInstance(), bandwidthMeter,
+            url, manifest, DefaultHlsTrackSelector.newSubtitleInstance(), bandwidthMeter,
             timestampAdjusterProvider, HlsChunkSource.ADAPTIVE_MODE_SPLICE);
         HlsSampleSource textSampleSource = new HlsSampleSource(textChunkSource, loadControl,
             TEXT_BUFFER_SEGMENTS * BUFFER_SEGMENT_SIZE, mainHandler, player, DemoPlayer.TYPE_TEXT);

library/src/main/java/com/google/android/exoplayer/MediaCodecAudioTrackRenderer.java

@@ -176,7 +176,32 @@ public MediaCodecAudioTrackRenderer(SampleSource source, MediaCodecSelector medi
       DrmSessionManager drmSessionManager, boolean playClearSamplesWithoutKeys,
       Handler eventHandler, EventListener eventListener, AudioCapabilities audioCapabilities,
       int streamType) {
-    super(source, mediaCodecSelector, drmSessionManager, playClearSamplesWithoutKeys, eventHandler,
+    this (new SampleSource[] {source}, mediaCodecSelector, drmSessionManager,
+        playClearSamplesWithoutKeys, eventHandler, eventListener, audioCapabilities, streamType);
+  }
+
+  /**
+   * @param sources The upstream sources from which the renderer obtains samples.
+   * @param mediaCodecSelector A decoder selector.
+   * @param drmSessionManager For use with encrypted content. May be null if support for encrypted
+   *     content is not required.
+   * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
+   *     For example a media file may start with a short clear region so as to allow playback to
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
+   *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
+   *     has obtained the keys necessary to decrypt encrypted regions of the media.
+   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
+   *     null if delivery of events is not required.
+   * @param eventListener A listener of events. May be null if delivery of events is not required.
+   * @param audioCapabilities The audio capabilities for playback on this device. May be null if the
+   *     default capabilities (no encoded audio passthrough support) should be assumed.
+   * @param streamType The type of audio stream for the {@link AudioTrack}.
+   */
+  public MediaCodecAudioTrackRenderer(SampleSource[] sources, MediaCodecSelector mediaCodecSelector,
+      DrmSessionManager drmSessionManager, boolean playClearSamplesWithoutKeys,
+      Handler eventHandler, EventListener eventListener, AudioCapabilities audioCapabilities,
+      int streamType) {
+    super(sources, mediaCodecSelector, drmSessionManager, playClearSamplesWithoutKeys, eventHandler,
         eventListener);
     this.eventListener = eventListener;
     this.audioSessionId = AudioTrack.SESSION_ID_NOT_SET;

library/src/main/java/com/google/android/exoplayer/MediaCodecTrackRenderer.java

@@ -250,7 +250,28 @@ private static String buildCustomDiagnosticInfo(int errorCode) {
   public MediaCodecTrackRenderer(SampleSource source, MediaCodecSelector mediaCodecSelector,
       DrmSessionManager drmSessionManager, boolean playClearSamplesWithoutKeys,
       Handler eventHandler, EventListener eventListener) {
-    super(source);
+    this (new SampleSource[] {source}, mediaCodecSelector, drmSessionManager,
+        playClearSamplesWithoutKeys, eventHandler, eventListener);
+  }
+
+  /**
+   * @param sources The upstream sources from which the renderer obtains samples.
+   * @param mediaCodecSelector A decoder selector.
+   * @param drmSessionManager For use with encrypted media. May be null if support for encrypted
+   *     media is not required.
+   * @param playClearSamplesWithoutKeys Encrypted media may contain clear (un-encrypted) regions.
+   *     For example a media file may start with a short clear region so as to allow playback to
+   *     begin in parallel with key acquisition. This parameter specifies whether the renderer is
+   *     permitted to play clear regions of encrypted media files before {@code drmSessionManager}
+   *     has obtained the keys necessary to decrypt encrypted regions of the media.
+   * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
+   *     null if delivery of events is not required.
+   * @param eventListener A listener of events. May be null if delivery of events is not required.
+   */
+  public MediaCodecTrackRenderer(SampleSource[] sources, MediaCodecSelector mediaCodecSelector,
+      DrmSessionManager drmSessionManager, boolean playClearSamplesWithoutKeys,
+      Handler eventHandler, EventListener eventListener) {
+    super(sources);
     Assertions.checkState(Util.SDK_INT >= 16);
     this.mediaCodecSelector = Assertions.checkNotNull(mediaCodecSelector);
     this.drmSessionManager = drmSessionManager;

library/src/main/java/com/google/android/exoplayer/MediaFormat.java

@@ -249,6 +249,13 @@ public MediaFormat copyWithDurationUs(long durationUs) {
         encoderPadding);
   }
 
+  public MediaFormat copyWithLanguage(String language) {
+    return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,
+        rotationDegrees, pixelWidthHeightRatio, channelCount, sampleRate, language,
+        subsampleOffsetUs, initializationData, adaptive, maxWidth, maxHeight, encoderDelay,
+        encoderPadding);
+  }
+
   public MediaFormat copyWithFixedTrackInfo(String trackId, int bitrate, int width, int height,
       String language) {
     return new MediaFormat(trackId, mimeType, bitrate, maxInputSize, durationUs, width, height,

library/src/main/java/com/google/android/exoplayer/hls/DefaultHlsTrackSelector.java

@@ -30,7 +30,8 @@
 public final class DefaultHlsTrackSelector implements HlsTrackSelector {
 
   private static final int TYPE_DEFAULT = 0;
-  private static final int TYPE_VTT = 1;
+  private static final int TYPE_AUDIO = 1;
+  private static final int TYPE_SUBTITLE = 2;
 
   private final Context context;
   private final int type;
@@ -45,13 +46,22 @@ public static DefaultHlsTrackSelector newDefaultInstance(Context context) {
     return new DefaultHlsTrackSelector(context, TYPE_DEFAULT);
   }
 
+  /**
+   * Creates a {@link DefaultHlsTrackSelector} that selects alternate audio renditions.
+   *
+   * @return The selector instance.
+   */
+  public static DefaultHlsTrackSelector newAudioInstance() {
+    return new DefaultHlsTrackSelector(null, TYPE_AUDIO);
+  }
+
   /**
    * Creates a {@link DefaultHlsTrackSelector} that selects subtitle renditions.
    *
    * @return The selector instance.
    */
-  public static DefaultHlsTrackSelector newVttInstance() {
-    return new DefaultHlsTrackSelector(null, TYPE_VTT);
+  public static DefaultHlsTrackSelector newSubtitleInstance() {
+    return new DefaultHlsTrackSelector(null, TYPE_SUBTITLE);
   }
 
   private DefaultHlsTrackSelector(Context context, int type) {
@@ -61,11 +71,11 @@ private DefaultHlsTrackSelector(Context context, int type) {
 
   @Override
   public void selectTracks(HlsMasterPlaylist playlist, Output output) throws IOException {
-    if (type == TYPE_VTT) {
-      List<Variant> subtitleVariants = playlist.subtitles;
-      if (subtitleVariants != null && !subtitleVariants.isEmpty()) {
-        for (int i = 0; i < subtitleVariants.size(); i++) {
-          output.fixedTrack(playlist, subtitleVariants.get(i));
+    if (type == TYPE_AUDIO || type == TYPE_SUBTITLE) {
+      List<Variant> variants = type == TYPE_AUDIO ? playlist.audios : playlist.subtitles;
+      if (variants != null && !variants.isEmpty()) {
+        for (int i = 0; i < variants.size(); i++) {
+          output.fixedTrack(playlist, variants.get(i));
         }
       }
       return;

library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java

@@ -227,7 +227,7 @@ public HlsChunkSource(boolean isMaster, DataSource dataSource, String playlistUr
       List<Variant> variants = new ArrayList<>();
       variants.add(new Variant(playlistUrl, format));
       masterPlaylist = new HlsMasterPlaylist(playlistUrl, variants,
-          Collections.<Variant>emptyList());
+          Collections.<Variant>emptyList(), Collections.<Variant>emptyList(), null, null);
     }
   }
 
@@ -308,6 +308,23 @@ public Variant getFixedTrackVariant(int index) {
     return variants.length == 1 ? variants[0] : null;
   }
 
+  /**
+   * Returns the language of the audio muxed into variants, or null if unknown.
+   *
+   * @return The language of the audio muxed into variants, or null if unknown.
+   */
+  public String getMuxedAudioLanguage() {
+    return masterPlaylist.muxedAudioLanguage;
+  }
+
+  /**
+   * Returns the language of the captions muxed into variants, or null if unknown.
+   *
+   * @return The language of the captions muxed into variants, or null if unknown.
+   */
+  public String getMuxedCaptionLanguage() {
+    return masterPlaylist.muxedCaptionLanguage;
+  }
 
   /**
    * Returns the currently selected track index.

library/src/main/java/com/google/android/exoplayer/hls/HlsMasterPlaylist.java

@@ -24,12 +24,21 @@
 public final class HlsMasterPlaylist extends HlsPlaylist {
 
   public final List<Variant> variants;
+  public final List<Variant> audios;
   public final List<Variant> subtitles;
 
-  public HlsMasterPlaylist(String baseUri, List<Variant> variants, List<Variant> subtitles) {
+  public final String muxedAudioLanguage;
+  public final String muxedCaptionLanguage;
+
+  public HlsMasterPlaylist(String baseUri, List<Variant> variants,
+      List<Variant> audios, List<Variant> subtitles, String muxedAudioLanguage,
+      String muxedCaptionLanguage) {
     super(baseUri, HlsPlaylist.TYPE_MASTER);
     this.variants = Collections.unmodifiableList(variants);
+    this.audios = Collections.unmodifiableList(audios);
     this.subtitles = Collections.unmodifiableList(subtitles);
+    this.muxedAudioLanguage = muxedAudioLanguage;
+    this.muxedCaptionLanguage = muxedCaptionLanguage;
   }
 
 }

library/src/main/java/com/google/android/exoplayer/hls/HlsPlaylistParser.java

@@ -59,6 +59,7 @@ public final class HlsPlaylistParser implements UriLoadable.Parser<HlsPlaylist>
   private static final String METHOD_ATTR = "METHOD";
   private static final String URI_ATTR = "URI";
   private static final String IV_ATTR = "IV";
+  private static final String INSTREAM_ID_ATTR = "INSTREAM-ID";
 
   private static final String AUDIO_TYPE = "AUDIO";
   private static final String VIDEO_TYPE = "VIDEO";
@@ -98,6 +99,8 @@ public final class HlsPlaylistParser implements UriLoadable.Parser<HlsPlaylist>
       Pattern.compile(LANGUAGE_ATTR + "=\"(.+?)\"");
   private static final Pattern NAME_ATTR_REGEX =
       Pattern.compile(NAME_ATTR + "=\"(.+?)\"");
+  private static final Pattern INSTREAM_ID_ATTR_REGEX =
+      Pattern.compile(INSTREAM_ID_ATTR + "=\"(.+?)\"");
   // private static final Pattern AUTOSELECT_ATTR_REGEX =
   //     HlsParserUtil.compileBooleanAttrPattern(AUTOSELECT_ATTR);
   // private static final Pattern DEFAULT_ATTR_REGEX =
@@ -140,29 +143,48 @@ public HlsPlaylist parse(String connectionUrl, InputStream inputStream)
   private static HlsMasterPlaylist parseMasterPlaylist(LineIterator iterator, String baseUri)
       throws IOException {
     ArrayList<Variant> variants = new ArrayList<>();
+    ArrayList<Variant> audios = new ArrayList<>();
     ArrayList<Variant> subtitles = new ArrayList<>();
     int bitrate = 0;
     String codecs = null;
     int width = -1;
     int height = -1;
     String name = null;
+    String muxedAudioLanguage = null;
+    String muxedCaptionLanguage = null;
 
     boolean expectingStreamInfUrl = false;
     String line;
     while (iterator.hasNext()) {
       line = iterator.next();
       if (line.startsWith(MEDIA_TAG)) {
         String type = HlsParserUtil.parseStringAttr(line, TYPE_ATTR_REGEX, TYPE_ATTR);
-        if (SUBTITLES_TYPE.equals(type)) {
+        if (CLOSED_CAPTIONS_TYPE.equals(type)) {
+          String instreamId = HlsParserUtil.parseStringAttr(line, INSTREAM_ID_ATTR_REGEX,
+              INSTREAM_ID_ATTR);
+          if ("CC1".equals(instreamId)) {
+            muxedCaptionLanguage = HlsParserUtil.parseOptionalStringAttr(line, LANGUAGE_ATTR_REGEX);
+          }
+        } else if (SUBTITLES_TYPE.equals(type)) {
           // We assume all subtitles belong to the same group.
           String subtitleName = HlsParserUtil.parseStringAttr(line, NAME_ATTR_REGEX, NAME_ATTR);
           String uri = HlsParserUtil.parseStringAttr(line, URI_ATTR_REGEX, URI_ATTR);
           String language = HlsParserUtil.parseOptionalStringAttr(line, LANGUAGE_ATTR_REGEX);
           Format format = new Format(subtitleName, MimeTypes.APPLICATION_M3U8, -1, -1, -1, -1, -1,
               -1, language, codecs);
           subtitles.add(new Variant(uri, format));
-        } else {
-          // TODO: Support other types of media tag.
+        } else if (AUDIO_TYPE.equals(type)) {
+          // We assume all audios belong to the same group.
+          String language = HlsParserUtil.parseOptionalStringAttr(line, LANGUAGE_ATTR_REGEX);
+          String uri = HlsParserUtil.parseOptionalStringAttr(line, URI_ATTR_REGEX);
+          if (uri != null) {
+            String audioName = HlsParserUtil.parseStringAttr(line, NAME_ATTR_REGEX, NAME_ATTR);
+            Format format = new Format(audioName, MimeTypes.APPLICATION_M3U8, -1, -1, -1, -1, -1,
+                -1, language, codecs);
+            audios.add(new Variant(uri, format));
+          } else {
+            muxedAudioLanguage = language;
+          }
         }
       } else if (line.startsWith(STREAM_INF_TAG)) {
         bitrate = HlsParserUtil.parseIntAttr(line, BANDWIDTH_ATTR_REGEX, BANDWIDTH_ATTR);
@@ -202,7 +224,8 @@ private static HlsMasterPlaylist parseMasterPlaylist(LineIterator iterator, Stri
         expectingStreamInfUrl = false;
       }
     }
-    return new HlsMasterPlaylist(baseUri, variants, subtitles);
+    return new HlsMasterPlaylist(baseUri, variants, audios, subtitles, muxedAudioLanguage,
+        muxedCaptionLanguage);
   }
 
   private static HlsMediaPlaylist parseMediaPlaylist(LineIterator iterator, String baseUri)