Add some initial plumbing for DASH EMSG support

Issue: #2176

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=143554094

library/src/main/java/com/google/android/exoplayer2/source/dash/manifest/AdaptationSet.java

@@ -23,18 +23,48 @@
  */
 public class AdaptationSet {
 
-  public static final int UNSET_ID = -1;
+  /**
+   * Value of {@link #id} indicating no value is set.=
+   */
+  public static final int ID_UNSET = -1;
 
+  /**
+   * A non-negative identifier for the adaptation set that's unique in the scope of its containing
+   * period, or {@link #ID_UNSET} if not specified.
+   */
   public final int id;
 
+  /**
+   * The type of the adaptation set. One of the {@link com.google.android.exoplayer2.C}
+   * {@code TRACK_TYPE_*} constants.
+   */
   public final int type;
 
+  /**
+   * The {@link Representation}s in the adaptation set.
+   */
   public final List<Representation> representations;
 
-  public AdaptationSet(int id, int type, List<Representation> representations) {
+  /**
+   * The {@link InbandEventStream}s contained by all {@link Representation}s in the adaptation set.
+   */
+  public final List<InbandEventStream> inbandEventStreams;
+
+  /**
+   * @param id A non-negative identifier for the adaptation set that's unique in the scope of its
+   *     containing period, or {@link #ID_UNSET} if not specified.
+   * @param type The type of the adaptation set. One of the {@link com.google.android.exoplayer2.C}
+   *     {@code TRACK_TYPE_*} constants.
+   * @param representations The {@link Representation}s in the adaptation set.
+   * @param inbandEventStreams The {@link InbandEventStream}s contained by all
+   *     {@link Representation}s in the adaptation set.
+   */
+  public AdaptationSet(int id, int type, List<Representation> representations,
+      List<InbandEventStream> inbandEventStreams) {
     this.id = id;
     this.type = type;
     this.representations = Collections.unmodifiableList(representations);
+    this.inbandEventStreams = Collections.unmodifiableList(inbandEventStreams);
   }
 
 }

library/src/main/java/com/google/android/exoplayer2/source/dash/manifest/DashManifestParser.java

@@ -227,7 +227,7 @@ protected Period buildPeriod(String id, long startMs, List<AdaptationSet> adapta
 
   protected AdaptationSet parseAdaptationSet(XmlPullParser xpp, String baseUrl,
       SegmentBase segmentBase) throws XmlPullParserException, IOException {
-    int id = parseInt(xpp, "id", AdaptationSet.UNSET_ID);
+    int id = parseInt(xpp, "id", AdaptationSet.ID_UNSET);
     int contentType = parseContentType(xpp);
 
     String mimeType = xpp.getAttributeValue(null, "mimeType");
@@ -241,6 +241,8 @@ protected AdaptationSet parseAdaptationSet(XmlPullParser xpp, String baseUrl,
     int accessibilityChannel = Format.NO_VALUE;
     ArrayList<SchemeData> drmSchemeDatas = new ArrayList<>();
     List<RepresentationInfo> representationInfos = new ArrayList<>();
+    List<InbandEventStream> adaptationSetInbandEventStreams = new ArrayList<>();
+    List<InbandEventStream> commonRepresentationInbandEventStreams = null;
 
     boolean seenFirstBaseUrl = false;
     do {
@@ -265,6 +267,22 @@ protected AdaptationSet parseAdaptationSet(XmlPullParser xpp, String baseUrl,
         contentType = checkContentTypeConsistency(contentType,
             getContentType(representationInfo.format));
         representationInfos.add(representationInfo);
+        // Initialize or update InbandEventStream elements defined in all child Representations.
+        List<InbandEventStream> inbandEventStreams = representationInfo.inbandEventStreams;
+        if (commonRepresentationInbandEventStreams == null) {
+          // Initialize with the elements defined in this representation.
+          commonRepresentationInbandEventStreams = new ArrayList<>(inbandEventStreams);
+        } else {
+          // Remove elements that are not also defined in this representation.
+          for (int i = commonRepresentationInbandEventStreams.size() - 1; i >= 0; i--) {
+            InbandEventStream inbandEventStream = commonRepresentationInbandEventStreams.get(i);
+            if (!inbandEventStreams.contains(inbandEventStream)) {
+              Log.w(TAG, "Ignoring InbandEventStream element not defined on all Representations: "
+                  + inbandEventStream);
+              commonRepresentationInbandEventStreams.remove(i);
+            }
+          }
+        }
       } else if (XmlPullParserUtil.isStartTag(xpp, "AudioChannelConfiguration")) {
         audioChannels = parseAudioChannelConfiguration(xpp);
       } else if (XmlPullParserUtil.isStartTag(xpp, "Accessibility")) {
@@ -275,23 +293,34 @@ protected AdaptationSet parseAdaptationSet(XmlPullParser xpp, String baseUrl,
         segmentBase = parseSegmentList(xpp, (SegmentList) segmentBase);
       } else if (XmlPullParserUtil.isStartTag(xpp, "SegmentTemplate")) {
         segmentBase = parseSegmentTemplate(xpp, (SegmentTemplate) segmentBase);
+      } else if (XmlPullParserUtil.isStartTag(xpp, "InbandEventStream")) {
+        adaptationSetInbandEventStreams.add(parseInbandEventStream(xpp));
       } else if (XmlPullParserUtil.isStartTag(xpp)) {
         parseAdaptationSetChild(xpp);
       }
     } while (!XmlPullParserUtil.isEndTag(xpp, "AdaptationSet"));
 
+    // Pull up InbandEventStream elements defined in all child Representations.
+    for (int i = 0; i < commonRepresentationInbandEventStreams.size(); i++) {
+      InbandEventStream inbandEventStream = commonRepresentationInbandEventStreams.get(i);
+      if (!adaptationSetInbandEventStreams.contains(inbandEventStream)) {
+        adaptationSetInbandEventStreams.add(inbandEventStream);
+      }
+    }
+
+    // Build the representations.
     List<Representation> representations = new ArrayList<>(representationInfos.size());
     for (int i = 0; i < representationInfos.size(); i++) {
       representations.add(buildRepresentation(representationInfos.get(i), contentId,
           drmSchemeDatas));
     }
 
-    return buildAdaptationSet(id, contentType, representations);
+    return buildAdaptationSet(id, contentType, representations, adaptationSetInbandEventStreams);
   }
 
   protected AdaptationSet buildAdaptationSet(int id, int contentType,
-      List<Representation> representations) {
-    return new AdaptationSet(id, contentType, representations);
+      List<Representation> representations, List<InbandEventStream> inbandEventStreams) {
+    return new AdaptationSet(id, contentType, representations, inbandEventStreams);
   }
 
   protected int parseContentType(XmlPullParser xpp) {
@@ -355,6 +384,24 @@ protected SchemeData parseContentProtection(XmlPullParser xpp) throws XmlPullPar
     }
   }
 
+  /**
+   * Parses an InbandEventStream element.
+   *
+   * @param xpp The parser from which to read.
+   * @throws XmlPullParserException If an error occurs parsing the element.
+   * @throws IOException If an error occurs reading the element.
+   * @return {@link InbandEventStream} parsed from the element.
+   */
+  protected InbandEventStream parseInbandEventStream(XmlPullParser xpp)
+      throws XmlPullParserException, IOException {
+    String schemeIdUri = parseString(xpp, "schemeIdUri", null);
+    String value = parseString(xpp, "value", null);
+    do {
+      xpp.next();
+    } while (!XmlPullParserUtil.isEndTag(xpp, "InbandEventStream"));
+    return new InbandEventStream(schemeIdUri, value);
+  }
+
   /**
    * Parses children of AdaptationSet elements not specifically parsed elsewhere.
    *
@@ -386,6 +433,7 @@ protected RepresentationInfo parseRepresentation(XmlPullParser xpp, String baseU
     int audioChannels = adaptationSetAudioChannels;
     int audioSamplingRate = parseInt(xpp, "audioSamplingRate", adaptationSetAudioSamplingRate);
     ArrayList<SchemeData> drmSchemeDatas = new ArrayList<>();
+    ArrayList<InbandEventStream> inbandEventStreams = new ArrayList<>();
 
     boolean seenFirstBaseUrl = false;
     do {
@@ -408,6 +456,8 @@ protected RepresentationInfo parseRepresentation(XmlPullParser xpp, String baseU
         if (contentProtection != null) {
           drmSchemeDatas.add(contentProtection);
         }
+      } else if (XmlPullParserUtil.isStartTag(xpp, "InbandEventStream")) {
+        inbandEventStreams.add(parseInbandEventStream(xpp));
       }
     } while (!XmlPullParserUtil.isEndTag(xpp, "Representation"));
 
@@ -416,7 +466,7 @@ protected RepresentationInfo parseRepresentation(XmlPullParser xpp, String baseU
         codecs);
     segmentBase = segmentBase != null ? segmentBase : new SingleSegmentBase();
 
-    return new RepresentationInfo(format, baseUrl, segmentBase, drmSchemeDatas);
+    return new RepresentationInfo(format, baseUrl, segmentBase, drmSchemeDatas, inbandEventStreams);
   }
 
   protected Format buildFormat(String id, String containerMimeType, int width, int height,
@@ -850,13 +900,15 @@ private static final class RepresentationInfo {
     public final String baseUrl;
     public final SegmentBase segmentBase;
     public final ArrayList<SchemeData> drmSchemeDatas;
+    public final ArrayList<InbandEventStream> inbandEventStreams;
 
     public RepresentationInfo(Format format, String baseUrl, SegmentBase segmentBase,
-        ArrayList<SchemeData> drmSchemeDatas) {
+        ArrayList<SchemeData> drmSchemeDatas, ArrayList<InbandEventStream> inbandEventStreams) {
       this.format = format;
       this.baseUrl = baseUrl;
       this.segmentBase = segmentBase;
       this.drmSchemeDatas = drmSchemeDatas;
+      this.inbandEventStreams = inbandEventStreams;
     }
 
   }

library/src/main/java/com/google/android/exoplayer2/source/dash/manifest/InbandEventStream.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2014 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.dash.manifest;
+
+import com.google.android.exoplayer2.util.Util;
+
+/**
+ * Represents a DASH in-band event stream.
+ */
+public class InbandEventStream {
+
+  public final String schemeIdUri;
+  public final String value;
+
+  public InbandEventStream(String schemeIdUri, String value) {
+    this.schemeIdUri = schemeIdUri;
+    this.value = value;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if (obj == null || getClass() != obj.getClass()) {
+      return false;
+    }
+    InbandEventStream other = (InbandEventStream) obj;
+    return Util.areEqual(schemeIdUri, other.schemeIdUri) && Util.areEqual(value, other.value);
+  }
+
+  @Override
+  public int hashCode() {
+    return 31 * (schemeIdUri != null ? schemeIdUri.hashCode() : 0)
+        + (value != null ? value.hashCode() : 0);
+  }
+
+}