diff --git a/packager/mpd/base/dash_iop_mpd_notifier.cc b/packager/mpd/base/dash_iop_mpd_notifier.cc
index 2b3daa5f62..25900c06fd 100644
--- a/packager/mpd/base/dash_iop_mpd_notifier.cc
+++ b/packager/mpd/base/dash_iop_mpd_notifier.cc
@@ -248,6 +248,18 @@ AdaptationSet* DashIopMpdNotifier::NewAdaptationSet(
     AddContentProtectionElements(media_info, new_adaptation_set);
   }
   adaptation_sets->push_back(new_adaptation_set);
+
+  if (media_info.has_video_info()) {
+    // Because 'lang' is ignored for videos, |adaptation_sets| must have
+    // all the video AdaptationSets.
+    if (adaptation_sets->size() > 2) {
+      new_adaptation_set->AddRole(AdaptationSet::kRoleMain);
+    } else if (adaptation_sets->size() == 2) {
+      // Set "main" Role for both AdaptatoinSets.
+      (*adaptation_sets->begin())->AddRole(AdaptationSet::kRoleMain);
+      new_adaptation_set->AddRole(AdaptationSet::kRoleMain);
+    }
+  }
   return new_adaptation_set;
 }
 
diff --git a/packager/mpd/base/dash_iop_mpd_notifier.h b/packager/mpd/base/dash_iop_mpd_notifier.h
index 7d4c00cc8c..859f21d5b9 100644
--- a/packager/mpd/base/dash_iop_mpd_notifier.h
+++ b/packager/mpd/base/dash_iop_mpd_notifier.h
@@ -22,8 +22,10 @@ namespace edash_packager {
 
 /// This class is an MpdNotifier which will try its best to generate a
 /// DASH IF IOPv3 compliant MPD.
-/// For example, all <ContentProtection> elements must be right under
+/// e.g.
+/// All <ContentProtection> elements must be right under
 /// <AdaptationSet> and cannot be under <Representation>.
+/// All video Adaptation Sets have Role set to "main".
 class DashIopMpdNotifier : public MpdNotifier {
  public:
   DashIopMpdNotifier(DashProfile dash_profile,
diff --git a/packager/mpd/base/dash_iop_mpd_notifier_unittest.cc b/packager/mpd/base/dash_iop_mpd_notifier_unittest.cc
index b25bc4ba30..39c559f648 100644
--- a/packager/mpd/base/dash_iop_mpd_notifier_unittest.cc
+++ b/packager/mpd/base/dash_iop_mpd_notifier_unittest.cc
@@ -165,6 +165,7 @@ TEST_P(DashIopMpdNotifierTest, NotifyNewContainer) {
 
   EXPECT_CALL(*mock_mpd_builder, AddAdaptationSet(_))
       .WillOnce(Return(default_mock_adaptation_set_.get()));
+  EXPECT_CALL(*default_mock_adaptation_set_, AddRole(_)).Times(0);
   EXPECT_CALL(*default_mock_adaptation_set_, AddRepresentation(_))
       .WillOnce(Return(default_mock_representation_.get()));
 
@@ -286,6 +287,11 @@ TEST_P(DashIopMpdNotifierTest,
       .WillOnce(Return(hd_adaptation_set.get()));
   // Called twice for the same reason as above.
   EXPECT_CALL(*hd_adaptation_set, AddContentProtectionElement(_)).Times(2);
+
+  // Add main Role here for both.
+  EXPECT_CALL(*sd_adaptation_set, AddRole(AdaptationSet::kRoleMain));
+  EXPECT_CALL(*hd_adaptation_set, AddRole(AdaptationSet::kRoleMain));
+
   EXPECT_CALL(*hd_adaptation_set, AddRepresentation(_))
       .WillOnce(Return(hd_representation.get()));
 
@@ -382,6 +388,7 @@ TEST_P(DashIopMpdNotifierTest, NotifyNewContainersWithSameProtectedContent) {
       AddContentProtectionElement(ContentProtectionElementEq(mp4_protection)));
   EXPECT_CALL(*default_mock_adaptation_set_,
               AddContentProtectionElement(ContentProtectionElementEq(my_drm)));
+  EXPECT_CALL(*default_mock_adaptation_set_, AddRole(_)).Times(0);
   EXPECT_CALL(*default_mock_adaptation_set_, AddRepresentation(_))
       .WillOnce(Return(sd_representation.get()));
   if (mpd_type() == MpdBuilder::kStatic)
@@ -392,6 +399,7 @@ TEST_P(DashIopMpdNotifierTest, NotifyNewContainersWithSameProtectedContent) {
   EXPECT_CALL(*mock_mpd_builder, AddAdaptationSet(_)).Times(0);
   EXPECT_CALL(*default_mock_adaptation_set_, AddContentProtectionElement(_))
       .Times(0);
+  EXPECT_CALL(*default_mock_adaptation_set_, AddRole(_)).Times(0);
   EXPECT_CALL(*default_mock_adaptation_set_, AddRepresentation(_))
       .WillOnce(Return(hd_representation.get()));
   if (mpd_type() == MpdBuilder::kStatic)
@@ -635,12 +643,12 @@ TEST_P(DashIopMpdNotifierTest, DoNotSetGroupIfContentTypesDifferent) {
       "container_type: 1\n"
       "media_duration_seconds: 10.5\n";
 
-  const uint32_t kSdAdaptationSetId = 6u;
-  const uint32_t kHdAdaptationSetId = 7u;
+  const uint32_t kVideoAdaptationSetId = 6u;
+  const uint32_t kAudioAdaptationSetId = 7u;
   scoped_ptr<MockAdaptationSet> video_adaptation_set(
-      new MockAdaptationSet(kSdAdaptationSetId));
+      new MockAdaptationSet(kVideoAdaptationSetId));
   scoped_ptr<MockAdaptationSet> audio_adaptation_set(
-      new MockAdaptationSet(kHdAdaptationSetId));
+      new MockAdaptationSet(kAudioAdaptationSetId));
 
   ON_CALL(*video_adaptation_set, Group())
       .WillByDefault(Return(kDefaultGroupId));
@@ -651,27 +659,29 @@ TEST_P(DashIopMpdNotifierTest, DoNotSetGroupIfContentTypesDifferent) {
   EXPECT_CALL(*video_adaptation_set, SetGroup(_)).Times(0);
   EXPECT_CALL(*audio_adaptation_set, SetGroup(_)).Times(0);
 
-  const uint32_t kSdRepresentation = 8u;
-  const uint32_t kHdRepresentation = 9u;
-  scoped_ptr<MockRepresentation> sd_representation(
-      new MockRepresentation(kSdRepresentation));
-  scoped_ptr<MockRepresentation> hd_representation(
-      new MockRepresentation(kHdRepresentation));
+  const uint32_t kVideoRepresentation = 8u;
+  const uint32_t kAudioRepresentation = 9u;
+  scoped_ptr<MockRepresentation> video_representation(
+      new MockRepresentation(kVideoRepresentation));
+  scoped_ptr<MockRepresentation> audio_representation(
+      new MockRepresentation(kAudioRepresentation));
 
   InSequence in_sequence;
   EXPECT_CALL(*mock_mpd_builder, AddAdaptationSet(_))
       .WillOnce(Return(video_adaptation_set.get()));
   EXPECT_CALL(*video_adaptation_set, AddContentProtectionElement(_)).Times(2);
+  EXPECT_CALL(*video_adaptation_set, AddRole(_)).Times(0);
   EXPECT_CALL(*video_adaptation_set, AddRepresentation(_))
-      .WillOnce(Return(sd_representation.get()));
+      .WillOnce(Return(video_representation.get()));
   if (mpd_type() == MpdBuilder::kStatic)
     EXPECT_CALL(*mock_mpd_builder, ToString(_)).WillOnce(Return(true));
 
   EXPECT_CALL(*mock_mpd_builder, AddAdaptationSet(_))
       .WillOnce(Return(audio_adaptation_set.get()));
   EXPECT_CALL(*audio_adaptation_set, AddContentProtectionElement(_)).Times(2);
+  EXPECT_CALL(*audio_adaptation_set, AddRole(_)).Times(0);
   EXPECT_CALL(*audio_adaptation_set, AddRepresentation(_))
-      .WillOnce(Return(hd_representation.get()));
+      .WillOnce(Return(audio_representation.get()));
 
   if (mpd_type() == MpdBuilder::kStatic)
     EXPECT_CALL(*mock_mpd_builder, ToString(_)).WillOnce(Return(true));
diff --git a/packager/mpd/base/mock_mpd_builder.h b/packager/mpd/base/mock_mpd_builder.h
index 76e66d3d46..eed8bde477 100644
--- a/packager/mpd/base/mock_mpd_builder.h
+++ b/packager/mpd/base/mock_mpd_builder.h
@@ -35,6 +35,7 @@ class MockAdaptationSet : public AdaptationSet {
   MOCK_METHOD1(AddRepresentation, Representation*(const MediaInfo& media_info));
   MOCK_METHOD1(AddContentProtectionElement,
                void(const ContentProtectionElement& element));
+  MOCK_METHOD1(AddRole, void(AdaptationSet::Role role));
 
   MOCK_METHOD1(SetGroup, void(int group_number));
   MOCK_CONST_METHOD0(Group, int());
diff --git a/packager/mpd/base/mpd_builder.h b/packager/mpd/base/mpd_builder.h
index 359d83711f..dca550c9fb 100644
--- a/packager/mpd/base/mpd_builder.h
+++ b/packager/mpd/base/mpd_builder.h
@@ -194,7 +194,7 @@ class AdaptationSet {
   /// The Role element's is schemeIdUri='urn:mpeg:dash:role:2011'.
   /// See ISO/IEC 23009-1:2012 section 5.8.5.5.
   /// @param role of this AdaptationSet.
-  void AddRole(Role role);
+  virtual void AddRole(Role role);
 
   /// Makes a copy of AdaptationSet xml element with its child Representation
   /// and ContentProtection elements.