Text support for MpdBuilder

Change-Id: I75e1da391356e9edfcb520941029341941c31332

packager/mpd/base/dash_iop_mpd_notifier.cc

@@ -77,11 +77,19 @@ bool DashIopMpdNotifier::NotifyNewContainer(const MediaInfo& media_info,
   std::string lang;
   if (media_info.has_audio_info()) {
     lang = media_info.audio_info().language();
+  } else if (media_info.has_text_info()) {
+    lang = media_info.text_info().language();
   }
 
   AdaptationSet* adaptation_set =
       GetAdaptationSetForMediaInfo(media_info, content_type, lang);
   DCHECK(adaptation_set);
+  if (media_info.has_text_info()) {
+    // IOP requires all AdaptationSets to have (sub)segmentAlignment set to
+    // true, so carelessly set it to true.
+    // In practice it doesn't really make sense to adapt between text tracks.
+    adaptation_set->ForceSetSegmentAlignment(true);
+  }
 
   MediaInfo adjusted_media_info(media_info);
   MpdBuilder::MakePathsRelativeToMpd(output_path_, &adjusted_media_info);

packager/mpd/base/dash_iop_mpd_notifier_unittest.cc

@@ -135,7 +135,9 @@ class DashIopMpdNotifierTest
   const MpdOptions empty_mpd_option_;
   const std::vector<std::string> empty_base_urls_;
 
-  // Default AdaptationSet mock.
+  // Default mocks that can be used for the tests.
+  // IOW, if a test only requires one instance of
+  // Mock{AdaptationSet,Representation}, these can be used.
   scoped_ptr<MockAdaptationSet> default_mock_adaptation_set_;
   scoped_ptr<MockRepresentation> default_mock_representation_;
 
@@ -181,6 +183,38 @@ TEST_P(DashIopMpdNotifierTest, NotifyNewContainer) {
   EXPECT_TRUE(notifier.Flush());
 }
 
+// Verify that if the MediaInfo contains text information, then
+// MpdBuilder::ForceSetSegmentAlignment() is called.
+TEST_P(DashIopMpdNotifierTest, NotifyNewTextContainer) {
+  const char kTextMediaInfo[] =
+      "text_info {\n"
+      "  format: 'ttml'\n"
+      "  language: 'en'\n"
+      "}\n"
+      "container_type: CONTAINER_TEXT\n";
+  DashIopMpdNotifier notifier(dash_profile(), empty_mpd_option_,
+                              empty_base_urls_, output_path_);
+
+  scoped_ptr<MockMpdBuilder> mock_mpd_builder(new MockMpdBuilder(mpd_type()));
+
+  EXPECT_CALL(*mock_mpd_builder, AddAdaptationSet(StrEq("en")))
+      .WillOnce(Return(default_mock_adaptation_set_.get()));
+  EXPECT_CALL(*default_mock_adaptation_set_, AddRole(_)).Times(0);
+  EXPECT_CALL(*default_mock_adaptation_set_, ForceSetSegmentAlignment(true));
+  EXPECT_CALL(*default_mock_adaptation_set_, AddRepresentation(_))
+      .WillOnce(Return(default_mock_representation_.get()));
+
+  // This is for the Flush() below but adding expectation here because the next
+  // lines Pass() the pointer.
+  EXPECT_CALL(*mock_mpd_builder, ToString(_)).WillOnce(Return(true));
+
+  uint32_t unused_container_id;
+  SetMpdBuilder(&notifier, mock_mpd_builder.Pass());
+  EXPECT_TRUE(notifier.NotifyNewContainer(ConvertToMediaInfo(kTextMediaInfo),
+                                          &unused_container_id));
+  EXPECT_TRUE(notifier.Flush());
+}
+
 // Verify VOD NotifyNewContainer() operation works with different
 // MediaInfo::ProtectedContent.
 // Two AdaptationSets should be created.

packager/mpd/base/media_info.proto

@@ -16,6 +16,7 @@ message MediaInfo {
     CONTAINER_MP4 = 1;
     CONTAINER_MPEG2_TS= 2;
     CONTAINER_WEBM = 3;
+    CONTAINER_TEXT = 4;
   }
 
   message VideoInfo {
@@ -51,8 +52,14 @@ message MediaInfo {
   }
 
   message TextInfo {
+    enum TextType {
+      UNKNOWN = 0;
+      CAPTION = 1;
+      SUBTITLE = 2;
+    }
     optional string format = 1;
     optional string language = 2;
+    optional TextType type = 3;
   }
 
   message ProtectedContent {

packager/mpd/base/mock_mpd_builder.h

@@ -38,6 +38,7 @@ class MockAdaptationSet : public AdaptationSet {
   MOCK_METHOD2(UpdateContentProtectionPssh,
                void(const std::string& drm_uuid, const std::string& pssh));
   MOCK_METHOD1(AddRole, void(AdaptationSet::Role role));
+  MOCK_METHOD1(ForceSetSegmentAlignment, void(bool segment_alignment));
 
   MOCK_METHOD1(SetGroup, void(int group_number));
   MOCK_CONST_METHOD0(Group, int());

packager/mpd/base/mpd_builder.cc

@@ -39,6 +39,22 @@ namespace {
 
 const int kAdaptationSetGroupNotSet = -1;
 
+AdaptationSet::Role MediaInfoTextTypeToRole(MediaInfo::TextInfo::TextType type) {
+  switch (type) {
+    case MediaInfo::TextInfo::UNKNOWN:
+      LOG(WARNING) << "Unknown text type, assuming subtitle.";
+      return AdaptationSet::kRoleSubtitle;
+    case MediaInfo::TextInfo::CAPTION:
+      return AdaptationSet::kRoleCaption;
+    case MediaInfo::TextInfo::SUBTITLE:
+      return AdaptationSet::kRoleSubtitle;
+    default:
+      NOTREACHED() << "Unknown MediaInfo TextType: " << type
+                   << " assuming subtitle.";
+      return AdaptationSet::kRoleSubtitle;
+  }
+}
+
 std::string GetMimeType(const std::string& prefix,
                         MediaInfo::ContainerType container_type) {
   switch (container_type) {
@@ -54,7 +70,7 @@ std::string GetMimeType(const std::string& prefix,
   }
 
   // Unsupported container types should be rejected/handled by the caller.
-  NOTREACHED() << "Unrecognized container type: " << container_type;
+  LOG(ERROR) << "Unrecognized container type: " << container_type;
   return std::string();
 }
 
@@ -684,6 +700,13 @@ Representation* AdaptationSet::AddRepresentation(const MediaInfo& media_info) {
     content_type_ = "video";
   } else if (media_info.has_audio_info()) {
     content_type_ = "audio";
+  } else if (media_info.has_text_info()) {
+    content_type_ = "text";
+
+    if (media_info.text_info().has_type() &&
+        (media_info.text_info().type() != MediaInfo::TextInfo::UNKNOWN)) {
+      roles_.insert(MediaInfoTextTypeToRole(media_info.text_info().type()));
+    }
   }
 
   representations_.push_back(representation.get());
@@ -998,20 +1021,20 @@ Representation::Representation(
 Representation::~Representation() {}
 
 bool Representation::Init() {
-  codecs_ = GetCodecs(media_info_);
+  if (!AtLeastOneTrue(media_info_.has_video_info(),
-  if (codecs_.empty()) {
+                      media_info_.has_audio_info(),
-    LOG(ERROR) << "Missing codec info in MediaInfo.";
+                      media_info_.has_text_info())) {
-    return false;
-  }
-
-  const bool has_video_info = media_info_.has_video_info();
-  const bool has_audio_info = media_info_.has_audio_info();
-
-  if (!has_video_info && !has_audio_info) {
     // This is an error. Segment information can be in AdaptationSet, Period, or
     // MPD but the interface does not provide a way to set them.
     // See 5.3.9.1 ISO 23009-1:2012 for segment info.
-    LOG(ERROR) << "Representation needs video or audio.";
+    LOG(ERROR) << "Representation needs one of video, audio, or text.";
+    return false;
+  }
+
+  if (MoreThanOneTrue(media_info_.has_video_info(),
+                      media_info_.has_audio_info(),
+                      media_info_.has_text_info())) {
+    LOG(ERROR) << "Only one of VideoInfo, AudioInfo, or TextInfo can be set.";
     return false;
   }
 
@@ -1020,18 +1043,22 @@ bool Representation::Init() {
     return false;
   }
 
-  // For mimetypes, this checks the video and then audio. Usually when there is
+  if (media_info_.has_video_info()) {
-  // audio + video, we take video/<type>.
-  if (has_video_info) {
     mime_type_ = GetVideoMimeType();
     if (!HasRequiredVideoFields(media_info_.video_info())) {
       LOG(ERROR) << "Missing required fields to create a video Representation.";
       return false;
     }
-  } else if (has_audio_info) {
+  } else if (media_info_.has_audio_info()) {
     mime_type_ = GetAudioMimeType();
+  } else if (media_info_.has_text_info()) {
+    mime_type_ = GetTextMimeType();
   }
 
+  if (mime_type_.empty())
+    return false;
+
+  codecs_ = GetCodecs(media_info_);
   return true;
 }
 
@@ -1110,7 +1137,8 @@ xml::ScopedXmlPtr<xmlNode>::type Representation::GetXml() {
   // Mandatory fields for Representation.
   representation.SetId(id_);
   representation.SetIntegerAttribute("bandwidth", bandwidth);
-  representation.SetStringAttribute("codecs", codecs_);
+  if (!codecs_.empty()) 
+    representation.SetStringAttribute("codecs", codecs_);
   representation.SetStringAttribute("mimeType", mime_type_);
 
   const bool has_video_info = media_info_.has_video_info();
@@ -1285,6 +1313,35 @@ std::string Representation::GetAudioMimeType() const {
   return GetMimeType("audio", media_info_.container_type());
 }
 
+std::string Representation::GetTextMimeType() const {
+  CHECK(media_info_.has_text_info());
+  if (media_info_.text_info().format() == "ttml") {
+    switch (media_info_.container_type()) {
+      case MediaInfo::CONTAINER_TEXT:
+        return "application/ttml+xml";
+      case MediaInfo::CONTAINER_MP4:
+        return "application/mp4";
+      default:
+        LOG(ERROR) << "Failed to determine MIME type for TTML container: "
+                   << media_info_.container_type();
+        return "";
+    }
+  }
+  if (media_info_.text_info().format() == "vtt") {
+    if (media_info_.container_type() == MediaInfo::CONTAINER_TEXT) {
+      return "text/vtt";
+    }
+    LOG(ERROR) << "Failed to determine MIME type for VTT container: "
+               << media_info_.container_type();
+    return "";
+  }
+
+  LOG(ERROR) << "Cannot determine MIME type for format: "
+             << media_info_.text_info().format()
+             << " container: " << media_info_.container_type();
+  return "";
+}
+
 bool Representation::GetEarliestTimestamp(double* timestamp_seconds) {
   DCHECK(timestamp_seconds);
 

packager/mpd/base/mpd_builder.h

@@ -172,7 +172,8 @@ class AdaptationSet {
 
   /// Create a Representation instance using @a media_info.
   /// @param media_info is a MediaInfo object used to initialize the returned
-  ///        Representation instance.
+  ///        Representation instance. It may contain only one of VideoInfo,
+  ///        AudioInfo, or TextInfo, i.e. VideoInfo XOR AudioInfo XOR TextInfo.
   /// @return On success, returns a pointer to Representation. Otherwise returns
   ///         NULL. The returned pointer is owned by the AdaptationSet instance.
   virtual Representation* AddRepresentation(const MediaInfo& media_info);
@@ -220,7 +221,7 @@ class AdaptationSet {
   /// for the AdaptationSet.
   /// @param segment_alignment is the value used for (sub)segmentAlignment
   ///        attribute.
-  void ForceSetSegmentAlignment(bool segment_alignment);
+  virtual void ForceSetSegmentAlignment(bool segment_alignment);
 
   /// Sets the AdaptationSet@group attribute.
   /// Passing a negative value to this method will unset the attribute.
@@ -517,11 +518,14 @@ class Representation {
   // strings.
   std::string GetVideoMimeType() const;
   std::string GetAudioMimeType() const;
+  std::string GetTextMimeType() const;
 
   // Gets the earliest, normalized segment timestamp. Returns true if
   // successful, false otherwise.
   bool GetEarliestTimestamp(double* timestamp_seconds);
 
+  // Init() checks that only one of VideoInfo, AudioInfo, or TextInfo is set. So
+  // any logic using this can assume only one set.
   MediaInfo media_info_;
   std::list<ContentProtectionElement> content_protection_elements_;
   std::list<SegmentInfo> segment_infos_;

packager/mpd/base/mpd_builder_unittest.cc

@@ -414,6 +414,42 @@ TEST_F(CommonMpdBuilderTest, ValidMediaInfo) {
   EXPECT_TRUE(representation->Init());
 }
 
+// Verify that if VideoInfo, AudioInfo, or TextInfo is not set, Init() fails.
+TEST_F(CommonMpdBuilderTest, VideoAudioTextInfoNotSet) {
+  const char kTestMediaInfo[] = "container_type: 1";
+
+  auto representation =
+      CreateRepresentation(ConvertToMediaInfo(kTestMediaInfo), MpdOptions(),
+                           kAnyRepresentationId, NoListener());
+  EXPECT_FALSE(representation->Init());
+}
+
+// Verify that if more than one of VideoInfo, AudioInfo, or TextInfo is set,
+// then Init() fails.
+TEST_F(CommonMpdBuilderTest, VideoAndAudioInfoSet) {
+  const char kTestMediaInfo[] =
+      "video_info {\n"
+      "  codec: 'avc1'\n"
+      "  height: 480\n"
+      "  time_scale: 10\n"
+      "  frame_duration: 10\n"
+      "  pixel_width: 1\n"
+      "  pixel_height: 1\n"
+      "}\n"
+      "audio_info {\n"
+      "  codec: 'mp4a.40.2'\n"
+      "  sampling_frequency: 44100\n"
+      "  time_scale: 1200\n"
+      "  num_channels: 2\n"
+      "}\n"
+      "container_type: CONTAINER_MP4\n";
+
+  auto representation =
+      CreateRepresentation(ConvertToMediaInfo(kTestMediaInfo), MpdOptions(),
+                           kAnyRepresentationId, NoListener());
+  EXPECT_FALSE(representation->Init());
+}
+
 // Verify that Representation::Init() fails if a required field is missing.
 TEST_F(CommonMpdBuilderTest, InvalidMediaInfo) {
   // Missing width.
@@ -538,16 +574,15 @@ TEST_F(CommonMpdBuilderTest, CheckAdaptationSetVideoContentType) {
       "  pixel_width: 1\n"
       "  pixel_height: 1\n"
       "}\n"
-      "container_type: 1\n";
+      "container_type: CONTAINER_MP4\n";
 
   auto adaptation_set =
       CreateAdaptationSet(kAnyAdaptationSetId, "", MpdOptions(),
                           MpdBuilder::kStatic, &sequence_counter);
   adaptation_set->AddRepresentation(ConvertToMediaInfo(kVideoMediaInfo));
 
-  xml::ScopedXmlPtr<xmlNode>::type node_xml(adaptation_set->GetXml());
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
-  EXPECT_NO_FATAL_FAILURE(
+      "contentType", "video", adaptation_set->GetXml().get()));
-      ExpectAttributeEqString("contentType", "video", node_xml.get()));
 }
 
 // Verify that content type is set correctly if audio info is present in
@@ -561,40 +596,100 @@ TEST_F(CommonMpdBuilderTest, CheckAdaptationSetAudioContentType) {
       "  time_scale: 1200\n"
       "  num_channels: 2\n"
       "}\n"
-      "container_type: 1\n";
+      "container_type: CONTAINER_MP4\n";
 
   auto adaptation_set =
       CreateAdaptationSet(kAnyAdaptationSetId, "", MpdOptions(),
                           MpdBuilder::kStatic, &sequence_counter);
   adaptation_set->AddRepresentation(ConvertToMediaInfo(kAudioMediaInfo));
 
-  xml::ScopedXmlPtr<xmlNode>::type node_xml(adaptation_set->GetXml());
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
-  EXPECT_NO_FATAL_FAILURE(
+      "contentType", "audio", adaptation_set->GetXml().get()));
-      ExpectAttributeEqString("contentType", "audio", node_xml.get()));
 }
 
 // Verify that content type is set correctly if text info is present in
 // MediaInfo.
-// TODO(rkuroiwa): Enable this once text support is implemented.
+TEST_F(CommonMpdBuilderTest, CheckAdaptationSetTextContentType) {
-// This fails because it fails to get the codec, therefore Representation
-// creation fails.
-TEST_F(CommonMpdBuilderTest, DISABLED_CheckAdaptationSetTextContentType) {
   base::AtomicSequenceNumber sequence_counter;
   const char kTextMediaInfo[] =
       "text_info {\n"
       "  format: 'ttml'\n"
       "  language: 'en'\n"
       "}\n"
-      "container_type: 1\n";
+      "container_type: CONTAINER_TEXT\n";
 
   auto adaptation_set =
       CreateAdaptationSet(kAnyAdaptationSetId, "", MpdOptions(),
                           MpdBuilder::kStatic, &sequence_counter);
   adaptation_set->AddRepresentation(ConvertToMediaInfo(kTextMediaInfo));
 
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
+      "contentType", "text", adaptation_set->GetXml().get()));
+}
+
+TEST_F(CommonMpdBuilderTest, TtmlXmlMimeType) {
+  const char kTtmlXmlMediaInfo[] =
+      "text_info {\n"
+      "  format: 'ttml'\n"
+      "}\n"
+      "container_type: CONTAINER_TEXT\n";
+
+  auto representation =
+      CreateRepresentation(ConvertToMediaInfo(kTtmlXmlMediaInfo), MpdOptions(),
+                           kAnyRepresentationId, NoListener());
+  EXPECT_TRUE(representation->Init());
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
+      "mimeType", "application/ttml+xml", representation->GetXml().get()));
+}
+
+TEST_F(CommonMpdBuilderTest, TtmlMp4MimeType) {
+  const char kTtmlMp4MediaInfo[] =
+      "text_info {\n"
+      "  format: 'ttml'\n"
+      "}\n"
+      "container_type: CONTAINER_MP4\n";
+
+  auto representation =
+      CreateRepresentation(ConvertToMediaInfo(kTtmlMp4MediaInfo), MpdOptions(),
+                           kAnyRepresentationId, NoListener()).Pass();
+  EXPECT_TRUE(representation->Init());
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
+      "mimeType", "application/mp4", representation->GetXml().get()));
+}
+
+TEST_F(CommonMpdBuilderTest, WebVttMimeType) {
+  const char kWebVttMediaInfo[] =
+      "text_info {\n"
+      "  format: 'vtt'\n"
+      "}\n"
+      "container_type: CONTAINER_TEXT\n";
+
+  auto representation =
+      CreateRepresentation(ConvertToMediaInfo(kWebVttMediaInfo), MpdOptions(),
+                           kAnyRepresentationId, NoListener()).Pass();
+  EXPECT_TRUE(representation->Init());
+  EXPECT_NO_FATAL_FAILURE(ExpectAttributeEqString(
+      "mimeType", "text/vtt", representation->GetXml().get()));
+}
+
+// Verify that language passed to the constructor sets the @lang field is set.
+TEST_F(CommonMpdBuilderTest, CheckLanguageAttributeSet) {
+  base::AtomicSequenceNumber sequence_counter;
+  // The media info doesn't really matter as long as it is valid.
+  const char kTextMediaInfo[] =
+      "text_info {\n"
+      "  format: 'ttml'\n"
+      "}\n"
+      "container_type: CONTAINER_TEXT\n";
+
+  auto adaptation_set =
+      CreateAdaptationSet(kAnyAdaptationSetId, "en", MpdOptions(),
+                          MpdBuilder::kStatic, &sequence_counter);
+  adaptation_set->AddRepresentation(ConvertToMediaInfo(kTextMediaInfo));
+
   xml::ScopedXmlPtr<xmlNode>::type node_xml(adaptation_set->GetXml());
   EXPECT_NO_FATAL_FAILURE(
-      ExpectAttributeEqString("contentType", "text", node_xml.get()));
+      ExpectAttributeEqString("lang", "en", node_xml.get()));
 }
 
 TEST_F(CommonMpdBuilderTest, CheckAdaptationSetId) {
@@ -1621,6 +1716,54 @@ TEST_F(StaticMpdBuilderTest, WriteToFile) {
   EXPECT_TRUE(DeleteFile(file_path, kNonRecursive));
 }
 
+// Verify that a text path works.
+TEST_F(StaticMpdBuilderTest, Text) {
+  const char kTextMediaInfo[] =
+      "text_info {\n"
+      "  format: 'ttml'\n"
+      "  language: 'en'\n"
+      "  type: SUBTITLE\n"
+      "}\n"
+      "media_duration_seconds: 35\n"
+      "bandwidth: 1000\n"
+      "media_file_name: 'subtitle.xml'\n"
+      "container_type: CONTAINER_TEXT\n";
+
+  const char kExpectedOutput[] =
+      "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+      "<MPD xmlns=\"urn:mpeg:DASH:schema:MPD:2011\""
+      " xmlns:cenc=\"urn:mpeg:cenc:2013\""
+      " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
+      " xmlns:xlink=\"http://www.w3.org/1999/xlink\""
+      " xsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011 DASH-MPD.xsd\""
+      " minBufferTime=\"PT2S\" type=\"static\""
+      " profiles=\"urn:mpeg:dash:profile:isoff-on-demand:2011\""
+      " mediaPresentationDuration=\"PT35S\">"
+      "  <Period>"
+      "    <AdaptationSet id=\"0\" contentType=\"text\" lang=\"en\">"
+      "      <Role schemeIdUri=\"urn:mpeg:dash:role:2011\""
+      "       value=\"subtitle\"/>\n"
+      "      <Representation id=\"0\" bandwidth=\"1000\""
+      "       mimeType=\"application/ttml+xml\">"
+      "        <BaseURL>subtitle.xml</BaseURL>"
+      "      </Representation>"
+      "    </AdaptationSet>"
+      "  </Period>"
+      "</MPD>";
+
+  AdaptationSet* text_adaptation_set = mpd_.AddAdaptationSet("en");
+  ASSERT_TRUE(text_adaptation_set);
+
+  Representation* text_representation = text_adaptation_set->AddRepresentation(
+      ConvertToMediaInfo(kTextMediaInfo));
+  ASSERT_TRUE(text_representation);
+
+  std::string mpd_output;
+  ASSERT_TRUE(mpd_.ToString(&mpd_output));
+  ASSERT_TRUE(ValidateMpdSchema(mpd_output));
+  EXPECT_TRUE(XmlEqual(kExpectedOutput, mpd_output));
+}
+
 // Check whether the attributes are set correctly for dynamic <MPD> element.
 // This test must use ASSERT_EQ for comparison because XmlEqual() cannot
 // handle namespaces correctly yet.

packager/mpd/base/mpd_utils.cc

@@ -13,6 +13,24 @@
 #include "packager/mpd/base/xml/scoped_xml_ptr.h"
 
 namespace edash_packager {
+namespace {
+
+std::string TextCodecString(
+    const edash_packager::MediaInfo& media_info) {
+  CHECK(media_info.has_text_info());
+  const std::string& format = media_info.text_info().format();
+  // DASH IOP mentions that the codec for ttml in mp4 is stpp.
+  if (format == "ttml" &&
+      (media_info.container_type() == MediaInfo::CONTAINER_MP4)) {
+    return "stpp";
+  }
+
+  // Otherwise codec doesn't need to be specified, e.g. vtt and ttml+xml are
+  // obvious from the mime type.
+  return "";
+}
+
+}  // namespace
 
 bool HasVODOnlyFields(const MediaInfo& media_info) {
   return media_info.has_init_range() || media_info.has_index_range() ||
@@ -40,22 +58,19 @@ void RemoveDuplicateAttributes(
 }
 
 std::string GetCodecs(const MediaInfo& media_info) {
-  std::string video_codec;
+  CHECK(OnlyOneTrue(media_info.has_video_info(), media_info.has_audio_info(),
+                    media_info.has_text_info()));
+
   if (media_info.has_video_info())
-    video_codec = media_info.video_info().codec();
+    return media_info.video_info().codec();
 
-  std::string audio_codec;
   if (media_info.has_audio_info())
-    audio_codec = media_info.audio_info().codec();
+    return media_info.audio_info().codec();
 
-  if (!video_codec.empty() && !audio_codec.empty()) {
+  if (media_info.has_text_info())
-    return video_codec + "," + audio_codec;
+    return TextCodecString(media_info);
-  } else if (!video_codec.empty()) {
-    return video_codec;
-  } else if (!audio_codec.empty()) {
-    return audio_codec;
-  }
 
+  NOTREACHED();
   return "";
 }
 

packager/mpd/base/simple_mpd_notifier.cc

@@ -49,6 +49,8 @@ bool SimpleMpdNotifier::NotifyNewContainer(const MediaInfo& media_info,
   std::string lang;
   if (media_info.has_audio_info()) {
     lang = media_info.audio_info().language();
+  } else if (media_info.has_text_info()) {
+    lang = media_info.text_info().language();
   }
   AdaptationSet** adaptation_set = &adaptation_set_map_[content_type][lang];
   if (*adaptation_set == NULL)