Add HLS audio language support

Before this, HLS output did not contain language information.
Now, media playlists are properly tagged with a language in the
master playlist.

b/36134267

Change-Id: I172e946dbedd096a44cb2f917b007cc004756228

packager/app/stream_descriptor.cc

@@ -11,7 +11,7 @@
 #include "packager/base/strings/string_number_conversions.h"
 #include "packager/base/strings/string_split.h"
 #include "packager/media/base/container_names.h"
-#include "packager/mpd/base/language_utils.h"
+#include "packager/media/base/language_utils.h"
 
 namespace shaka {
 namespace media {

packager/hls/base/master_playlist.cc

@@ -121,8 +121,18 @@ bool MasterPlaylist::WriteMasterPlaylist(const std::string& base_url,
     for (const MediaPlaylist* audio_playlist : audio_playlists) {
       base::StringAppendF(
           &audio_output,
-          "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"%s\",NAME=\"%s\",URI=\"%s\"\n",
-          group_id.c_str(), audio_playlist->name().c_str(),
+          "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"%s\",NAME=\"%s\",",
+          group_id.c_str(), audio_playlist->name().c_str());
+      std::string language = audio_playlist->GetLanguage();
+      if (!language.empty()) {
+        base::StringAppendF(
+            &audio_output,
+            "LANGUAGE=\"%s\",",
+            language.c_str());
+      }
+      base::StringAppendF(
+          &audio_output,
+          "URI=\"%s\"\n",
           (base_url + audio_playlist->file_name()).c_str());
       const uint64_t audio_bitrate = audio_playlist->Bitrate();
       if (audio_bitrate > max_audio_bitrate)

packager/hls/base/master_playlist_unittest.cc

@@ -130,6 +130,7 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistVideoAndAudio) {
   std::string audio_codec = "audiocodec";
   MockMediaPlaylist english_playlist(kVodPlaylist, "eng.m3u8", "english",
                                      "audiogroup");
+  EXPECT_CALL(english_playlist, GetLanguage()).WillRepeatedly(Return("en"));
   english_playlist.SetStreamTypeForTesting(
       MediaPlaylist::MediaPlaylistStreamType::kPlayListAudio);
   english_playlist.SetCodecForTesting(audio_codec);
@@ -141,6 +142,7 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistVideoAndAudio) {
   // Second audio, spanish.m3u8.
   MockMediaPlaylist spanish_playlist(kVodPlaylist, "spa.m3u8", "espanol",
                                      "audiogroup");
+  EXPECT_CALL(spanish_playlist, GetLanguage()).WillRepeatedly(Return("es"));
   spanish_playlist.SetStreamTypeForTesting(
       MediaPlaylist::MediaPlaylistStreamType::kPlayListAudio);
   spanish_playlist.SetCodecForTesting(audio_codec);
@@ -166,9 +168,9 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistVideoAndAudio) {
       "## Generated with https://github.com/google/shaka-packager version "
       "test\n"
       "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"audiogroup\",NAME=\"english\","
-      "URI=\"http://playlists.org/eng.m3u8\"\n"
+      "LANGUAGE=\"en\",URI=\"http://playlists.org/eng.m3u8\"\n"
       "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"audiogroup\",NAME=\"espanol\","
-      "URI=\"http://playlists.org/spa.m3u8\"\n"
+      "LANGUAGE=\"es\",URI=\"http://playlists.org/spa.m3u8\"\n"
       "#EXT-X-STREAM-INF:AUDIO=\"audiogroup\","
       "CODECS=\"sdvideocodec,audiocodec\","
       "BANDWIDTH=360000\n"
@@ -198,6 +200,7 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistMultipleAudioGroups) {
   std::string audio_codec_lo = "audiocodec_lo";
   MockMediaPlaylist eng_lo_playlist(kVodPlaylist, "eng_lo.m3u8", "english_lo",
                                     "audio_lo");
+  EXPECT_CALL(eng_lo_playlist, GetLanguage()).WillRepeatedly(Return("en"));
   eng_lo_playlist.SetStreamTypeForTesting(
       MediaPlaylist::MediaPlaylistStreamType::kPlayListAudio);
   eng_lo_playlist.SetCodecForTesting(audio_codec_lo);
@@ -209,6 +212,7 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistMultipleAudioGroups) {
   std::string audio_codec_hi = "audiocodec_hi";
   MockMediaPlaylist eng_hi_playlist(kVodPlaylist, "eng_hi.m3u8", "english_hi",
                                     "audio_hi");
+  EXPECT_CALL(eng_hi_playlist, GetLanguage()).WillRepeatedly(Return("en"));
   eng_hi_playlist.SetStreamTypeForTesting(
       MediaPlaylist::MediaPlaylistStreamType::kPlayListAudio);
   eng_hi_playlist.SetCodecForTesting(audio_codec_hi);
@@ -233,9 +237,9 @@ TEST_F(MasterPlaylistTest, WriteMasterPlaylistMultipleAudioGroups) {
       "## Generated with https://github.com/google/shaka-packager version "
       "test\n"
       "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"audio_hi\",NAME=\"english_hi\","
-      "URI=\"http://anydomain.com/eng_hi.m3u8\"\n"
+      "LANGUAGE=\"en\",URI=\"http://anydomain.com/eng_hi.m3u8\"\n"
       "#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID=\"audio_lo\",NAME=\"english_lo\","
-      "URI=\"http://anydomain.com/eng_lo.m3u8\"\n"
+      "LANGUAGE=\"en\",URI=\"http://anydomain.com/eng_lo.m3u8\"\n"
       "#EXT-X-STREAM-INF:AUDIO=\"audio_hi\","
       "CODECS=\"videocodec,audiocodec_hi\","
       "BANDWIDTH=400000\n"

packager/hls/base/media_playlist.cc

@@ -12,6 +12,7 @@
 
 #include "packager/base/logging.h"
 #include "packager/base/strings/stringprintf.h"
+#include "packager/media/base/language_utils.h"
 #include "packager/media/file/file.h"
 #include "packager/version/version.h"
 
@@ -344,5 +345,20 @@ bool MediaPlaylist::SetTargetDuration(uint32_t target_duration) {
   return true;
 }
 
+// Duplicated from MpdUtils because:
+// 1. MpdUtils header depends on libxml header, which is not in the deps here
+// 2. GetLanguage depends on MediaInfo from packager/mpd/
+// 3. Moving GetLanguage to LanguageUtils would create a a media => mpd dep.
+// TODO: fix this dependency situation and factor this out to a common location
+std::string MediaPlaylist::GetLanguage() const {
+  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();
+  }
+  return LanguageToShortestForm(lang);
+}
+
 }  // namespace hls
 }  // namespace shaka

packager/hls/base/media_playlist.h

@@ -149,6 +149,10 @@ class MediaPlaylist {
   /// @return true if set, false otherwise.
   virtual bool SetTargetDuration(uint32_t target_duration);
 
+  /// @return the language of the media, as an ISO language tag in its shortest
+  ///         form.  May be an empty string for video.
+  virtual std::string GetLanguage() const;
+
  private:
   // Mainly for MasterPlaylist to use these values.
   const std::string file_name_;

packager/hls/base/media_playlist_unittest.cc

@@ -352,5 +352,23 @@ TEST_F(MediaPlaylistTest, RemoveOldestSegment) {
   EXPECT_TRUE(media_playlist_.WriteToFile(&file));
 }
 
+TEST_F(MediaPlaylistTest, GetLanguage) {
+  MediaInfo media_info;
+  media_info.set_reference_time_scale(90000);
+
+  // Check conversions from long to short form.
+  media_info.mutable_audio_info()->set_language("eng");
+  ASSERT_TRUE(media_playlist_.SetMediaInfo(media_info));
+  EXPECT_EQ("en", media_playlist_.GetLanguage());  // short form
+
+  media_info.mutable_audio_info()->set_language("eng-US");
+  ASSERT_TRUE(media_playlist_.SetMediaInfo(media_info));
+  EXPECT_EQ("en-US", media_playlist_.GetLanguage());  // region preserved
+
+  media_info.mutable_audio_info()->set_language("apa");
+  ASSERT_TRUE(media_playlist_.SetMediaInfo(media_info));
+  EXPECT_EQ("apa", media_playlist_.GetLanguage());  // no short form exists
+}
+
 }  // namespace hls
 }  // namespace shaka

packager/hls/base/mock_media_playlist.h

@@ -40,6 +40,7 @@ class MockMediaPlaylist : public MediaPlaylist {
   MOCK_CONST_METHOD0(Bitrate, uint64_t());
   MOCK_CONST_METHOD0(GetLongestSegmentDuration, double());
   MOCK_METHOD1(SetTargetDuration, bool(uint32_t target_duration));
+  MOCK_CONST_METHOD0(GetLanguage, std::string());
 };
 
 }  // namespace hls

packager/media/base/language_utils.cc

@@ -4,7 +4,7 @@
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 
-#include "packager/mpd/base/language_utils.h"
+#include "packager/media/base/language_utils.h"
 
 #include "packager/base/logging.h"
 
@@ -87,6 +87,11 @@ void SplitLanguageTag(const std::string& tag,
 namespace shaka {
 
 std::string LanguageToShortestForm(const std::string& language) {
+  // Do not try to mangle blank strings.
+  if (language.size() == 0) {
+    return language;
+  }
+
   std::string main_language;
   std::string subtag;
   SplitLanguageTag(language, &main_language, &subtag);

packager/media/base/language_utils.h

@@ -6,16 +6,19 @@
 //
 // Funtions used by MpdBuilder class to generate an MPD file.
 
-#ifndef MPD_BASE_LANGUAGE_UTILS_H_
-#define MPD_BASE_LANGUAGE_UTILS_H_
+#ifndef MEDIA_BASE_LANGUAGE_UTILS_H_
+#define MEDIA_BASE_LANGUAGE_UTILS_H_
 
 #include <string>
 
 namespace shaka {
 
+class MediaInfo;
+
 /// Convert a language tag to its shortest form, as required by RFC 5646
-/// indicated in the MPD spec.  Assumes the input is a valid ISO-639-2 or
-/// ISO-639-1 language tag.  Regions and variants are not supported.
+/// indicated in the MPD and HLS specs.  Assumes the input is a valid ISO-639-2
+/// or ISO-639-1 language tag, or an empty string.  Regions and variants are
+/// preserved in the conversion.
 std::string LanguageToShortestForm(const std::string& language);
 
 /// Convert a language tag to a 3-letter ISO-639-2 code, as required by the ISO
@@ -25,4 +28,4 @@ std::string LanguageToISO_639_2(const std::string& language);
 
 }  // namespace shaka
 
-#endif  // MPD_BASE_LANGUAGE_UTILS_H_
+#endif  // MEDIA_BASE_LANGUAGE_UTILS_H_

packager/media/base/media_base.gyp

@@ -52,6 +52,8 @@
         'key_fetcher.h',
         'key_source.cc',
         'key_source.h',
+        'language_utils.cc',
+        'language_utils.h',
         'limits.h',
         'macros.h',
         'media_handler.cc',

packager/mpd/base/mpd_builder.cc

@@ -24,9 +24,9 @@
 #include "packager/base/synchronization/lock.h"
 #include "packager/base/time/default_clock.h"
 #include "packager/base/time/time.h"
+#include "packager/media/base/language_utils.h"
 #include "packager/media/file/file.h"
 #include "packager/mpd/base/content_protection_element.h"
-#include "packager/mpd/base/language_utils.h"
 #include "packager/mpd/base/mpd_utils.h"
 #include "packager/mpd/base/xml/xml_node.h"
 #include "packager/version/version.h"

packager/mpd/mpd.gyp

@@ -39,8 +39,6 @@
         'base/content_protection_element.h',
         'base/dash_iop_mpd_notifier.cc',
         'base/dash_iop_mpd_notifier.h',
-        'base/language_utils.cc',
-        'base/language_utils.h',
         'base/mpd_builder.cc',
         'base/mpd_builder.h',
         'base/mpd_notifier_util.cc',