Make HLS with key rotation work

- Remove the TS key rotation not supported check as there is nothing
  to be done for key rotation in TS for SAMPLE-AES.
- Fix IV updated problem in new segments even if crypto period does
  not change.
- Avoid duplicate EXT-X-KEY tags if it does not change.
- Make EXT-X-DISCONTINUITY-SEQUENCE match with number of removed
  EXT-X-DISCONTINUITY.
- Added end to end test for HLS with key rotation.

Change-Id: I73cb82e9f5575fcdf63ee643228efe78e6766302

packager/app/test/packager_test.py

@@ -461,6 +461,34 @@ class PackagerFunctionalTest(PackagerAppTest):
         os.path.join(self.tmp_dir, 'video.m3u8'),
         'bear-640x360-v-live-golden.m3u8')
 
+  def testPackageAvcTsLivePlaylistWithKeyRotation(self):
+    self.packager.Package(
+        self._GetStreams(
+            ['audio', 'video'],
+            output_format='ts',
+            live=True,
+            test_files=['bear-640x360.ts']),
+        self._GetFlags(
+            encryption=True,
+            key_rotation=True,
+            output_hls=True,
+            hls_playlist_type='LIVE',
+            time_shift_buffer_depth=0.5))
+    self._DiffLiveGold(self.output[0],
+                       'bear-640x360-a-enc-rotation-golden',
+                       output_format='ts')
+    self._DiffLiveGold(self.output[1],
+                       'bear-640x360-v-enc-rotation-golden',
+                       output_format='ts')
+    self._DiffGold(self.hls_master_playlist_output,
+                   'bear-640x360-av-master-golden.m3u8')
+    self._DiffGold(
+        os.path.join(self.tmp_dir, 'audio.m3u8'),
+        'bear-640x360-a-live-enc-rotation-golden.m3u8')
+    self._DiffGold(
+        os.path.join(self.tmp_dir, 'video.m3u8'),
+        'bear-640x360-v-live-enc-rotation-golden.m3u8')
+
   def testPackageAvcTsEventPlaylist(self):
     self.assertPackageSuccess(
         self._GetStreams(
@@ -664,7 +692,7 @@ class PackagerFunctionalTest(PackagerAppTest):
                        'bear-640x360-v-enc-golden',
                        output_format='ts')
     self._DiffGold(self.hls_master_playlist_output,
-                   'bear-640x360-av-enc-master-golden.m3u8')
+                   'bear-640x360-av-master-golden.m3u8')
     self._DiffGold(
         os.path.join(self.tmp_dir, 'audio.m3u8'),
         'bear-640x360-a-enc-golden.m3u8')

packager/app/test/testdata/bear-640x360-a-live-enc-rotation-golden.m3u8

@@ -0,0 +1,11 @@
+#EXTM3U
+#EXT-X-VERSION:6
+## Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>
+#EXT-X-TARGETDURATION:2
+#EXT-X-MEDIA-SEQUENCE:1
+#EXTINF:0.998,
+output_audio-2.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MzQ1Njc4OTAxMjM0NTYxMg==",IV=0x3334353637383930,KEYFORMAT="identity"
+#EXTINF:0.789,
+output_audio-3.ts

packager/app/test/testdata/bear-640x360-av-enc-master-golden.m3u8

@@ -1,5 +0,0 @@
-#EXTM3U
-## Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>
-#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="stream_0",URI="audio.m3u8"
-#EXT-X-STREAM-INF:BANDWIDTH=1217518,CODECS="avc1.64001e,mp4a.40.2",RESOLUTION=640x360,AUDIO="audio"
-video.m3u8

packager/app/test/testdata/bear-640x360-v-live-enc-rotation-golden.m3u8

@@ -0,0 +1,12 @@
+#EXTM3U
+#EXT-X-VERSION:6
+## Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>
+#EXT-X-TARGETDURATION:2
+#EXT-X-MEDIA-SEQUENCE:1
+#EXT-X-DISCONTINUITY-SEQUENCE:1
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MjM0NTY3ODkwMTIzNDU2MQ==",IV=0x3334353637383930,KEYFORMAT="identity"
+#EXTINF:1.001,
+output_video-2.ts
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MzQ1Njc4OTAxMjM0NTYxMg==",IV=0x3334353637383930,KEYFORMAT="identity"
+#EXTINF:0.734,
+output_video-3.ts

packager/hls/base/media_playlist.cc

@@ -36,7 +36,7 @@ uint32_t GetTimeScale(const MediaInfo& media_info) {
 std::string CreatePlaylistHeader(const std::string& init_segment_name,
                                  uint32_t target_duration,
                                  MediaPlaylist::MediaPlaylistType type,
-                                 int sequence_number,
+                                 int media_sequence_number,
                                  int discontinuity_sequence_number) {
   const std::string version = GetPackagerVersion();
   std::string version_line;
@@ -62,9 +62,9 @@ std::string CreatePlaylistHeader(const std::string& init_segment_name,
       header += "#EXT-X-PLAYLIST-TYPE:EVENT\n";
       break;
     case MediaPlaylist::MediaPlaylistType::kLive:
-      if (sequence_number > 0) {
+      if (media_sequence_number > 0) {
         base::StringAppendF(&header, "#EXT-X-MEDIA-SEQUENCE:%d\n",
-                            sequence_number);
+                            media_sequence_number);
       }
       if (discontinuity_sequence_number > 0) {
         base::StringAppendF(&header, "#EXT-X-DISCONTINUITY-SEQUENCE:%d\n",
@@ -186,6 +186,27 @@ std::string EncryptionInfoEntry::ToString() {
   return ext_key + ",KEYFORMAT=\"" + key_format_ + "\"\n";
 }
 
+class DiscontinuityEntry : public HlsEntry {
+ public:
+  DiscontinuityEntry();
+
+  ~DiscontinuityEntry() override;
+
+  std::string ToString() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DiscontinuityEntry);
+};
+
+DiscontinuityEntry::DiscontinuityEntry()
+    : HlsEntry(HlsEntry::EntryType::kExtDiscontinuity) {}
+
+DiscontinuityEntry::~DiscontinuityEntry() {}
+
+std::string DiscontinuityEntry::ToString() {
+  return "#EXT-X-DISCONTINUITY\n";
+}
+
 double LatestSegmentStartTime(
     const std::list<std::unique_ptr<HlsEntry>>& entries) {
   DCHECK(!entries.empty());
@@ -276,69 +297,19 @@ void MediaPlaylist::AddSegment(const std::string& file_name,
   SlideWindow();
 }
 
-// TODO(rkuroiwa): This works for single key format but won't work for multiple
-// key formats (e.g. different DRM systems).
-// Candidate algorithm:
-// Assume entries_ is std::list (static_assert below).
-// Create a map from key_format to EncryptionInfoEntry (iterator actually).
-// Iterate over entries_ until it hits SegmentInfoEntry. While iterating over
-// entries_ if there are multiple EncryptionInfoEntry with the same key_format,
-// erase the older ones using the iterator.
-// Note that when erasing std::list iterators, only the deleted iterators are
-// invalidated.
-void MediaPlaylist::RemoveOldestSegment() {
-  static_assert(std::is_same<decltype(entries_),
-                             std::list<std::unique_ptr<HlsEntry>>>::value,
-                "This algorithm assumes std::list.");
-  if (entries_.empty())
-    return;
-  if (entries_.front()->type() == HlsEntry::EntryType::kExtInf) {
-    entries_.pop_front();
-    return;
-  }
-
-  // Make sure that the first EXT-X-KEY entry doesn't get popped out until the
-  // next EXT-X-KEY entry because the first EXT-X-KEY applies to all the
-  // segments following until the next one.
-
-  if (entries_.size() == 1) {
-    // More segments might get added, leave the entry in.
-    return;
-  }
-
-  if (entries_.size() == 2) {
-    auto entries_itr = entries_.begin();
-    ++entries_itr;
-    if ((*entries_itr)->type() == HlsEntry::EntryType::kExtKey) {
-      entries_.pop_front();
-    } else {
-      entries_.erase(entries_itr);
-    }
-    return;
-  }
-
-  auto entries_itr = entries_.begin();
-  ++entries_itr;
-  if ((*entries_itr)->type() == HlsEntry::EntryType::kExtInf) {
-    DCHECK((*entries_itr)->type() == HlsEntry::EntryType::kExtInf);
-    entries_.erase(entries_itr);
-    return;
-  }
-
-  ++entries_itr;
-  // This assumes that there is a segment between 2 EXT-X-KEY entries.
-  // Which should be the case due to logic in AddEncryptionInfo().
-  DCHECK((*entries_itr)->type() == HlsEntry::EntryType::kExtInf);
-  entries_.erase(entries_itr);
-  entries_.pop_front();
-}
-
 void MediaPlaylist::AddEncryptionInfo(MediaPlaylist::EncryptionMethod method,
                                       const std::string& url,
                                       const std::string& key_id,
                                       const std::string& iv,
                                       const std::string& key_format,
                                       const std::string& key_format_versions) {
+  if (!inserted_discontinuity_tag_) {
+    // Insert discontinuity tag only for the first EXT-X-KEY, only if there
+    // are non-encrypted media segments.
+    if (!entries_.empty())
+      entries_.emplace_back(new DiscontinuityEntry());
+    inserted_discontinuity_tag_ = true;
+  }
   entries_.emplace_back(new EncryptionInfoEntry(
       method, url, key_id, iv, key_format, key_format_versions));
 }
@@ -350,22 +321,11 @@ bool MediaPlaylist::WriteToFile(const std::string& file_path) {
 
   std::string header = CreatePlaylistHeader(
       media_info_.init_segment_name(), target_duration_, type_,
-      sequence_number_, discontinuity_sequence_number_);
+      media_sequence_number_, discontinuity_sequence_number_);
 
   std::string body;
-  if (!entries_.empty()) {
+  for (const auto& entry : entries_)
-    const bool first_is_ext_key =
-        entries_.front()->type() == HlsEntry::EntryType::kExtKey;
-    bool inserted_discontinuity_tag = false;
-    for (const auto& entry : entries_) {
-      if (!first_is_ext_key && !inserted_discontinuity_tag &&
-          entry->type() == HlsEntry::EntryType::kExtKey) {
-        body.append("#EXT-X-DISCONTINUITY\n");
-        inserted_discontinuity_tag = true;
-      }
     body.append(entry->ToString());
-    }
-  }
 
   std::string content = header + body;
 
@@ -475,18 +435,11 @@ void MediaPlaylist::SlideWindow() {
   for (; last != entries_.end(); ++last) {
     HlsEntry::EntryType entry_type = last->get()->type();
     if (entry_type == HlsEntry::EntryType::kExtKey) {
-      if (prev_entry_type != HlsEntry::EntryType::kExtKey) {
+      if (prev_entry_type != HlsEntry::EntryType::kExtKey)
-        if (!ext_x_keys.empty()) {
-          // Increase discontinuity sequence every time key changes. Note that
-          // it is inconsistent to how we insert EXT-X-DISCONTINUITY tag
-          // currently as we only insert the tag for the first EXT-X-KEY.
-          // TODO(kqyang): Find out if it is necessary to insert the
-          // EXT-X-DISCONTINUITY tag when key changes.
-          ++discontinuity_sequence_number_;
         ext_x_keys.clear();
-        }
-      }
       ext_x_keys.push_back(std::move(*last));
+    } else if (entry_type == HlsEntry::EntryType::kExtDiscontinuity) {
+      ++discontinuity_sequence_number_;
     } else {
       DCHECK_EQ(entry_type, HlsEntry::EntryType::kExtInf);
       const SegmentInfoEntry* segment_info =
@@ -503,7 +456,7 @@ void MediaPlaylist::SlideWindow() {
   // Add key entries back.
   entries_.insert(entries_.begin(), std::make_move_iterator(ext_x_keys.begin()),
                   std::make_move_iterator(ext_x_keys.end()));
-  sequence_number_ += num_segments_removed;
+  media_sequence_number_ += num_segments_removed;
 }
 
 }  // namespace hls

packager/hls/base/media_playlist.h

@@ -27,6 +27,7 @@ class HlsEntry {
   enum class EntryType {
     kExtInf,
     kExtKey,
+    kExtDiscontinuity,
   };
   virtual ~HlsEntry();
 
@@ -105,10 +106,6 @@ class MediaPlaylist {
                           uint64_t duration,
                           uint64_t size);
 
-  /// Removes the oldest segment from the playlist. Useful for manually managing
-  /// the length of the playlist.
-  virtual void RemoveOldestSegment();
-
   /// All segments added after calling this method must be decryptable with
   /// the key that can be fetched from |url|, until calling this again.
   /// @param method is the encryption method.
@@ -180,7 +177,8 @@ class MediaPlaylist {
   MediaPlaylistStreamType stream_type_ =
       MediaPlaylistStreamType::kPlaylistUnknown;
   std::string codec_;
-  int sequence_number_ = 0;
+  int media_sequence_number_ = 0;
+  bool inserted_discontinuity_tag_ = false;
   int discontinuity_sequence_number_ = 0;
 
   double longest_segment_duration_ = 0.0;

packager/hls/base/media_playlist_unittest.cc

@@ -274,31 +274,6 @@ TEST_F(MediaPlaylistTest, WriteToFileWithClearLead) {
   ASSERT_FILE_STREQ(kMemoryFilePath, kExpectedOutput);
 }
 
-
-TEST_F(MediaPlaylistTest, RemoveOldestSegment) {
-  ASSERT_TRUE(media_playlist_.SetMediaInfo(valid_video_media_info_));
-
-  media_playlist_.AddSegment("file1.ts", 0, 10 * kTimeScale, kMBytes);
-  media_playlist_.AddSegment("file2.ts", 10 * kTimeScale, 30 * kTimeScale,
-                             5 * kMBytes);
-  media_playlist_.RemoveOldestSegment();
-
-  const char kExpectedOutput[] =
-      "#EXTM3U\n"
-      "#EXT-X-VERSION:6\n"
-      "## Generated with https://github.com/google/shaka-packager version "
-      "test\n"
-      "#EXT-X-TARGETDURATION:30\n"
-      "#EXT-X-PLAYLIST-TYPE:VOD\n"
-      "#EXTINF:30.000,\n"
-      "file2.ts\n"
-      "#EXT-X-ENDLIST\n";
-
-  const char kMemoryFilePath[] = "memory://media.m3u8";
-  EXPECT_TRUE(media_playlist_.WriteToFile(kMemoryFilePath));
-  ASSERT_FILE_STREQ(kMemoryFilePath, kExpectedOutput);
-}
-
 TEST_F(MediaPlaylistTest, GetLanguage) {
   MediaInfo media_info;
   media_info.set_reference_time_scale(kTimeScale);
@@ -510,6 +485,8 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfo) {
 TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
   ASSERT_TRUE(media_playlist_.SetMediaInfo(valid_video_media_info_));
 
+  media_playlist_.AddSegment("file1.ts", 0, 10 * kTimeScale, kMBytes);
+
   media_playlist_.AddEncryptionInfo(MediaPlaylist::EncryptionMethod::kSampleAes,
                                     "http://example.com", "", "0x12345678",
                                     "com.widevine", "1/2/4");
@@ -517,7 +494,8 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       MediaPlaylist::EncryptionMethod::kSampleAes, "http://mydomain.com",
       "0xfedc", "0x12345678", "com.widevine.someother", "1");
 
-  media_playlist_.AddSegment("file1.ts", 0, 10 * kTimeScale, kMBytes);
+  media_playlist_.AddSegment("file2.ts", 10 * kTimeScale, 20 * kTimeScale,
+                             2 * kMBytes);
 
   media_playlist_.AddEncryptionInfo(MediaPlaylist::EncryptionMethod::kSampleAes,
                                     "http://example.com", "", "0x22345678",
@@ -526,7 +504,7 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       MediaPlaylist::EncryptionMethod::kSampleAes, "http://mydomain.com",
       "0xfedd", "0x22345678", "com.widevine.someother", "1");
 
-  media_playlist_.AddSegment("file2.ts", 10 * kTimeScale, 20 * kTimeScale,
+  media_playlist_.AddSegment("file3.ts", 30 * kTimeScale, 20 * kTimeScale,
                              2 * kMBytes);
 
   media_playlist_.AddEncryptionInfo(MediaPlaylist::EncryptionMethod::kSampleAes,
@@ -536,7 +514,7 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       MediaPlaylist::EncryptionMethod::kSampleAes, "http://mydomain.com",
       "0xfede", "0x32345678", "com.widevine.someother", "1");
 
-  media_playlist_.AddSegment("file3.ts", 30 * kTimeScale, 20 * kTimeScale,
+  media_playlist_.AddSegment("file4.ts", 50 * kTimeScale, 20 * kTimeScale,
                              2 * kMBytes);
   const char kExpectedOutput[] =
       "#EXTM3U\n"
@@ -544,7 +522,7 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       "## Generated with https://github.com/google/shaka-packager version "
       "test\n"
       "#EXT-X-TARGETDURATION:20\n"
-      "#EXT-X-MEDIA-SEQUENCE:1\n"
+      "#EXT-X-MEDIA-SEQUENCE:2\n"
       "#EXT-X-DISCONTINUITY-SEQUENCE:1\n"
       "#EXT-X-KEY:METHOD=SAMPLE-AES,"
       "URI=\"http://example.com\",IV=0x22345678,KEYFORMATVERSIONS=\"1/2/4\","
@@ -554,7 +532,7 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       "KEYFORMATVERSIONS=\"1\","
       "KEYFORMAT=\"com.widevine.someother\"\n"
       "#EXTINF:20.000,\n"
-      "file2.ts\n"
+      "file3.ts\n"
       "#EXT-X-KEY:METHOD=SAMPLE-AES,"
       "URI=\"http://example.com\",IV=0x32345678,KEYFORMATVERSIONS=\"1/2/4\","
       "KEYFORMAT=\"com.widevine\"\n"
@@ -563,7 +541,7 @@ TEST_F(LiveMediaPlaylistTest, TimeShiftedWithEncryptionInfoShifted) {
       "KEYFORMATVERSIONS=\"1\","
       "KEYFORMAT=\"com.widevine.someother\"\n"
       "#EXTINF:20.000,\n"
-      "file3.ts\n";
+      "file4.ts\n";
 
   const char kMemoryFilePath[] = "memory://media.m3u8";
   EXPECT_TRUE(media_playlist_.WriteToFile(kMemoryFilePath));

packager/media/base/muxer.cc

@@ -46,20 +46,23 @@ Status Muxer::Process(std::unique_ptr<StreamData> stream_data) {
             kInitialEncryptionInfo, encryption_config.protection_scheme,
             encryption_config.key_id, encryption_config.constant_iv,
             encryption_config.key_system_info);
+        current_key_id_ = encryption_config.key_id;
       }
       return InitializeMuxer();
     case StreamDataType::kSegmentInfo: {
       auto& segment_info = stream_data->segment_info;
-      if (muxer_listener_) {
+      if (muxer_listener_ && segment_info->is_encrypted) {
         const EncryptionConfig* encryption_config =
             segment_info->key_rotation_encryption_config.get();
-        if (encryption_config) {
+        // Only call OnEncryptionInfoReady again when key updates.
+        if (encryption_config && encryption_config->key_id != current_key_id_) {
           muxer_listener_->OnEncryptionInfoReady(
               !kInitialEncryptionInfo, encryption_config->protection_scheme,
               encryption_config->key_id, encryption_config->constant_iv,
               encryption_config->key_system_info);
+          current_key_id_ = encryption_config->key_id;
         }
-        if (segment_info->is_encrypted && !encryption_started_) {
+        if (!encryption_started_) {
           encryption_started_ = true;
           muxer_listener_->OnEncryptionStart();
         }

packager/media/base/muxer.h

@@ -88,6 +88,7 @@ class Muxer : public MediaHandler {
 
   MuxerOptions options_;
   std::vector<std::shared_ptr<StreamInfo>> streams_;
+  std::vector<uint8_t> current_key_id_;
   bool encryption_started_ = false;
   bool cancelled_;
 

packager/media/crypto/encryption_handler.cc

@@ -222,6 +222,7 @@ Status EncryptionHandler::ProcessMediaSample(MediaSample* sample) {
         return status;
       if (!CreateEncryptor(encryption_key))
         return Status(error::ENCRYPTION_FAILURE, "Failed to create encryptor");
+      prev_crypto_period_index_ = current_crypto_period_index;
     }
     check_new_crypto_period_ = false;
   }

packager/media/crypto/encryption_handler_unittest.cc

@@ -304,7 +304,8 @@ class EncryptionHandlerEncryptionTest
         } else {
           EXPECT_CALL(*mock_header_parser, GetHeaderSize(_))
               .WillOnce(Return(kSliceHeaderSize1))
-              .WillOnce(Return(kSliceHeaderSize2));
+              .WillOnce(Return(kSliceHeaderSize2))
+              .WillRepeatedly(Return(kSliceHeaderSize2));
         }
         InjectVideoSliceHeaderParserForTesting(std::move(mock_header_parser));
         break;
@@ -519,7 +520,9 @@ TEST_P(EncryptionHandlerEncryptionTest, ClearLeadWithNoKeyRotation) {
 
 TEST_P(EncryptionHandlerEncryptionTest, ClearLeadWithKeyRotation) {
   const double kClearLeadInSeconds = 1.5 * kSegmentDuration / kTimeScale;
-  const double kCryptoPeriodDurationInSeconds = kSegmentDuration / kTimeScale;
+  const int kSegmentsPerCryptoPeriod = 2;  // 2 segments.
+  const double kCryptoPeriodDurationInSeconds =
+      kSegmentsPerCryptoPeriod * kSegmentDuration / kTimeScale;
   EncryptionOptions encryption_options;
   encryption_options.protection_scheme = protection_scheme_;
   encryption_options.clear_lead_in_seconds = kClearLeadInSeconds;
@@ -546,19 +549,20 @@ TEST_P(EncryptionHandlerEncryptionTest, ClearLeadWithKeyRotation) {
 
   InjectCodecParser();
 
-  // There are three segments. Only the third segment is encrypted.
+  // There are five segments with the first two not encrypted.
-  // Crypto period duration is the same as segment duration, so there are three
+  for (int i = 0; i < 5; ++i) {
-  // crypto periods, although only the last is encrypted.
+    if ((i % kSegmentsPerCryptoPeriod) == 0) {
-  for (int i = 0; i < 3; ++i) {
+      EXPECT_CALL(mock_key_source_,
-    EXPECT_CALL(mock_key_source_, GetCryptoPeriodKey(i, _, _))
+                  GetCryptoPeriodKey(i / kSegmentsPerCryptoPeriod, _, _))
           .WillOnce(DoAll(SetArgPointee<2>(GetMockEncryptionKey()),
                           Return(Status::OK)));
+    }
     // Use single-frame segment for testing.
     ASSERT_OK(Process(GetMediaSampleStreamData(
         kStreamIndex, i * kSegmentDuration, kSegmentDuration)));
     ASSERT_OK(Process(GetSegmentInfoStreamData(
         kStreamIndex, i * kSegmentDuration, kSegmentDuration, !kIsSubsegment)));
-    const bool is_encrypted = i == 2;
+    const bool is_encrypted = i >= 2;
     const auto& output_stream_data = GetOutputStreamDataVector();
     EXPECT_THAT(output_stream_data,
                 ElementsAre(IsMediaSample(kStreamIndex, i * kSegmentDuration,

packager/media/event/hls_notify_muxer_listener.cc

@@ -33,12 +33,9 @@ HlsNotifyMuxerListener::~HlsNotifyMuxerListener() {}
 // These methods work together to notify that the media is encrypted.
 // If OnEncryptionInfoReady() is called before the media has been started, then
 // the information is stored and handled when OnEncryptionStart() is called.
-// if OnEncryptionStart() is called before the media has been started then
+// If OnEncryptionStart() is called before the media has been started then
 // OnMediaStart() is responsible for notifying that the segments are encrypted
 // right away i.e. call OnEncryptionStart().
-// For now (because Live HLS is not implemented yet) this should be called once,
-// before media is started. So the logic after the first if statement should not
-// be taken.
 void HlsNotifyMuxerListener::OnEncryptionInfoReady(
     bool is_initial_encryption_info,
     FourCC protection_scheme,

packager/media/event/muxer_listener.h

@@ -38,15 +38,14 @@ class MuxerListener {
 
   virtual ~MuxerListener() {};
 
-  /// Called when the media's encryption information is ready. This should be
+  /// Called when the media's encryption information is ready.
-  /// called before OnMediaStart(), if the media is encrypted.
+  /// OnEncryptionInfoReady with @a initial_encryption_info being true should be
-  /// All the parameters may be empty just to notify that the media is
+  /// called before OnMediaStart(), if the media is encrypted. All the
-  /// encrypted.
+  /// parameters may be empty just to notify that the media is encrypted. For
-  /// For ISO BMFF (MP4) media:
+  /// ISO BMFF (MP4) media: If @a is_initial_encryption_info is true then @a
-  /// If @a is_initial_encryption_info is true then @a key_id is the default_KID
+  /// key_id is the default_KID in 'tenc' box. If @a is_initial_encryption_info
-  /// in 'tenc' box.
+  /// is false then @a key_id is the new key ID for the for the next crypto
-  /// If @a is_initial_encryption_info is false then @a key_id is the new key ID
+  /// period.
-  /// for the for the next crypto period.
   /// @param is_initial_encryption_info is true if this is the first encryption
   ///        info for the media. In general, this flag should always be true for
   ///        non-key-rotated media and should be called only once.

packager/media/formats/mp2t/ts_muxer.cc

@@ -41,11 +41,6 @@ Status TsMuxer::AddSample(size_t stream_id,
 Status TsMuxer::FinalizeSegment(size_t stream_id,
                                 std::shared_ptr<SegmentInfo> segment_info) {
   DCHECK_EQ(stream_id, 0u);
-  if (segment_info->key_rotation_encryption_config) {
-    NOTIMPLEMENTED() << "Key rotation is not implemented for TS.";
-    return Status(error::UNIMPLEMENTED,
-                  "Key rotation is not implemented for TS");
-  }
   return segment_info->is_subsegment
              ? Status::OK
              : segmenter_->FinalizeSegment(segment_info->start_timestamp,