[HLS] Fixing AdCues handling in iframe playlists

Previously for the last iframe in a segment, we wait for the next
segment to arrive before writing the EXTINF tag. If an Ad Cue comes
in before the next segment, the EXT-X-PLACEMENT_OPPORTUNITY tag would
be inserted before the iframe in previous segment.

Fixes #378, #396.

Change-Id: I1ede72a4d4edca94781c7b05bc25397d67916d1a

packager/app/test/testdata/avc-ac3-ts-with-encryption/bear-640x360-ac3-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-ac3-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-ac3-video-2.ts

packager/app/test/testdata/avc-ts-aac-packed-audio-with-encryption/bear-640x360-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts

packager/app/test/testdata/avc-ts-ac3-packed-audio-with-encryption/bear-640x360-ac3-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-ac3-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-ac3-video-2.ts

packager/app/test/testdata/avc-ts-event-playlist/bear-640x360-video-iframe.m3u8

@@ -10,3 +10,6 @@ bear-640x360-video-1.ts
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts
+#EXTINF:0.667,
+#EXT-X-BYTERANGE:19928@376
+bear-640x360-video-3.ts

packager/app/test/testdata/avc-ts-event-playlist/output.m3u8

@@ -6,4 +6,4 @@
 #EXT-X-STREAM-INF:BANDWIDTH=1217518,CODECS="avc1.64001e,mp4a.40.2",RESOLUTION=640x360,AUDIO="default-audio-group"
 bear-640x360-video.m3u8
 
-#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=145742,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"
+#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=238897,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"

packager/app/test/testdata/avc-ts-live-playlist-with-key-rotation/bear-640x360-video-iframe.m3u8

@@ -2,12 +2,14 @@
 #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-I-FRAMES-ONLY
 #EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MjM0NTY3ODkwMTIzNDU2MQ==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
-#EXT-X-BYTERANGE:15604@376
-bear-640x360-video-1.ts
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MzQ1Njc4OTAxMjM0NTYxMg==",IV=0x3334353637383930,KEYFORMAT="identity"
-#EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MzQ1Njc4OTAxMjM0NTYxMg==",IV=0x3334353637383930,KEYFORMAT="identity"
+#EXTINF:0.667,
+#EXT-X-BYTERANGE:19928@376
+bear-640x360-video-3.ts

packager/app/test/testdata/avc-ts-live-playlist-with-key-rotation/output.m3u8

@@ -6,4 +6,4 @@
 #EXT-X-STREAM-INF:BANDWIDTH=1217518,CODECS="avc1.64001e,mp4a.40.2",RESOLUTION=640x360,AUDIO="default-audio-group"
 bear-640x360-video.m3u8
 
-#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=145742,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"
+#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=238897,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"

packager/app/test/testdata/avc-ts-live-playlist/bear-640x360-video-iframe.m3u8

@@ -2,10 +2,11 @@
 #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-I-FRAMES-ONLY
 #EXTINF:1.001,
-#EXT-X-BYTERANGE:15604@376
-bear-640x360-video-1.ts
-#EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts
+#EXTINF:0.667,
+#EXT-X-BYTERANGE:19928@376
+bear-640x360-video-3.ts

packager/app/test/testdata/avc-ts-live-playlist/output.m3u8

@@ -6,4 +6,4 @@
 #EXT-X-STREAM-INF:BANDWIDTH=1217518,CODECS="avc1.64001e,mp4a.40.2",RESOLUTION=640x360,AUDIO="default-audio-group"
 bear-640x360-video.m3u8
 
-#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=145742,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"
+#EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=238897,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-video-iframe.m3u8"

packager/app/test/testdata/avc-ts-with-encryption-and-fairplay/bear-640x360-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="skd://www.license.com/getkey?KeyId=31323334-3536-3738-3930-313233343536",KEYFORMATVERSIONS="1",KEYFORMAT="com.apple.streamingkeydelivery"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="skd://www.license.com/getkey?KeyId=31323334-3536-3738-3930-313233343536",KEYFORMATVERSIONS="1",KEYFORMAT="com.apple.streamingkeydelivery"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts

packager/app/test/testdata/avc-ts-with-encryption-exercise-emulation-prevention/sintel-1024x436-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.000,
 #EXT-X-BYTERANGE:940@376
 sintel-1024x436-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.000,
 #EXT-X-BYTERANGE:376@376
 sintel-1024x436-video-2.ts

packager/app/test/testdata/avc-ts-with-encryption/bear-640x360-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-video-2.ts

packager/app/test/testdata/ec3-packed-audio-encrypted/bear-640x360-ec3-video-iframe.m3u8

@@ -4,10 +4,11 @@
 #EXT-X-TARGETDURATION:2
 #EXT-X-PLAYLIST-TYPE:VOD
 #EXT-X-I-FRAMES-ONLY
-#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15604@376
 bear-640x360-ec3-video-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=SAMPLE-AES,URI="data:text/plain;base64,MTIzNDU2Nzg5MDEyMzQ1Ng==",IV=0x3334353637383930,KEYFORMAT="identity"
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18236@376
 bear-640x360-ec3-video-2.ts

packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-640x360-video-iframe.m3u8

@@ -8,10 +8,10 @@
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15581@80
 bear-640x360-video-1.m4s
-#EXT-X-PLACEMENT-OPPORTUNITY
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18221@80
 bear-640x360-video-2.m4s
+#EXT-X-PLACEMENT-OPPORTUNITY
 #EXTINF:0.734,
 #EXT-X-BYTERANGE:19663@80
 bear-640x360-video-3.m4s

packager/app/test/testdata/hls-single-segment-mp4-encrypted-and-ad-cues/bear-640x360-video-iframe.m3u8

@@ -9,10 +9,10 @@
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:15581@1159
 bear-640x360-video.mp4
-#EXT-X-PLACEMENT-OPPORTUNITY
 #EXTINF:1.001,
 #EXT-X-BYTERANGE:18754@100472
 bear-640x360-video.mp4
+#EXT-X-PLACEMENT-OPPORTUNITY
 #EXTINF:0.734,
 #EXT-X-BYTERANGE:20068@222812
 bear-640x360-video.mp4

packager/hls/base/media_playlist.cc

@@ -151,14 +151,15 @@ class SegmentInfoEntry : public HlsEntry {
   std::string ToString() override;
   double start_time() const { return start_time_; }
   double duration() const { return duration_; }
+  void set_duration(double duration) { duration_ = duration; }
 
  private:
   SegmentInfoEntry(const SegmentInfoEntry&) = delete;
   SegmentInfoEntry& operator=(const SegmentInfoEntry&) = delete;
 
   const std::string file_name_;
   const double start_time_;
-  const double duration_;
+  double duration_;
   const bool use_byte_range_;
   const uint64_t start_byte_offset_;
   const uint64_t segment_file_size_;
@@ -379,20 +380,20 @@ void MediaPlaylist::AddSegment(const std::string& file_name,
   if (stream_type_ == MediaPlaylistStreamType::kVideoIFramesOnly) {
     if (key_frames_.empty())
       return;
-    // Skip the last entry as the duration of the key frames are defined by the
-    // next key frame, which we don't know yet.
-    for (auto iter = key_frames_.begin(); iter != std::prev(key_frames_.end());
-         ++iter) {
-      const std::string& segment_file_name =
-          iter->segment_file_name.empty() ? file_name : iter->segment_file_name;
-      AddSegmentInfoEntry(segment_file_name, iter->timestamp, iter->duration,
+
+    AdjustLastSegmentInfoEntryDuration(key_frames_.front().timestamp);
+
+    for (auto iter = key_frames_.begin(); iter != key_frames_.end(); ++iter) {
+      // Last entry duration may be adjusted later when the next iframe becomes
+      // available.
+      const uint64_t next_timestamp = std::next(iter) == key_frames_.end()
+                                          ? (start_time + duration)
+                                          : std::next(iter)->timestamp;
+      AddSegmentInfoEntry(file_name, iter->timestamp,
+                          next_timestamp - iter->timestamp,
                           iter->start_byte_offset, iter->size);
     }
-
-    key_frames_.erase(key_frames_.begin(), std::prev(key_frames_.end()));
-    KeyFrameInfo& key_frame = key_frames_.front();
-    key_frame.segment_file_name = file_name;
-    key_frame.duration = start_time + duration - key_frame.timestamp;
+    key_frames_.clear();
     return;
   }
   return AddSegmentInfoEntry(file_name, start_time, duration, start_byte_offset,
@@ -411,9 +412,6 @@ void MediaPlaylist::AddKeyFrame(uint64_t timestamp,
     stream_type_ = MediaPlaylistStreamType::kVideoIFramesOnly;
     use_byte_range_ = true;
   }
-  if (!key_frames_.empty()) {
-    key_frames_.back().duration = timestamp - key_frames_.back().timestamp;
-  }
   key_frames_.push_back({timestamp, start_byte_offset, size});
 }
 
@@ -439,18 +437,6 @@ void MediaPlaylist::AddPlacementOpportunity() {
 }
 
 bool MediaPlaylist::WriteToFile(const std::string& file_path) {
-  if (!key_frames_.empty() &&
-      hls_params_.playlist_type == HlsPlaylistType::kVod) {
-    // Flush remaining key frames. This assumes |WriteToFile| is only called
-    // once at the end of the file in VOD.
-    CHECK_EQ(key_frames_.size(), 1u);
-    const KeyFrameInfo& key_frame = key_frames_.front();
-    AddSegmentInfoEntry(key_frame.segment_file_name, key_frame.timestamp,
-                        key_frame.duration, key_frame.start_byte_offset,
-                        key_frame.size);
-    key_frames_.clear();
-  }
-
   if (!target_duration_set_) {
     SetTargetDuration(ceil(GetLongestSegmentDuration()));
   }
@@ -548,6 +534,25 @@ void MediaPlaylist::AddSegmentInfoEntry(const std::string& segment_file_name,
   SlideWindow();
 }
 
+void MediaPlaylist::AdjustLastSegmentInfoEntryDuration(
+    uint64_t next_timestamp) {
+  if (time_scale_ == 0)
+    return;
+
+  const double scaled_next_timestamp =
+      static_cast<double>(next_timestamp) / time_scale_;
+
+  for (auto iter = entries_.rbegin(); iter != entries_.rend(); ++iter) {
+    if (iter->get()->type() == HlsEntry::EntryType::kExtInf) {
+      SegmentInfoEntry* segment_info =
+          reinterpret_cast<SegmentInfoEntry*>(iter->get());
+      segment_info->set_duration(scaled_next_timestamp -
+                                 segment_info->start_time());
+      break;
+    }
+  }
+}
+
 void MediaPlaylist::SlideWindow() {
   DCHECK(!entries_.empty());
   if (hls_params_.time_shift_buffer_depth <= 0.0 ||

packager/hls/base/media_playlist.h

@@ -185,6 +185,9 @@ class MediaPlaylist {
                            uint64_t duration,
                            uint64_t start_byte_offset,
                            uint64_t size);
+  // Adjust the duration of the last SegmentInfoEntry to end on
+  // |next_timestamp|.
+  void AdjustLastSegmentInfoEntryDuration(uint64_t next_timestamp);
   // Remove elements from |entries_| for live profile. Increments
   // |sequence_number_| by the number of segments removed.
   void SlideWindow();
@@ -231,7 +234,6 @@ class MediaPlaylist {
     uint64_t timestamp;
     uint64_t start_byte_offset;
     uint64_t size;
-    uint64_t duration;
     std::string segment_file_name;
   };
   std::list<KeyFrameInfo> key_frames_;

packager/hls/base/media_playlist_unittest.cc

@@ -811,7 +811,7 @@ TEST_F(IFrameMediaPlaylistTest, SingleSegment) {
       "#EXT-X-VERSION:6\n"
       "## Generated with https://github.com/google/shaka-packager version "
       "test\n"
-      "#EXT-X-TARGETDURATION:9\n"
+      "#EXT-X-TARGETDURATION:8\n"
       "#EXT-X-PLAYLIST-TYPE:VOD\n"
       "#EXT-X-I-FRAMES-ONLY\n"
       "#EXT-X-MAP:URI=\"file.mp4\",BYTERANGE=\"501@0\"\n"
@@ -875,6 +875,49 @@ TEST_F(IFrameMediaPlaylistTest, MultiSegment) {
   ASSERT_FILE_STREQ(kMemoryFilePath, kExpectedOutput);
 }
 
+TEST_F(IFrameMediaPlaylistTest, MultiSegmentWithPlacementOpportunity) {
+  valid_video_media_info_.set_reference_time_scale(90000);
+  valid_video_media_info_.set_segment_template_url("file$Number$.ts");
+  ASSERT_TRUE(media_playlist_->SetMediaInfo(valid_video_media_info_));
+
+  media_playlist_->AddKeyFrame(0, 1000, 2345);
+  media_playlist_->AddKeyFrame(2 * kTimeScale, 5000, 6345);
+  media_playlist_->AddSegment("file1.ts", 0, 10 * kTimeScale, kZeroByteOffset,
+                              kMBytes);
+  media_playlist_->AddPlacementOpportunity();
+  media_playlist_->AddKeyFrame(11 * kTimeScale, 1000, 2345);
+  media_playlist_->AddKeyFrame(15 * kTimeScale, 3345, 12345);
+  media_playlist_->AddSegment("file2.ts", 10 * kTimeScale, 30 * kTimeScale,
+                              kZeroByteOffset, 5 * kMBytes);
+
+  const char kExpectedOutput[] =
+      "#EXTM3U\n"
+      "#EXT-X-VERSION:6\n"
+      "## Generated with https://github.com/google/shaka-packager version "
+      "test\n"
+      "#EXT-X-TARGETDURATION:25\n"
+      "#EXT-X-PLAYLIST-TYPE:VOD\n"
+      "#EXT-X-I-FRAMES-ONLY\n"
+      "#EXTINF:2.000,\n"
+      "#EXT-X-BYTERANGE:2345@1000\n"
+      "file1.ts\n"
+      "#EXTINF:9.000,\n"
+      "#EXT-X-BYTERANGE:6345@5000\n"
+      "file1.ts\n"
+      "#EXT-X-PLACEMENT-OPPORTUNITY\n"
+      "#EXTINF:4.000,\n"
+      "#EXT-X-BYTERANGE:2345@1000\n"
+      "file2.ts\n"
+      "#EXTINF:25.000,\n"
+      "#EXT-X-BYTERANGE:12345\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);
+}
+
 namespace {
 const int kNumPreservedSegmentsOutsideLiveWindow = 3;
 const int kMaxNumSegmentsAvailable =