diff --git a/packager/media/formats/webm/multi_segment_segmenter_unittest.cc b/packager/media/formats/webm/multi_segment_segmenter_unittest.cc
index b8155b848a..b6328ef6ae 100644
--- a/packager/media/formats/webm/multi_segment_segmenter_unittest.cc
+++ b/packager/media/formats/webm/multi_segment_segmenter_unittest.cc
@@ -16,7 +16,7 @@ namespace {
 const uint64_t kDuration = 1000;
 
 const uint8_t kBasicSupportDataInit[] = {
-  // ID: EBML Header, Size: 31
+  // ID: EBML Header, Payload Size: 31
   0x1a, 0x45, 0xdf, 0xa3, 0x9f,
     // EBMLVersion: 1
     0x42, 0x86, 0x81, 0x01,
@@ -32,9 +32,9 @@ const uint8_t kBasicSupportDataInit[] = {
     0x42, 0x87, 0x81, 0x02,
     // DocTypeReadVersion: 2
     0x42, 0x85, 0x81, 0x02,
-  // ID: Segment, Size: -1
+  // ID: Segment, Payload Size: Unknown
   0x18, 0x53, 0x80, 0x67, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-    // ID: Void, Size: 87
+    // ID: Void, Payload Size: 87
     0xec, 0xd7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -43,21 +43,25 @@ const uint8_t kBasicSupportDataInit[] = {
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00,
-    // ID: Info, size: 50
-    0x15, 0x49, 0xa9, 0x66, 0xb2,
+    // ID: Info, Payload Size: 88
+    0x15, 0x49, 0xa9, 0x66, 0xd8,
       // TimecodeScale: 1000000
       0x2a, 0xd7, 0xb1, 0x83, 0x0f, 0x42, 0x40,
-      // Duration: float(5000)
+      // Duration: float(0)
       0x44, 0x89, 0x84, 0x3f, 0x80, 0x00, 0x00,
       // MuxingApp: 'libwebm-0.2.1.0'
       0x4d, 0x80, 0x8f, 0x6c, 0x69, 0x62, 0x77, 0x65, 0x62, 0x6d, 0x2d, 0x30,
       0x2e, 0x32, 0x2e, 0x31, 0x2e, 0x30,
-      // WritingApp: 'libwebm-0.2.1.0'
-      0x57, 0x41, 0x8f, 0x6c, 0x69, 0x62, 0x77, 0x65, 0x62, 0x6d, 0x2d, 0x30,
-      0x2e, 0x32, 0x2e, 0x31, 0x2e, 0x30,
-    // ID: Tracks, size: 41
+      // WritingApp: 'https://github.com/google/edash-packager version test'
+      0x57, 0x41, 0xb5,
+      0x68, 0x74, 0x74, 0x70, 0x73, 0x3a, 0x2f, 0x2f, 0x67, 0x69, 0x74, 0x68,
+      0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6f, 0x67, 0x6c,
+      0x65, 0x2f, 0x65, 0x64, 0x61, 0x73, 0x68, 0x2d, 0x70, 0x61, 0x63, 0x6b,
+      0x61, 0x67, 0x65, 0x72, 0x20, 0x76, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e,
+      0x20, 0x74, 0x65, 0x73, 0x74,
+    // ID: Tracks, Payload Size: 41
     0x16, 0x54, 0xae, 0x6b, 0xa9,
-      // ID: Track, size: 39
+      // ID: Track, Payload Size: 39
       0xae, 0xa7,
         // TrackNumber: 1
         0xd7, 0x81, 0x01,
@@ -69,7 +73,7 @@ const uint8_t kBasicSupportDataInit[] = {
         0x86, 0x85, 0x56, 0x5f, 0x56, 0x50, 0x38,
         // Language: 'en'
         0x22, 0xb5, 0x9c, 0x82, 0x65, 0x6e,
-        // ID: Video, Size: 14
+        // ID: Video, Payload Size: 14
         0xe0, 0x8e,
           // PixelWidth: 100
           0xb0, 0x81, 0x64,
@@ -81,19 +85,19 @@ const uint8_t kBasicSupportDataInit[] = {
           0x54, 0xba, 0x81, 0x64
 };
 const uint8_t kBasicSupportDataSegment[] = {
-  // ID: Cluster, size: 58
+  // ID: Cluster, Payload Size: 58
   0x1f, 0x43, 0xb6, 0x75, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3a,
     // Timecode: 0
     0xe7, 0x81, 0x00,
-    // ID: SimpleBlock, Size: 9
+    // ID: SimpleBlock, Payload Size: 9
     0xa3, 0x89, 0x81, 0x00, 0x00, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-    // ID: SimpleBlock, Size: 9
+    // ID: SimpleBlock, Payload Size: 9
     0xa3, 0x89, 0x81, 0x03, 0xe8, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-    // ID: SimpleBlock, Size: 9
+    // ID: SimpleBlock, Payload Size: 9
     0xa3, 0x89, 0x81, 0x07, 0xd0, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-    // ID: SimpleBlock, Size: 9
+    // ID: SimpleBlock, Payload Size: 9
     0xa3, 0x89, 0x81, 0x0b, 0xb8, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-    // ID: SimpleBlock, Size: 9
+    // ID: SimpleBlock, Payload Size: 9
     0xa3, 0x89, 0x81, 0x0f, 0xa0, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00
 };
 
diff --git a/packager/media/formats/webm/segmenter.cc b/packager/media/formats/webm/segmenter.cc
index 6517c5fd25..a0f5dbde77 100644
--- a/packager/media/formats/webm/segmenter.cc
+++ b/packager/media/formats/webm/segmenter.cc
@@ -54,8 +54,13 @@ Status Segmenter::Initialize(scoped_ptr<MkvWriter> writer,
   progress_target_ = info_->duration();
   progress_listener_ = progress_listener;
 
+  const std::string version_string =
+      "https://github.com/google/edash-packager version " +
+      options().packager_version_string;
+
   segment_info_.Init();
   segment_info_.set_timecode_scale(kTimecodeScale);
+  segment_info_.set_writing_app(version_string.c_str());
   if (options().single_segment) {
     // Set an initial duration so the duration element is written; will be
     // overwritten at the end.
diff --git a/packager/media/formats/webm/segmenter_test_base.cc b/packager/media/formats/webm/segmenter_test_base.cc
index e1b0d86019..6fb33f76d4 100644
--- a/packager/media/formats/webm/segmenter_test_base.cc
+++ b/packager/media/formats/webm/segmenter_test_base.cc
@@ -63,6 +63,7 @@ MuxerOptions SegmentTestBase::CreateMuxerOptions() const {
   ret.single_segment = single_segment_;
   ret.output_file_name = output_file_name_;
   ret.segment_template = segment_template_;
+  ret.packager_version_string = "test";
   ret.segment_duration = 30;  // seconds
   ret.fragment_duration = 30;  // seconds
   ret.segment_sap_aligned = false;
diff --git a/packager/media/formats/webm/segmenter_test_base.h b/packager/media/formats/webm/segmenter_test_base.h
index fa6bd2168d..af1bb775b1 100644
--- a/packager/media/formats/webm/segmenter_test_base.h
+++ b/packager/media/formats/webm/segmenter_test_base.h
@@ -40,7 +40,7 @@ class SegmentTestBase : public ::testing::Test {
     scoped_ptr<S> segmenter(new S(options));
 
     scoped_ptr<MkvWriter> writer(new MkvWriter());
-    ASSERT_OK(writer->Open(this->output_file_name_));
+    ASSERT_OK(writer->Open(options.output_file_name));
     ASSERT_OK(segmenter->Initialize(writer.Pass(), info, NULL, NULL, NULL));
     *result = segmenter.Pass();
   }
diff --git a/packager/media/formats/webm/single_segment_segmenter_unittest.cc b/packager/media/formats/webm/single_segment_segmenter_unittest.cc
index 741b1f9ce2..0033082c67 100644
--- a/packager/media/formats/webm/single_segment_segmenter_unittest.cc
+++ b/packager/media/formats/webm/single_segment_segmenter_unittest.cc
@@ -17,7 +17,7 @@ namespace {
 const uint64_t kDuration = 1000;
 
 const uint8_t kBasicSupportData[] = {
-  // ID: EBML Header, Size: 31
+  // ID: EBML Header, Payload Size: 31
   0x1a, 0x45, 0xdf, 0xa3, 0x9f,
     // EBMLVersion: 1
     0x42, 0x86, 0x81, 0x01,
@@ -33,30 +33,30 @@ const uint8_t kBasicSupportData[] = {
     0x42, 0x87, 0x81, 0x02,
     // DocTypeReadVersion: 2
     0x42, 0x85, 0x81, 0x02,
-  // ID: Segment, Size: 287
-  0x18, 0x53, 0x80, 0x67, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x16,
-    // ID: SeekHead, Size: 29
-    0x11, 0x4d, 0x9b, 0x74, 0x9d,
-      // ID: Seek, Size: 11
-      0x4d, 0xbb, 0x8b,
-        // SeekID: binary(4)
-        0x53, 0xab, 0x84, 0x1f, 0x43, 0xb6, 0x75,
-        // SeekPosition: 238
-        0x53, 0xac, 0x81, 0xee,
-      // ID: Seek, Size: 12
+  // ID: Segment, Payload Size: 316
+  0x18, 0x53, 0x80, 0x67, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x3c,
+    // ID: SeekHead, Payload Size: 30
+    0x11, 0x4d, 0x9b, 0x74, 0x9e,
+      // ID: Seek, Payload Size: 12
       0x4d, 0xbb, 0x8c,
-        // SeekID: binary(4)
+        // SeekID: binary(4) (Cluster)
+        0x53, 0xab, 0x84, 0x1f, 0x43, 0xb6, 0x75,
+        // SeekPosition: 276
+        0x53, 0xac, 0x82, 0x01, 0x14,
+      // ID: Seek, Payload Size: 12
+      0x4d, 0xbb, 0x8c,
+        // SeekID: binary(4) (Cues)
         0x53, 0xab, 0x84, 0x1c, 0x53, 0xbb, 0x6b,
-        // SeekPosition: 174
-        0x53, 0xac, 0x82, 0x01, 0x34,
-    // ID: Void, Size: 53
-    0xec, 0xb5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        // SeekPosition: 346
+        0x53, 0xac, 0x82, 0x01, 0x5a,
+    // ID: Void, Payload Size: 52
+    0xec, 0xb4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-    // ID: Info, size: 50
-    0x15, 0x49, 0xa9, 0x66, 0xb2,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    // ID: Info, Payload Size: 88
+    0x15, 0x49, 0xa9, 0x66, 0xd8,
       // TimecodeScale: 1000000
       0x2a, 0xd7, 0xb1, 0x83, 0x0f, 0x42, 0x40,
       // Duration: float(5000)
@@ -64,12 +64,16 @@ const uint8_t kBasicSupportData[] = {
       // MuxingApp: 'libwebm-0.2.1.0'
       0x4d, 0x80, 0x8f, 0x6c, 0x69, 0x62, 0x77, 0x65, 0x62, 0x6d, 0x2d, 0x30,
       0x2e, 0x32, 0x2e, 0x31, 0x2e, 0x30,
-      // WritingApp: 'libwebm-0.2.1.0'
-      0x57, 0x41, 0x8f, 0x6c, 0x69, 0x62, 0x77, 0x65, 0x62, 0x6d, 0x2d, 0x30,
-      0x2e, 0x32, 0x2e, 0x31, 0x2e, 0x30,
-    // ID: Tracks, size: 41
+      // WritingApp: 'https://github.com/google/edash-packager version test'
+      0x57, 0x41, 0xb5,
+      0x68, 0x74, 0x74, 0x70, 0x73, 0x3a, 0x2f, 0x2f, 0x67, 0x69, 0x74, 0x68,
+      0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6f, 0x67, 0x6c,
+      0x65, 0x2f, 0x65, 0x64, 0x61, 0x73, 0x68, 0x2d, 0x70, 0x61, 0x63, 0x6b,
+      0x61, 0x67, 0x65, 0x72, 0x20, 0x76, 0x65, 0x72, 0x73, 0x69, 0x6f, 0x6e,
+      0x20, 0x74, 0x65, 0x73, 0x74,
+    // ID: Tracks, Payload Size: 41
     0x16, 0x54, 0xae, 0x6b, 0xa9,
-      // ID: Track, size: 39
+      // ID: Track, Payload Size: 39
       0xae, 0xa7,
         // TrackNumber: 1
         0xd7, 0x81, 0x01,
@@ -81,7 +85,7 @@ const uint8_t kBasicSupportData[] = {
         0x86, 0x85, 0x56, 0x5f, 0x56, 0x50, 0x38,
         // Language: 'en'
         0x22, 0xb5, 0x9c, 0x82, 0x65, 0x6e,
-        // ID: Video, Size: 14
+        // ID: Video, Payload Size: 14
         0xe0, 0x8e,
           // PixelWidth: 100
           0xb0, 0x81, 0x64,
@@ -91,32 +95,32 @@ const uint8_t kBasicSupportData[] = {
           0x54, 0xb0, 0x81, 0x64,
           // DisplayHeight: 100
           0x54, 0xba, 0x81, 0x64,
-    // ID: Cluster, size: 58
+    // ID: Cluster, Payload Size: 58
     0x1f, 0x43, 0xb6, 0x75, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3a,
       // Timecode: 0
       0xe7, 0x81, 0x00,
-      // ID: SimpleBlock, Size: 9
+      // ID: SimpleBlock, Payload Size: 9
       0xa3, 0x89, 0x81, 0x00, 0x00, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-      // ID: SimpleBlock, Size: 9
+      // ID: SimpleBlock, Payload Size: 9
       0xa3, 0x89, 0x81, 0x03, 0xe8, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-      // ID: SimpleBlock, Size: 9
+      // ID: SimpleBlock, Payload Size: 9
       0xa3, 0x89, 0x81, 0x07, 0xd0, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-      // ID: SimpleBlock, Size: 9
+      // ID: SimpleBlock, Payload Size: 9
       0xa3, 0x89, 0x81, 0x0b, 0xb8, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-      // ID: SimpleBlock, Size: 9
+      // ID: SimpleBlock, Payload Size: 9
       0xa3, 0x89, 0x81, 0x0f, 0xa0, 0x80, 0xde, 0xad, 0xbe, 0xef, 0x00,
-    // ID: Cues, Size: 13
+    // ID: Cues, Payload Size: 13
     0x1c, 0x53, 0xbb, 0x6b, 0x8d,
-      // ID: CuePoint, Size: 11
+      // ID: CuePoint, Payload Size: 11
       0xbb, 0x8b,
         // CueTime: 0
         0xb3, 0x81, 0x00,
-        // ID: CueTrackPositions, Size: 6
+        // ID: CueTrackPositions, Payload Size: 6
         0xb7, 0x86,
           // CueTrack: 1
           0xf7, 0x81, 0x01,
-          // CueClusterPosition: 190
-          0xf1, 0x81, 0xbe
+          // CueClusterPosition: 228
+          0xf1, 0x81, 0xe4
 };
 
 }  // namespace