diff --git a/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/bear-english-text.vtt b/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/bear-english-text.vtt
index 30e81dfea0..18ae752fe8 100644
--- a/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/bear-english-text.vtt
+++ b/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/bear-english-text.vtt
@@ -3,9 +3,9 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/output.mpd b/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/output.mpd
index c6de0c9286..958ec27b1d 100644
--- a/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/output.mpd
+++ b/packager/app/test/testdata/audio-video-with-accessibilities-and-roles/output.mpd
@@ -23,7 +23,7 @@
     </AdaptationSet>
     <AdaptationSet id="2" contentType="text" subsegmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="caption"/>
-      <Representation id="2" bandwidth="273" mimeType="text/vtt">
+      <Representation id="2" bandwidth="317" mimeType="text/vtt">
         <BaseURL>bear-english-text.vtt</BaseURL>
       </Representation>
     </AdaptationSet>
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-1.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-1.vtt
index cd7ad3d7bd..d436f57266 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-1.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-1.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-2.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-2.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-2.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-2.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-3.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-3.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-3.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-3.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-4.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-4.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-4.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-4.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-5.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-5.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-5.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-5.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-6.vtt b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-6.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-6.vtt
+++ b/packager/app/test/testdata/hls-audio-video-text-with-ad-cues/bear-english-text-6.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.m4s b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.m4s
index 7f6fea5f03..9ce5e4e24f 100644
Binary files a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.m4s and b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.m4s differ
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.vtt b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.vtt
index cd7ad3d7bd..d436f57266 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.vtt
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-1.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.m4s b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.m4s
index a59e2a79ad..119b4f5ada 100644
Binary files a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.m4s and b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.m4s differ
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.vtt b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.vtt
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-2.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.m4s b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.m4s
index 08140209f9..6e04798996 100644
Binary files a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.m4s and b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.m4s differ
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.vtt b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.vtt
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-3.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.m4s b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.m4s
index 666cbc3c1e..48c319aea7 100644
Binary files a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.m4s and b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.m4s differ
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.vtt b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.vtt
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-4.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.m4s b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.m4s
index 5c8f82c5da..7f77e260ea 100644
Binary files a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.m4s and b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.m4s differ
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.vtt b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.vtt
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/bear-english-text-5.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-only-dash-only-captions/output.mpd b/packager/app/test/testdata/hls-only-dash-only-captions/output.mpd
index 1644042a48..2efb24609d 100644
--- a/packager/app/test/testdata/hls-only-dash-only-captions/output.mpd
+++ b/packager/app/test/testdata/hls-only-dash-only-captions/output.mpd
@@ -26,7 +26,7 @@
     </AdaptationSet>
     <AdaptationSet id="2" contentType="text" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="2" bandwidth="2056" codecs="wvtt" mimeType="application/mp4">
+      <Representation id="2" bandwidth="2216" codecs="wvtt" mimeType="application/mp4">
         <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="1000" r="4"/>
diff --git a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-1.vtt b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-1.vtt
index 0e343feb32..cb9ac12df0 100644
--- a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-1.vtt
+++ b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-1.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
diff --git a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-2.vtt b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-2.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-2.vtt
+++ b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-2.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-3.vtt b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-3.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-3.vtt
+++ b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-3.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-4.vtt b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-4.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-4.vtt
+++ b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-4.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-5.vtt b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-5.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-5.vtt
+++ b/packager/app/test/testdata/hls-segmented-webvtt/bear-english-text-5.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-1.m4s b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-1.m4s
index 7f6fea5f03..9ce5e4e24f 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-1.m4s and b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-1.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-2.m4s b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-2.m4s
index a59e2a79ad..119b4f5ada 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-2.m4s and b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-2.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-3.m4s b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-3.m4s
index 08140209f9..6e04798996 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-3.m4s and b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-3.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-4.m4s b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-4.m4s
index 666cbc3c1e..48c319aea7 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-4.m4s and b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-4.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-5.m4s b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-5.m4s
index 5c8f82c5da..7f77e260ea 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-5.m4s and b/packager/app/test/testdata/segmented-webvtt-mp4/bear-english-text-5.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-mp4/output.mpd b/packager/app/test/testdata/segmented-webvtt-mp4/output.mpd
index 2979d0fbe8..947a122468 100644
--- a/packager/app/test/testdata/segmented-webvtt-mp4/output.mpd
+++ b/packager/app/test/testdata/segmented-webvtt-mp4/output.mpd
@@ -4,7 +4,7 @@
   <Period id="0" start="PT0S">
     <AdaptationSet id="0" contentType="text" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="0" bandwidth="2056" codecs="wvtt" mimeType="application/mp4">
+      <Representation id="0" bandwidth="2216" codecs="wvtt" mimeType="application/mp4">
         <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="1000" r="4"/>
diff --git a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-1.vtt b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-1.vtt
index 0e343feb32..cb9ac12df0 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-1.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-1.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-2.vtt b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-2.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-2.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-2.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-3.vtt b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-3.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-3.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-3.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-4.vtt b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-4.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-4.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-4.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-5.vtt b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-5.vtt
index 8597f536ab..c4d88d32b7 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-5.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-text/bear-english-text-5.vtt
@@ -4,6 +4,6 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-text/output.mpd b/packager/app/test/testdata/segmented-webvtt-text/output.mpd
index 78c74aa517..dd4aa441d3 100644
--- a/packager/app/test/testdata/segmented-webvtt-text/output.mpd
+++ b/packager/app/test/testdata/segmented-webvtt-text/output.mpd
@@ -4,7 +4,7 @@
   <Period id="0" start="PT0S">
     <AdaptationSet id="0" contentType="text" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="0" bandwidth="1216" mimeType="text/vtt">
+      <Representation id="0" bandwidth="1320" mimeType="text/vtt">
         <SegmentTemplate timescale="1000" media="bear-english-text-$Number$.vtt" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="1000" r="4"/>
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.m4s b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.m4s
index 7f6fea5f03..9ce5e4e24f 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.m4s and b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.vtt b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.vtt
index cd7ad3d7bd..d436f57266 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-1.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.m4s b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.m4s
index a59e2a79ad..119b4f5ada 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.m4s and b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.vtt b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-2.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.m4s b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.m4s
index 08140209f9..6e04798996 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.m4s and b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.vtt b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-3.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.m4s b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.m4s
index 666cbc3c1e..48c319aea7 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.m4s and b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.vtt b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-4.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.m4s b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.m4s
index 5c8f82c5da..7f77e260ea 100644
Binary files a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.m4s and b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.m4s differ
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.vtt b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.vtt
index ae16c7bd9a..a2dc27b707 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.vtt
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/bear-english-text-5.vtt
@@ -3,6 +3,6 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/segmented-webvtt-with-language-override/output.mpd b/packager/app/test/testdata/segmented-webvtt-with-language-override/output.mpd
index ac0d53be9f..18e6002594 100644
--- a/packager/app/test/testdata/segmented-webvtt-with-language-override/output.mpd
+++ b/packager/app/test/testdata/segmented-webvtt-with-language-override/output.mpd
@@ -4,7 +4,7 @@
   <Period id="0" start="PT0S">
     <AdaptationSet id="0" contentType="text" lang="pt" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="0" bandwidth="2056" codecs="wvtt" mimeType="application/mp4">
+      <Representation id="0" bandwidth="2216" codecs="wvtt" mimeType="application/mp4">
         <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="1000" r="4"/>
diff --git a/packager/app/test/testdata/single-file-webvtt-text/bear-english-text.vtt b/packager/app/test/testdata/single-file-webvtt-text/bear-english-text.vtt
index 6f20be5417..b1a4829aa2 100644
--- a/packager/app/test/testdata/single-file-webvtt-text/bear-english-text.vtt
+++ b/packager/app/test/testdata/single-file-webvtt-text/bear-english-text.vtt
@@ -4,9 +4,9 @@ X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:9000
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/single-file-webvtt-text/output.mpd b/packager/app/test/testdata/single-file-webvtt-text/output.mpd
index e0317579b1..46291f3ef6 100644
--- a/packager/app/test/testdata/single-file-webvtt-text/output.mpd
+++ b/packager/app/test/testdata/single-file-webvtt-text/output.mpd
@@ -4,7 +4,7 @@
   <Period id="0">
     <AdaptationSet id="0" contentType="text" subsegmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="0" bandwidth="353" mimeType="text/vtt">
+      <Representation id="0" bandwidth="397" mimeType="text/vtt">
         <BaseURL>bear-english-text.vtt</BaseURL>
       </Representation>
     </AdaptationSet>
diff --git a/packager/app/test/testdata/video-audio-webvtt/bear-english-text.vtt b/packager/app/test/testdata/video-audio-webvtt/bear-english-text.vtt
index 30e81dfea0..18ae752fe8 100644
--- a/packager/app/test/testdata/video-audio-webvtt/bear-english-text.vtt
+++ b/packager/app/test/testdata/video-audio-webvtt/bear-english-text.vtt
@@ -3,9 +3,9 @@ WEBVTT
 STYLE
 ::cue { color:lime }
 
-00:00:00.000 --> 00:00:00.800
+00:00:00.000 --> 00:00:00.800 align:center
 Yup, that's a bear, eh.
 
-00:00:01.000 --> 00:00:04.700
+00:00:01.000 --> 00:00:04.700 align:center
 He 's... um... doing bear-like stuff.
 
diff --git a/packager/app/test/testdata/video-audio-webvtt/output.mpd b/packager/app/test/testdata/video-audio-webvtt/output.mpd
index 2e57b85d86..d7ce2e3212 100644
--- a/packager/app/test/testdata/video-audio-webvtt/output.mpd
+++ b/packager/app/test/testdata/video-audio-webvtt/output.mpd
@@ -21,7 +21,7 @@
     </AdaptationSet>
     <AdaptationSet id="2" contentType="text" subsegmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="2" bandwidth="273" mimeType="text/vtt">
+      <Representation id="2" bandwidth="317" mimeType="text/vtt">
         <BaseURL>bear-english-text.vtt</BaseURL>
       </Representation>
     </AdaptationSet>
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-1.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-1.m4s
index 7f6fea5f03..9ce5e4e24f 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-1.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-1.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-2.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-2.m4s
index a59e2a79ad..119b4f5ada 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-2.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-2.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-3.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-3.m4s
index 0f434e3d9b..d4c71e3b8b 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-3.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-3.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-4.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-4.m4s
index a03dd2653e..6383454b9b 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-4.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-4.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-5.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-5.m4s
index 14d335f2d9..737e12bf8d 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-5.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-5.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-6.m4s b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-6.m4s
index c39fd9adff..026636592d 100644
Binary files a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-6.m4s and b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/bear-english-text-6.m4s differ
diff --git a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/output.mpd b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/output.mpd
index 0f9f7cc45f..180a492dbd 100644
--- a/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/output.mpd
+++ b/packager/app/test/testdata/vtt-text-to-mp4-with-ad-cues/output.mpd
@@ -24,7 +24,7 @@
     </AdaptationSet>
     <AdaptationSet id="2" contentType="text" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="2" bandwidth="1944" codecs="wvtt" mimeType="application/mp4">
+      <Representation id="2" bandwidth="2104" codecs="wvtt" mimeType="application/mp4">
         <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="1000" r="1"/>
@@ -56,7 +56,7 @@
     </AdaptationSet>
     <AdaptationSet id="2" contentType="text" segmentAlignment="true">
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="2" bandwidth="2056" codecs="wvtt" mimeType="application/mp4">
+      <Representation id="2" bandwidth="2216" codecs="wvtt" mimeType="application/mp4">
         <SegmentTemplate timescale="1000" presentationTimeOffset="2001" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="4">
           <SegmentTimeline>
             <S t="2001" d="1000" r="2"/>
diff --git a/packager/media/formats/webvtt/webvtt_muxer_unittest.cc b/packager/media/formats/webvtt/webvtt_muxer_unittest.cc
index 16cbb356a8..77dd516c38 100644
--- a/packager/media/formats/webvtt/webvtt_muxer_unittest.cc
+++ b/packager/media/formats/webvtt/webvtt_muxer_unittest.cc
@@ -83,7 +83,7 @@ TEST_F(WebVttMuxerTest, WithOneSegmentAndWithOneSample) {
   const char* kExpectedOutput =
       "WEBVTT\n"
       "\n"
-      "00:00:05.000 --> 00:00:06.000\n"
+      "00:00:05.000 --> 00:00:06.000 align:center\n"
       "payload\n"
       "\n";
 
@@ -122,14 +122,14 @@ TEST_F(WebVttMuxerTest, WithTwoSegmentAndWithOneSample) {
   const char* kExpectedOutput1 =
       "WEBVTT\n"
       "\n"
-      "00:00:05.000 --> 00:00:06.000\n"
+      "00:00:05.000 --> 00:00:06.000 align:center\n"
       "payload 1\n"
       "\n";
 
   const char* kExpectedOutput2 =
       "WEBVTT\n"
       "\n"
-      "00:00:15.000 --> 00:00:16.000\n"
+      "00:00:15.000 --> 00:00:16.000 align:center\n"
       "payload 2\n"
       "\n";
 
@@ -189,7 +189,7 @@ TEST_F(WebVttMuxerTest, WithAnEmptySegment) {
   const char* kExpectedOutput2 =
       "WEBVTT\n"
       "\n"
-      "00:00:15.000 --> 00:00:16.000\n"
+      "00:00:15.000 --> 00:00:16.000 align:center\n"
       "payload 2\n"
       "\n";
 
diff --git a/packager/media/formats/webvtt/webvtt_utils.cc b/packager/media/formats/webvtt/webvtt_utils.cc
index 2d23ca5498..bb0bea3481 100644
--- a/packager/media/formats/webvtt/webvtt_utils.cc
+++ b/packager/media/formats/webvtt/webvtt_utils.cc
@@ -249,6 +249,7 @@ std::string WebVttSettingsToString(const TextSettings& settings) {
       ret += " align:right";
       break;
     case TextAlignment::kCenter:
+      ret += " align:center";
       break;
   }
 
diff --git a/packager/media/formats/webvtt/webvtt_utils_unittest.cc b/packager/media/formats/webvtt/webvtt_utils_unittest.cc
index bb405b9cb9..eb4281ef96 100644
--- a/packager/media/formats/webvtt/webvtt_utils_unittest.cc
+++ b/packager/media/formats/webvtt/webvtt_utils_unittest.cc
@@ -163,9 +163,10 @@ TEST(WebVttUtilsTest, SettingsToString) {
 TEST(WebVttUtilsTest, SettingsToString_IgnoresDefaults) {
   TextSettings settings;
   settings.region = "foo";
+  settings.text_alignment = TextAlignment::kCenter;
 
   const auto actual = WebVttSettingsToString(settings);
-  EXPECT_EQ(actual, "region:foo");
+  EXPECT_EQ(actual, "region:foo align:center");
 }
 
 TEST(WebVttUtilsTest, FragmentToString) {