From 1522079eb8e93323fdf7fd8d8f96e0b71914311e Mon Sep 17 00:00:00 2001
From: Anthony Lu <koln@google.com>
Date: Wed, 2 Sep 2020 23:16:25 +0000
Subject: [PATCH 1/3] use second sample in webm and mp4 formats

---
 packager/media/formats/mp4/segmenter.cc  |  6 ++++--
 packager/media/formats/mp4/segmenter.h   |  5 +++--
 packager/media/formats/webm/segmenter.cc | 12 +++++++-----
 packager/media/formats/webm/segmenter.h  |  3 ++-
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/packager/media/formats/mp4/segmenter.cc b/packager/media/formats/mp4/segmenter.cc
index cce500dea49..5a8a9147193 100644
--- a/packager/media/formats/mp4/segmenter.cc
+++ b/packager/media/formats/mp4/segmenter.cc
@@ -138,8 +138,10 @@ Status Segmenter::AddSample(size_t stream_id, const MediaSample& sample) {
   if (!status.ok())
     return status;
 
-  if (sample_duration_ == 0)
-    sample_duration_ = sample.duration();
+  if (num_samples_ < 2) {
+    sample_durations_[num_samples_] = sample.duration();
+    num_samples_++;
+  }
   stream_durations_[stream_id] += sample.duration();
   return Status::OK;
 }
diff --git a/packager/media/formats/mp4/segmenter.h b/packager/media/formats/mp4/segmenter.h
index 724c12ef6fc..febdfb1fa1e 100644
--- a/packager/media/formats/mp4/segmenter.h
+++ b/packager/media/formats/mp4/segmenter.h
@@ -98,7 +98,7 @@ class Segmenter {
 
   /// @return The sample duration in the timescale of the media.
   ///         Returns 0 if no samples are added yet.
-  uint32_t sample_duration() const { return sample_duration_; }
+  uint32_t sample_duration() const { return sample_durations_[1]; }
 
  protected:
   /// Update segmentation progress using ProgressListener.
@@ -144,7 +144,8 @@ class Segmenter {
   ProgressListener* progress_listener_ = nullptr;
   uint64_t progress_target_ = 0u;
   uint64_t accumulated_progress_ = 0u;
-  uint32_t sample_duration_ = 0u;
+  uint32_t sample_durations_[2] = {0, 0};
+  uint32_t num_samples_ = 0u;
   std::vector<uint64_t> stream_durations_;
   std::vector<KeyFrameInfo> key_frame_infos_;
 
diff --git a/packager/media/formats/webm/segmenter.cc b/packager/media/formats/webm/segmenter.cc
index b3ffdcfb188..e2479e0bc44 100644
--- a/packager/media/formats/webm/segmenter.cc
+++ b/packager/media/formats/webm/segmenter.cc
@@ -161,11 +161,13 @@ Status Segmenter::Finalize() {
 Status Segmenter::AddSample(const MediaSample& source_sample) {
   std::shared_ptr<MediaSample> sample(source_sample.Clone());
 
-  if (sample_duration_ == 0) {
-    first_timestamp_ = sample->pts();
-    sample_duration_ = sample->duration();
-    if (muxer_listener_)
-      muxer_listener_->OnSampleDurationReady(sample_duration_);
+  if (num_samples_ < 2) {
+    if (num_samples_ == 0)
+      first_timestamp_ = sample->pts();
+    else 
+      muxer_listener_->OnSampleDurationReady(sample_durations_[num_samples_]);
+    sample_durations_[num_samples_] = sample->duration();
+    num_samples_++;
   }
 
   UpdateProgress(sample->duration());
diff --git a/packager/media/formats/webm/segmenter.h b/packager/media/formats/webm/segmenter.h
index f6c7c2184d1..2ab0bcc21fa 100644
--- a/packager/media/formats/webm/segmenter.h
+++ b/packager/media/formats/webm/segmenter.h
@@ -139,7 +139,8 @@ class Segmenter {
   uint64_t progress_target_ = 0;
   uint64_t accumulated_progress_ = 0;
   uint64_t first_timestamp_ = 0;
-  int64_t sample_duration_ = 0;
+  int64_t sample_durations_[2] = {0, 0};
+  int64_t num_samples_ = 0;
   // The position (in bytes) of the start of the Segment payload in the init
   // file.  This is also the size of the header before the SeekHead.
   uint64_t segment_payload_pos_ = 0;

From 393c2c841689d16e670be1760f41a06c4cebc975 Mon Sep 17 00:00:00 2001
From: Anthony Lu <koln@google.com>
Date: Thu, 3 Sep 2020 18:44:17 +0000
Subject: [PATCH 2/3] missed line

---
 packager/media/formats/webm/segmenter.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packager/media/formats/webm/segmenter.cc b/packager/media/formats/webm/segmenter.cc
index e2479e0bc44..85c3101abe9 100644
--- a/packager/media/formats/webm/segmenter.cc
+++ b/packager/media/formats/webm/segmenter.cc
@@ -162,11 +162,11 @@ Status Segmenter::AddSample(const MediaSample& source_sample) {
   std::shared_ptr<MediaSample> sample(source_sample.Clone());
 
   if (num_samples_ < 2) {
+    sample_durations_[num_samples_] = sample->duration();
     if (num_samples_ == 0)
       first_timestamp_ = sample->pts();
     else 
       muxer_listener_->OnSampleDurationReady(sample_durations_[num_samples_]);
-    sample_durations_[num_samples_] = sample->duration();
     num_samples_++;
   }
 

From 30a6aa85fd96bce195d29fdac5e8e878cb9de9bd Mon Sep 17 00:00:00 2001
From: Anthony Lu <koln@google.com>
Date: Tue, 8 Sep 2020 23:48:32 +0000
Subject: [PATCH 3/3] end to end update

---
 .../output.mpd                                | 34 +++++++-------
 .../output.mpd                                |  4 +-
 .../output.m3u8                               |  2 +-
 .../encryption-and-two-trick-plays/output.mpd |  4 +-
 .../hls-only-dash-only-captions/output.mpd    | 20 ++++-----
 .../output.mpd                                | 24 +++++-----
 .../live-profile-with-webm/output.m3u8        |  2 +-
 .../live-profile-with-webm/output.mpd         |  2 +-
 .../opus-vp9-mp4-with-encryption/output.mpd   |  2 +-
 .../vp8-mp4-with-encryption/output.mpd        |  2 +-
 .../app/test/testdata/vp8-webm/output.mpd     |  2 +-
 .../vp9-webm-with-blockgroup/output.mpd       |  2 +-
 .../app/test/testdata/vp9-webm/output.mpd     |  2 +-
 .../vtt-text-to-mp4-with-ad-cues/output.mpd   | 44 +++++++++----------
 .../webm-subsample-encryption/output.mpd      |  2 +-
 .../output.mpd                                |  2 +-
 .../testdata/webm-with-encryption/output.mpd  |  2 +-
 packager/media/formats/mp4/segmenter.h        |  4 +-
 packager/media/formats/webm/segmenter.cc      |  2 +-
 packager/media/formats/webm/segmenter.h       |  2 +-
 20 files changed, 80 insertions(+), 80 deletions(-)

diff --git a/packager/app/test/testdata/audio-video-with-codec-switching-encryption-trick-play/output.mpd b/packager/app/test/testdata/audio-video-with-codec-switching-encryption-trick-play/output.mpd
index 54d9782cb8b..2ebb04eb3a4 100644
--- a/packager/app/test/testdata/audio-video-with-codec-switching-encryption-trick-play/output.mpd
+++ b/packager/app/test/testdata/audio-video-with-codec-switching-encryption-trick-play/output.mpd
@@ -2,28 +2,14 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" xmlns:cenc="urn:mpeg:cenc:2013" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.802799940109253S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="30000/1001" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" maxWidth="1280" maxHeight="720" frameRate="30000/1001" subsegmentAlignment="true" par="16:9">
       <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
       <SupplementalProperty schemeIdUri="urn:mpeg:dash:adaptation-set-switching:2016" value="1"/>
       <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
-      <Representation id="0" bandwidth="281671" codecs="hev1.1.6.L63.90" mimeType="video/mp4" sar="1:1">
-        <BaseURL>bear-640x360-hevc-video.mp4</BaseURL>
-        <SegmentBase indexRange="3211-3278" timescale="30000">
-          <Initialization range="0-3210"/>
-        </SegmentBase>
-      </Representation>
-    </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" maxWidth="1280" maxHeight="720" frameRate="30000/1001" subsegmentAlignment="true" par="16:9">
-      <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
-      <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
-        <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
-      </ContentProtection>
-      <SupplementalProperty schemeIdUri="urn:mpeg:dash:adaptation-set-switching:2016" value="0"/>
-      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
-      <Representation id="1" bandwidth="977743" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" width="640" height="360">
+      <Representation id="0" bandwidth="977743" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" width="640" height="360">
         <BaseURL>bear-640x360-video.mp4</BaseURL>
         <SegmentBase indexRange="1127-1194" timescale="30000">
           <Initialization range="0-1126"/>
@@ -36,6 +22,20 @@
         </SegmentBase>
       </Representation>
     </AdaptationSet>
+    <AdaptationSet id="1" contentType="video" width="640" height="360" frameRate="30000/1001" subsegmentAlignment="true" par="16:9">
+      <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
+      <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
+        <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
+      </ContentProtection>
+      <SupplementalProperty schemeIdUri="urn:mpeg:dash:adaptation-set-switching:2016" value="0"/>
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main"/>
+      <Representation id="1" bandwidth="281671" codecs="hev1.1.6.L63.90" mimeType="video/mp4" sar="1:1">
+        <BaseURL>bear-640x360-hevc-video.mp4</BaseURL>
+        <SegmentBase indexRange="3211-3278" timescale="30000">
+          <Initialization range="0-3210"/>
+        </SegmentBase>
+      </Representation>
+    </AdaptationSet>
     <AdaptationSet id="2" contentType="audio" subsegmentAlignment="true">
       <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
@@ -54,7 +54,7 @@
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
-      <EssentialProperty schemeIdUri="http://dashif.org/guidelines/trickmode" value="1"/>
+      <EssentialProperty schemeIdUri="http://dashif.org/guidelines/trickmode" value="0"/>
       <Representation id="4" bandwidth="470530" codecs="avc1.64001f" mimeType="video/mp4" sar="1:1" maxPlayoutRate="30" codingDependency="false">
         <BaseURL>bear-1280x720-video-trick_play_factor_1.mp4</BaseURL>
         <SegmentBase indexRange="1125-1192" timescale="30000">
diff --git a/packager/app/test/testdata/audio-video-with-two-trick-play/output.mpd b/packager/app/test/testdata/audio-video-with-two-trick-play/output.mpd
index 1585bc0a20d..5964d2ca93f 100644
--- a/packager/app/test/testdata/audio-video-with-two-trick-play/output.mpd
+++ b/packager/app/test/testdata/audio-video-with-two-trick-play/output.mpd
@@ -10,7 +10,7 @@
         </SegmentBase>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" width="640" height="360" maxFrameRate="30000/30030" par="16:9">
+    <AdaptationSet id="1" contentType="video" width="640" height="360" maxFrameRate="30000/22022" par="16:9">
       <EssentialProperty schemeIdUri="http://dashif.org/guidelines/trickmode" value="0"/>
       <Representation id="1" bandwidth="211545" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" frameRate="30000/30030" maxPlayoutRate="30" codingDependency="false">
         <BaseURL>bear-640x360-video-trick_play_factor_1.mp4</BaseURL>
@@ -18,7 +18,7 @@
           <Initialization range="0-858"/>
         </SegmentBase>
       </Representation>
-      <Representation id="2" bandwidth="211545" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" frameRate="30000/60060" maxPlayoutRate="60" codingDependency="false">
+      <Representation id="2" bandwidth="211545" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" frameRate="30000/22022" maxPlayoutRate="60" codingDependency="false">
         <BaseURL>bear-640x360-video-trick_play_factor_2.mp4</BaseURL>
         <SegmentBase indexRange="859-914" timescale="30000">
           <Initialization range="0-858"/>
diff --git a/packager/app/test/testdata/ec3-and-hls-single-segment-mp4-encrypted/output.m3u8 b/packager/app/test/testdata/ec3-and-hls-single-segment-mp4-encrypted/output.m3u8
index e9f0f91a991..02affa152e9 100644
--- a/packager/app/test/testdata/ec3-and-hls-single-segment-mp4-encrypted/output.m3u8
+++ b/packager/app/test/testdata/ec3-and-hls-single-segment-mp4-encrypted/output.m3u8
@@ -5,7 +5,7 @@
 
 #EXT-X-MEDIA:TYPE=AUDIO,URI="bear-640x360-ec3-audio.m3u8",GROUP-ID="default-audio-group",NAME="stream_0",AUTOSELECT=YES,CHANNELS="2"
 
-#EXT-X-STREAM-INF:BANDWIDTH=1174214,AVERAGE-BANDWIDTH=1061802,CODECS="avc1.64001e,ec-3",RESOLUTION=640x360,FRAME-RATE=9.990,AUDIO="default-audio-group"
+#EXT-X-STREAM-INF:BANDWIDTH=1174214,AVERAGE-BANDWIDTH=1061802,CODECS="avc1.64001e,ec-3",RESOLUTION=640x360,FRAME-RATE=29.970,AUDIO="default-audio-group"
 bear-640x360-ec3-video.m3u8
 
 #EXT-X-I-FRAME-STREAM-INF:BANDWIDTH=218705,AVERAGE-BANDWIDTH=159315,CODECS="avc1.64001e",RESOLUTION=640x360,URI="bear-640x360-ec3-video-iframe.m3u8"
diff --git a/packager/app/test/testdata/encryption-and-two-trick-plays/output.mpd b/packager/app/test/testdata/encryption-and-two-trick-plays/output.mpd
index 537a83b4509..591ce22a6d1 100644
--- a/packager/app/test/testdata/encryption-and-two-trick-plays/output.mpd
+++ b/packager/app/test/testdata/encryption-and-two-trick-plays/output.mpd
@@ -14,7 +14,7 @@
         </SegmentBase>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" width="640" height="360" maxFrameRate="30000/30030" par="16:9">
+    <AdaptationSet id="1" contentType="video" width="640" height="360" maxFrameRate="30000/22022" par="16:9">
       <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
@@ -26,7 +26,7 @@
           <Initialization range="0-1126"/>
         </SegmentBase>
       </Representation>
-      <Representation id="2" bandwidth="212297" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" frameRate="30000/60060" maxPlayoutRate="60" codingDependency="false">
+      <Representation id="2" bandwidth="212297" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" frameRate="30000/22022" maxPlayoutRate="60" codingDependency="false">
         <BaseURL>bear-640x360-video-trick_play_factor_2.mp4</BaseURL>
         <SegmentBase indexRange="1127-1182" timescale="30000">
           <Initialization range="0-1126"/>
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 bf21bef5d68..f126b6e4b27 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
@@ -2,22 +2,22 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" profiles="urn:mpeg:dash:profile:isoff-live:2011" minBufferTime="PT2S" type="dynamic" publishTime="some_time" availabilityStartTime="some_time" minimumUpdatePeriod="PT5S" timeShiftBufferDepth="PT1800S">
   <Period id="0" start="PT0S">
-    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="30000/1001" segmentAlignment="true" par="16:9">
-      <Representation id="0" bandwidth="974122" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1">
-        <SegmentTemplate timescale="30000" initialization="bear-640x360-video-init.mp4" media="bear-640x360-video-$Number$.m4s" startNumber="1">
+    <AdaptationSet id="0" contentType="text" segmentAlignment="true">
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
+      <Representation id="0" bandwidth="2024" 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="30030" r="1"/>
-            <S t="60060" d="22022"/>
+            <S t="0" d="1000" r="4"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="text" segmentAlignment="true">
-      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="1" bandwidth="2024" codecs="wvtt" mimeType="application/mp4">
-        <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
+    <AdaptationSet id="1" contentType="video" width="640" height="360" frameRate="30000/1001" segmentAlignment="true" par="16:9">
+      <Representation id="1" bandwidth="974122" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1">
+        <SegmentTemplate timescale="30000" initialization="bear-640x360-video-init.mp4" media="bear-640x360-video-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
-            <S t="0" d="1000" r="4"/>
+            <S t="0" d="30030" r="1"/>
+            <S t="60060" d="22022"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
diff --git a/packager/app/test/testdata/live-profile-and-encryption-and-mult-files/output.mpd b/packager/app/test/testdata/live-profile-and-encryption-and-mult-files/output.mpd
index a233a9be505..c5c9507a872 100644
--- a/packager/app/test/testdata/live-profile-and-encryption-and-mult-files/output.mpd
+++ b/packager/app/test/testdata/live-profile-and-encryption-and-mult-files/output.mpd
@@ -15,19 +15,19 @@
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
-      <Representation id="1" bandwidth="383593" codecs="avc1.64000d" mimeType="video/mp4" sar="1:1" width="320" height="180">
-        <SegmentTemplate timescale="30000" initialization="bear-320x180-video-init.mp4" media="bear-320x180-video-$Number$.m4s" startNumber="1">
+      <Representation id="1" bandwidth="978382" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" width="640" height="360">
+        <SegmentTemplate timescale="30000" initialization="bear-640x360-video-init.mp4" media="bear-640x360-video-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="30030" r="1"/>
-            <S t="60060" d="23023"/>
+            <S t="60060" d="22022"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
-      <Representation id="2" bandwidth="978382" codecs="avc1.64001e" mimeType="video/mp4" sar="1:1" width="640" height="360">
-        <SegmentTemplate timescale="30000" initialization="bear-640x360-video-init.mp4" media="bear-640x360-video-$Number$.m4s" startNumber="1">
+      <Representation id="2" bandwidth="383593" codecs="avc1.64000d" mimeType="video/mp4" sar="1:1" width="320" height="180">
+        <SegmentTemplate timescale="30000" initialization="bear-320x180-video-init.mp4" media="bear-320x180-video-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="30030" r="1"/>
-            <S t="60060" d="22022"/>
+            <S t="60060" d="23023"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
@@ -37,23 +37,23 @@
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
-      <Representation id="3" bandwidth="134015" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
+      <Representation id="3" bandwidth="134272" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
         <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
-        <SegmentTemplate timescale="44100" initialization="bear-320x180-audio-init.mp4" media="bear-320x180-audio-$Number$.m4s" startNumber="1">
+        <SegmentTemplate timescale="44100" initialization="bear-1280x720-audio-init.mp4" media="bear-1280x720-audio-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="45056"/>
             <S t="45056" d="44032"/>
-            <S t="89088" d="33792"/>
+            <S t="89088" d="31744"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
-      <Representation id="4" bandwidth="134272" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
+      <Representation id="4" bandwidth="134015" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
         <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
-        <SegmentTemplate timescale="44100" initialization="bear-1280x720-audio-init.mp4" media="bear-1280x720-audio-$Number$.m4s" startNumber="1">
+        <SegmentTemplate timescale="44100" initialization="bear-320x180-audio-init.mp4" media="bear-320x180-audio-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
             <S t="0" d="45056"/>
             <S t="45056" d="44032"/>
-            <S t="89088" d="31744"/>
+            <S t="89088" d="33792"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
diff --git a/packager/app/test/testdata/live-profile-with-webm/output.m3u8 b/packager/app/test/testdata/live-profile-with-webm/output.m3u8
index 491aaf1b4ac..b5c12fccb67 100644
--- a/packager/app/test/testdata/live-profile-with-webm/output.m3u8
+++ b/packager/app/test/testdata/live-profile-with-webm/output.m3u8
@@ -5,5 +5,5 @@
 
 #EXT-X-MEDIA:TYPE=AUDIO,URI="stream_0.m3u8",GROUP-ID="default-audio-group",NAME="stream_0",AUTOSELECT=YES,CHANNELS="2"
 
-#EXT-X-STREAM-INF:BANDWIDTH=556353,AVERAGE-BANDWIDTH=412719,CODECS="vp08.00.10.08.01.02.02.02.00,vorbis",RESOLUTION=640x360,FRAME-RATE=30.303,AUDIO="default-audio-group"
+#EXT-X-STREAM-INF:BANDWIDTH=556353,AVERAGE-BANDWIDTH=412719,CODECS="vp08.00.10.08.01.02.02.02.00,vorbis",RESOLUTION=640x360,FRAME-RATE=29.412,AUDIO="default-audio-group"
 stream_1.m3u8
diff --git a/packager/app/test/testdata/live-profile-with-webm/output.mpd b/packager/app/test/testdata/live-profile-with-webm/output.mpd
index acfdd31f70c..cf2f3ec4501 100644
--- a/packager/app/test/testdata/live-profile-with-webm/output.mpd
+++ b/packager/app/test/testdata/live-profile-with-webm/output.mpd
@@ -14,7 +14,7 @@
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" width="640" height="360" frameRate="1000000/33000" segmentAlignment="true" par="16:9">
+    <AdaptationSet id="1" contentType="video" width="640" height="360" frameRate="1000000/34000" segmentAlignment="true" par="16:9">
       <Representation id="1" bandwidth="472384" codecs="vp8" mimeType="video/webm" sar="1:1">
         <SegmentTemplate timescale="1000000" initialization="bear-640x360-video-init.webm" media="bear-640x360-video-$Number$.webm" startNumber="1">
           <SegmentTimeline>
diff --git a/packager/app/test/testdata/opus-vp9-mp4-with-encryption/output.mpd b/packager/app/test/testdata/opus-vp9-mp4-with-encryption/output.mpd
index 283e00ab9eb..1a8bab81124 100644
--- a/packager/app/test/testdata/opus-vp9-mp4-with-encryption/output.mpd
+++ b/packager/app/test/testdata/opus-vp9-mp4-with-encryption/output.mpd
@@ -15,7 +15,7 @@
         </SegmentBase>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" width="320" height="240" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="1" contentType="video" width="320" height="240" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
       <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
diff --git a/packager/app/test/testdata/vp8-mp4-with-encryption/output.mpd b/packager/app/test/testdata/vp8-mp4-with-encryption/output.mpd
index 1fe1015889a..a089915cad0 100644
--- a/packager/app/test/testdata/vp8-mp4-with-encryption/output.mpd
+++ b/packager/app/test/testdata/vp8-mp4-with-encryption/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" xmlns:cenc="urn:mpeg:cenc:2013" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7360000610351562S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
       <ContentProtection value="cenc" schemeIdUri="urn:mpeg:dash:mp4protection:2011" cenc:default_KID="31323334-3536-3738-3930-313233343536"/>
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
diff --git a/packager/app/test/testdata/vp8-webm/output.mpd b/packager/app/test/testdata/vp8-webm/output.mpd
index 777ddf60cfb..fbd60e85d7f 100644
--- a/packager/app/test/testdata/vp8-webm/output.mpd
+++ b/packager/app/test/testdata/vp8-webm/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7360000610351562S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
       <Representation id="0" bandwidth="472384" codecs="vp8" mimeType="video/webm" sar="1:1">
         <BaseURL>bear-640x360-video.webm</BaseURL>
         <SegmentBase indexRange="289-338" timescale="1000000" presentationTimeOffset="26000">
diff --git a/packager/app/test/testdata/vp9-webm-with-blockgroup/output.mpd b/packager/app/test/testdata/vp9-webm-with-blockgroup/output.mpd
index cbd3526f737..18e61dd25f4 100644
--- a/packager/app/test/testdata/vp9-webm-with-blockgroup/output.mpd
+++ b/packager/app/test/testdata/vp9-webm-with-blockgroup/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7360000610351562S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="320" height="240" frameRate="1000000/33000" subsegmentAlignment="true" par="4:3">
+    <AdaptationSet id="0" contentType="video" width="320" height="240" frameRate="1000000/34000" subsegmentAlignment="true" par="4:3">
       <Representation id="0" bandwidth="196039" codecs="vp09.00.20.08.01.02.02.02.00" mimeType="video/webm" sar="1:1">
         <BaseURL>bear-vp9-blockgroup-video.webm</BaseURL>
         <SegmentBase indexRange="302-320" timescale="1000000">
diff --git a/packager/app/test/testdata/vp9-webm/output.mpd b/packager/app/test/testdata/vp9-webm/output.mpd
index 5cc8a6deda0..8db6e15644c 100644
--- a/packager/app/test/testdata/vp9-webm/output.mpd
+++ b/packager/app/test/testdata/vp9-webm/output.mpd
@@ -11,7 +11,7 @@
         </SegmentBase>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="video" width="320" height="240" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="1" contentType="video" width="320" height="240" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
       <Representation id="1" bandwidth="225727" codecs="vp09.00.20.08.01.02.02.02.00" mimeType="video/webm" sar="427:320">
         <BaseURL>bear-320x240-vp9-opus-video.webm</BaseURL>
         <SegmentBase indexRange="302-350" timescale="1000000" presentationTimeOffset="37000">
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 e51298416e6..e357f76f8e9 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
@@ -11,24 +11,24 @@
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="text" segmentAlignment="true">
-      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="1" bandwidth="1912" codecs="wvtt" mimeType="application/mp4">
-        <SegmentTemplate timescale="1000" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="1">
+    <AdaptationSet id="1" contentType="audio" segmentAlignment="true">
+      <Representation id="1" bandwidth="133929" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
+        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
+        <SegmentTemplate timescale="44100" initialization="bear-640x360-audio-init.mp4" media="bear-640x360-audio-$Number$.m4s" startNumber="1">
           <SegmentTimeline>
-            <S t="0" d="1000" r="1"/>
-            <S t="2000" d="1"/>
+            <S t="0" d="45056"/>
+            <S t="45056" d="43008"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="2" contentType="audio" segmentAlignment="true">
-      <Representation id="2" bandwidth="133929" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
-        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
-        <SegmentTemplate timescale="44100" initialization="bear-640x360-audio-init.mp4" media="bear-640x360-audio-$Number$.m4s" startNumber="1">
+    <AdaptationSet id="2" contentType="text" segmentAlignment="true">
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
+      <Representation id="2" bandwidth="1912" 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="45056"/>
-            <S t="45056" d="43008"/>
+            <S t="0" d="1000" r="1"/>
+            <S t="2000" d="1"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
@@ -44,22 +44,22 @@
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="1" contentType="text" segmentAlignment="true">
-      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
-      <Representation id="1" bandwidth="2024" codecs="wvtt" mimeType="application/mp4">
-        <SegmentTemplate timescale="1000" presentationTimeOffset="2001" initialization="bear-english-text-init.mp4" media="bear-english-text-$Number$.m4s" startNumber="4">
+    <AdaptationSet id="1" contentType="audio" segmentAlignment="true">
+      <Representation id="1" bandwidth="108086" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
+        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
+        <SegmentTemplate timescale="44100" presentationTimeOffset="88288" initialization="bear-640x360-audio-init.mp4" media="bear-640x360-audio-$Number$.m4s" startNumber="3">
           <SegmentTimeline>
-            <S t="2001" d="1000" r="2"/>
+            <S t="88064" d="32768"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
     </AdaptationSet>
-    <AdaptationSet id="2" contentType="audio" segmentAlignment="true">
-      <Representation id="2" bandwidth="108086" codecs="mp4a.40.2" mimeType="audio/mp4" audioSamplingRate="44100">
-        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
-        <SegmentTemplate timescale="44100" presentationTimeOffset="88288" initialization="bear-640x360-audio-init.mp4" media="bear-640x360-audio-$Number$.m4s" startNumber="3">
+    <AdaptationSet id="2" contentType="text" segmentAlignment="true">
+      <Role schemeIdUri="urn:mpeg:dash:role:2011" value="subtitle"/>
+      <Representation id="2" bandwidth="2024" 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="88064" d="32768"/>
+            <S t="2001" d="1000" r="2"/>
           </SegmentTimeline>
         </SegmentTemplate>
       </Representation>
diff --git a/packager/app/test/testdata/webm-subsample-encryption/output.mpd b/packager/app/test/testdata/webm-subsample-encryption/output.mpd
index 69140f2d58e..0bc203a8f6c 100644
--- a/packager/app/test/testdata/webm-subsample-encryption/output.mpd
+++ b/packager/app/test/testdata/webm-subsample-encryption/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" xmlns:cenc="urn:mpeg:cenc:2013" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7690000534057617S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="320" height="180" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" width="320" height="180" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b" cenc:default_KID="31323334-3536-3738-3930-313233343536">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
diff --git a/packager/app/test/testdata/webm-vp9-full-sample-encryption/output.mpd b/packager/app/test/testdata/webm-vp9-full-sample-encryption/output.mpd
index 69140f2d58e..0bc203a8f6c 100644
--- a/packager/app/test/testdata/webm-vp9-full-sample-encryption/output.mpd
+++ b/packager/app/test/testdata/webm-vp9-full-sample-encryption/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" xmlns:cenc="urn:mpeg:cenc:2013" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7690000534057617S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="320" height="180" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" width="320" height="180" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b" cenc:default_KID="31323334-3536-3738-3930-313233343536">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
diff --git a/packager/app/test/testdata/webm-with-encryption/output.mpd b/packager/app/test/testdata/webm-with-encryption/output.mpd
index c06555905b4..de6bb6106f5 100644
--- a/packager/app/test/testdata/webm-with-encryption/output.mpd
+++ b/packager/app/test/testdata/webm-with-encryption/output.mpd
@@ -2,7 +2,7 @@
 <!--Generated with https://github.com/google/shaka-packager version <tag>-<hash>-<test>-->
 <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" xmlns:cenc="urn:mpeg:cenc:2013" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT2.7360000610351562S">
   <Period id="0">
-    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/33000" subsegmentAlignment="true" par="16:9">
+    <AdaptationSet id="0" contentType="video" width="640" height="360" frameRate="1000000/34000" subsegmentAlignment="true" par="16:9">
       <ContentProtection schemeIdUri="urn:uuid:1077efec-c0b2-4d02-ace3-3c1e52e2fb4b" cenc:default_KID="31323334-3536-3738-3930-313233343536">
         <cenc:pssh>AAAANHBzc2gBAAAAEHfv7MCyTQKs4zweUuL7SwAAAAExMjM0NTY3ODkwMTIzNDU2AAAAAA==</cenc:pssh>
       </ContentProtection>
diff --git a/packager/media/formats/mp4/segmenter.h b/packager/media/formats/mp4/segmenter.h
index febdfb1fa1e..28fe5b04b4a 100644
--- a/packager/media/formats/mp4/segmenter.h
+++ b/packager/media/formats/mp4/segmenter.h
@@ -98,7 +98,7 @@ class Segmenter {
 
   /// @return The sample duration in the timescale of the media.
   ///         Returns 0 if no samples are added yet.
-  uint32_t sample_duration() const { return sample_durations_[1]; }
+  int64_t sample_duration() const { return sample_durations_[1]; }
 
  protected:
   /// Update segmentation progress using ProgressListener.
@@ -144,7 +144,7 @@ class Segmenter {
   ProgressListener* progress_listener_ = nullptr;
   uint64_t progress_target_ = 0u;
   uint64_t accumulated_progress_ = 0u;
-  uint32_t sample_durations_[2] = {0, 0};
+  size_t sample_durations_[2] = {0, 0};
   uint32_t num_samples_ = 0u;
   std::vector<uint64_t> stream_durations_;
   std::vector<KeyFrameInfo> key_frame_infos_;
diff --git a/packager/media/formats/webm/segmenter.cc b/packager/media/formats/webm/segmenter.cc
index 85c3101abe9..ba6f8f7130f 100644
--- a/packager/media/formats/webm/segmenter.cc
+++ b/packager/media/formats/webm/segmenter.cc
@@ -165,7 +165,7 @@ Status Segmenter::AddSample(const MediaSample& source_sample) {
     sample_durations_[num_samples_] = sample->duration();
     if (num_samples_ == 0)
       first_timestamp_ = sample->pts();
-    else 
+    else if (muxer_listener_)
       muxer_listener_->OnSampleDurationReady(sample_durations_[num_samples_]);
     num_samples_++;
   }
diff --git a/packager/media/formats/webm/segmenter.h b/packager/media/formats/webm/segmenter.h
index 2ab0bcc21fa..d137b0283c5 100644
--- a/packager/media/formats/webm/segmenter.h
+++ b/packager/media/formats/webm/segmenter.h
@@ -139,7 +139,7 @@ class Segmenter {
   uint64_t progress_target_ = 0;
   uint64_t accumulated_progress_ = 0;
   uint64_t first_timestamp_ = 0;
-  int64_t sample_durations_[2] = {0, 0};
+  size_t sample_durations_[2] = {0, 0};
   int64_t num_samples_ = 0;
   // The position (in bytes) of the start of the Segment payload in the init
   // file.  This is also the size of the header before the SeekHead.