Live Streaming MPD Contain Misalignment Segment Start Time

Live streaming (MPEG-DASH) provide MPD file that contain different segment start time.

I am streaming 9 streams of 3 different resolutions (27 streams total) and i am using Wowza packager.

My MPD file contain 3 adaptation sets and each adaptation set contain a SegmentTimeline (List of segments)-

The first segment have “t” (time) and “d” (duration).

So, totally we have 3 first-segments with “t” attribute (for each adaptation set).

the value of one of them is not equal to the 2 others.

Here is my MPD file:

<?xml version="1.0" encoding="UTF-8"?>
<MPD xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="urn:mpeg:dash:schema:mpd:2011"
     xmlns:xlink="http://www.w3.org/1999/xlink"
     xsi:schemaLocation="urn:mpeg:DASH:schema:MPD:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd"
     profiles="urn:mpeg:dash:profile:isoff-live:2011"
     type="dynamic"
     minimumUpdatePeriod="PT1.489S" 
     publishTime="2019-06-06T12:55:32Z" 
     availabilityStartTime="2019-06-06T12:15:43Z" 
     timeShiftBufferDepth="PT25.0S"
     suggestedPresentationDelay="PT1.0S" 
     minBufferTime="PT6.0S">
<ProgramInformation>
    <Title>camera1.smil</Title>
</ProgramInformation>
<Location>http://...:1935/..../smil:camera1.smil/manifest_w1997958089.mpd</Location>
<Period id="0" start="PT0.0S">
    <AdaptationSet id="0" group="1" mimeType="video/mp4" width="3200" height="640" par="1:1" frameRate="30" segmentAlignment="true" startWithSAP="1" subsegmentAlignment="true" subsegmentStartsWithSAP="1">
        <SegmentTemplate timescale="90000" media="chunk_ctvideo_cfm4s_rid$RepresentationID$_cs$Time$_w1997958089_mpd.m4s" initialization="chunk_ctvideo_cfm4s_rid$RepresentationID$_cinit_w1997958089_mpd.m4s">
            <SegmentTimeline>
                <S t="212758470" d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
            </SegmentTimeline>
        </SegmentTemplate>
        <Representation id="p0va0br3000000" codecs="avc1.640033" sar="1:1" bandwidth="3000000" />
        <Representation id="p0va0br3100000" codecs="avc1.640033" sar="1:1" bandwidth="3100000" />
        <Representation id="p0va0br3500000" codecs="avc1.640033" sar="1:1" bandwidth="3500000" />
        <Representation id="p0va0br4200000" codecs="avc1.640033" sar="1:1" bandwidth="4200000" />
        <Representation id="p0va0br4300000" codecs="avc1.640033" sar="1:1" bandwidth="4300000" />
        <Representation id="p0va0br4150000" codecs="avc1.640033" sar="1:1" bandwidth="4150000" />
        <Representation id="p0va0br3400000" codecs="avc1.640033" sar="1:1" bandwidth="3400000" />
        <Representation id="p0va0br2900000" codecs="avc1.640033" sar="1:1" bandwidth="2900000" />
        <Representation id="p0va0br2800000" codecs="avc1.640033" sar="1:1" bandwidth="2800000" />
    </AdaptationSet>
    <AdaptationSet id="1" group="1" mimeType="video/mp4" width="3200" height="320" par="1:1" frameRate="30" segmentAlignment="true" startWithSAP="1" subsegmentAlignment="true" subsegmentStartsWithSAP="1">
        <SegmentTemplate timescale="90000" media="chunk_ctvideo_cfm4s_rid$RepresentationID$_cs$Time$_w1997958089_mpd.m4s" initialization="chunk_ctvideo_cfm4s_rid$RepresentationID$_cinit_w1997958089_mpd.m4s">
            <SegmentTimeline>
                <S t="212713470" d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
            </SegmentTimeline>
        </SegmentTemplate>
        <Representation id="p0va1br1310000" codecs="avc1.640033" sar="1:1" bandwidth="1310000" />
        <Representation id="p0va1br1320000" codecs="avc1.640033" sar="1:1" bandwidth="1320000" />
        <Representation id="p0va1br1340000" codecs="avc1.640033" sar="1:1" bandwidth="1340000" />
        <Representation id="p0va1br1840000" codecs="avc1.640033" sar="1:1" bandwidth="1840000" />
        <Representation id="p0va1br1850000" codecs="avc1.640033" sar="1:1" bandwidth="1850000" />
        <Representation id="p0va1br1860000" codecs="avc1.640033" sar="1:1" bandwidth="1860000" />
        <Representation id="p0va1br1870000" codecs="avc1.640033" sar="1:1" bandwidth="1870000" />
        <Representation id="p0va1br1380000" codecs="avc1.640033" sar="1:1" bandwidth="1380000" />
        <Representation id="p0va1br1390000" codecs="avc1.640033" sar="1:1" bandwidth="1390000" />
    </AdaptationSet>
    <AdaptationSet id="2" group="1" mimeType="video/mp4" width="3200" height="160" par="1:1" frameRate="30" segmentAlignment="true" startWithSAP="1" subsegmentAlignment="true" subsegmentStartsWithSAP="1">
        <SegmentTemplate timescale="90000" media="chunk_ctvideo_cfm4s_rid$RepresentationID$_cs$Time$_w1997958089_mpd.m4s" initialization="chunk_ctvideo_cfm4s_rid$RepresentationID$_cinit_w1997958089_mpd.m4s">
            <SegmentTimeline>
                <S t="212758470" d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
                <S d="45000"/>
            </SegmentTimeline>
        </SegmentTemplate>
        <Representation id="p0va2br151000" codecs="avc1.640033" sar="1:1" bandwidth="151000" />
        <Representation id="p0va2br252000" codecs="avc1.640033" sar="1:1" bandwidth="252000" />
        <Representation id="p0va2br483000" codecs="avc1.640033" sar="1:1" bandwidth="483000" />
        <Representation id="p0va2br584000" codecs="avc1.640033" sar="1:1" bandwidth="584000" />
        <Representation id="p0va2br585000" codecs="avc1.640033" sar="1:1" bandwidth="585000" />
        <Representation id="p0va2br586000" codecs="avc1.640033" sar="1:1" bandwidth="586000" />
        <Representation id="p0va2br487000" codecs="avc1.640033" sar="1:1" bandwidth="487000" />
        <Representation id="p0va2br258000" codecs="avc1.640033" sar="1:1" bandwidth="258000" />
        <Representation id="p0va2br159000" codecs="avc1.640033" sar="1:1" bandwidth="159000" />
    </AdaptationSet>
</Period>
<UTCTiming schemeIdUri="urn:mpeg:dash:utc:direct:2014" value="2019-06-06T12:55:32Z"/>
</MPD>

You can see the misalignment:

<code><S t="212758470" d="45000"/>

<code><S t="212713470" d="45000"/>

<code><S t="212758470" d="45000"/>

My questions is:

  • This is valid situation?
  • If yes, What the reason for this misalignment?
  • If no, How can I fix it?

Please note that this misalignment not happened in all MPD’s, its happened sometimes.

My goal is getting exactly same SegmentTemplate for each adaptation set.

To assist you with such an advanced workflow, tech support needs to have you submit a support ticket. They can’t debug this through the forums and truly need access to all of your log files. Thank you!

https://www.wowza.com/support/open-ticket