DASH: Segment timeline start number is wrong

There appears to be a regression in the use of startNumber inheritance for the segment timeline in DASH playback. Attempting to play any DASH MPD linear content that doesn't have a segmentTemplate startNumber close to 1 results in invalid segment requests. These requests use a media segment template

$Number$

of (1 + segment offset) rather than the expected (startNumber + segment offset).

No issue on 3.0.1 First seen on 3.0.11 Tested nightly build https://artifacts.videolan.org/vlc-3.0/nightly-macos/20200902-0637/ and found it to still have the issue.

added Component::Input: network streams label

provide url

Apologies I don't have any live streams available. Hopefully this will suffice.

Below is an example dynamic manifest that will reproduce the request issue. Attempting to open this manifest will result in a request for

test-stream/repid-0-frag-3.mp4

The start number of the that representation segment timeline is "798742550". The expected request would be

test-stream/repid-0-frag-798742553.mp4

Example manifest

<?xml version="1.0" encoding="UTF-8"?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" type="dynamic" publishTime="2020-09-02T21:37:03.448Z">
   <Period start="PT173402.036S" id="46041">
    <AdaptationSet mimeType="video/mp4" segmentAlignment="true" subsegmentAlignment="true" startWithSAP="1" subsegmentStartsWithSAP="1" bitstreamSwitching="true">
      <Representation id="0" bandwidth="100000" codecs="avc1.4d401e" width="640" height="480" frameRate="30000/1001"/>
      <SegmentTemplate media="test-stream/repid-$RepresentationID$-frag-$Number$.mp4" timescale="90000" startNumber="798742550" presentationTimeOffset="2402">
        <SegmentTimeline>
          <S t="5202061" d="115"/>
          <S t="5202176" d="120" r="4"/>
        </SegmentTimeline>
      </SegmentTemplate>
    </AdaptationSet>
  </Period>
</MPD>

Spec

https://dashif-documents.azurewebsites.net/Guidelines-TimingModel/master/Guidelines-TimingModel.html#addressing-explicit

If using $Number$ addressing, the number of the first segment reference is defined by SegmentTemplate@startNumber (default value 1) ([DASH] 5.3.9.5.3).

changed title from Segment timeline start number is wrong to DASH: Segment timeline start number is wrong

eb1e8a60

check with nightly builds

added Component::Demuxers label and removed Component::Input: network streams label

added Severity::normal label

changed milestone to %3.0.x maintenance

I can't seem to find nightly build eb1e8a6082791a97e371199884c98d00108b43de for MacOS

Would you mind providing a link? I tried with the latest nightly in https://artifacts.videolan.org/vlc-3.0/nightly-macos/20200917-0638/ but still see the issue.

Replying to [comment:6 Rocky]:

I can't seem to find nightly build eb1e8a6082791a97e371199884c98d00108b43de for MacOS

Would you mind providing a link? I tried with the latest nightly in https://artifacts.videolan.org/vlc-3.0/nightly-macos/20200917-0638/ but still see the issue.

4.0 nb. there's no backport until confirmation

Working on latest 4.0 nb.

Fixed in 3.0.12

closed

added Component::Demux: Adaptive label and removed Component::Demuxers label

changed milestone to %3.0.12

added Status::fixed label