[FFmpeg-user] Issue in libavformat/dashdec.c and string to time conversion.

[ramon]

The  get_duration_insec() function form libavformat/dashdec.c not support
the "Y" (year) option.
This is used in some cases. For example in the manifest form dashif.org
https://livesim.dashif.org/livesim/testpic_2s/Manifest.mpd that uses
"P100Y" in "minimumUpdatePeriod" attribute:

<?xml version="1.0" encoding="utf-8"?>
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance"
availabilityStartTime="1970-01-01T00:00:00Z" id="Config part of url maybe?"
maxSegmentDuration="PT2S" minBufferTime="PT2S" minimumUpdatePeriod="P100Y"
profiles="urn:mpeg:dash:profile:isoff-live:2011,
http://dashif.org/guidelines/dash-if-simple"
publishTime="2023-02-12T18:20:09Z" timeShiftBufferDepth="PT5M"
type="dynamic" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011
DASH-MPD.xsd">
   <ProgramInformation>
      <Title>Media Presentation Description from DASH-IF live
simulator</Title>
   </ProgramInformation>
   <BaseURL>
https://livesim.dashif.org/livesim/sts_1676226009/sid_355d4a19/testpic_2s/
</BaseURL>
<Period id="p0" start="PT0S">
      <AdaptationSet contentType="audio" lang="en" mimeType="audio/mp4"
segmentAlignment="true" startWithSAP="1">
         <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main" />
         <SegmentTemplate duration="2"
initialization="$RepresentationID$/init.mp4"
media="$RepresentationID$/$Number$.m4s" startNumber="0" />
         <Representation audioSamplingRate="48000" bandwidth="48000"
codecs="mp4a.40.2" id="A48">
            <AudioChannelConfiguration
schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011"
value="2" />
         </Representation>
      </AdaptationSet>
      <AdaptationSet contentType="video" maxFrameRate="60/2"
maxHeight="360" maxWidth="640" mimeType="video/mp4" minHeight="360"
minWidth="640" par="16:9" segmentAlignment="true" startWithSAP="1">
         <Role schemeIdUri="urn:mpeg:dash:role:2011" value="main" />
         <SegmentTemplate duration="2"
initialization="$RepresentationID$/init.mp4"
media="$RepresentationID$/$Number$.m4s" startNumber="0" />
         <Representation bandwidth="300000" codecs="avc1.64001e"
frameRate="60/2" height="360" id="V300" sar="1:1" width="640" />
      </AdaptationSet>
   </Period>
</MPD>