DASH Multi-Period / multi-codec issue in Firefox

[rogerpales]

Have you read the FAQ and checked for duplicate open issues?
yes

If the problem is related to FairPlay, have you read the tutorial?

What version of Shaka Player are you using?
v4.8.7

Can you reproduce the issue with our latest release version?
yes

Can you reproduce the issue with the latest code from main?
yes

Are you using the demo app or your own custom app?
both

If custom app, can you reproduce the issue using our demo app?

What browser and OS are you using?
Firefox both MacOS / Windows

For embedded devices (smart TVs, etc.), what model and firmware version are you using?

What are the manifest and license server URIs?
Tweaked https://reference.dashif.org/dash.js/v4.4.0/samples/multiperiod/vod.html

<?xml version="1.0" encoding="utf-8"?>
<!--Single content continuing at the period boundary.-->
<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" minBufferTime="PT1.500000S" type="static" mediaPresentationDuration="PT0H9M54.00S" profiles="urn:mpeg:dash:profile:isoff-live:2011,http://dashif.org/guidelines/dash264">
  <Period id="0" duration="PT250S">
    <BaseURL>https://dash.akamaized.net/dash264/TestCases/5a/nomor/</BaseURL>
    <AdaptationSet segmentAlignment="true" maxWidth="1280" maxHeight="720" maxFrameRate="24" par="16:9">
      <Representation id="1" mimeType="video/mp4" codecs="avc1.4d401f" width="1280" height="720" frameRate="24" sar="1:1" startWithSAP="1" bandwidth="980104">
        <SegmentTemplate timescale="12288" presentationTimeOffset="1024" duration="24576" media="BBB_720_1M_video_$Number$.mp4" startNumber="1" initialization="BBB_720_1M_video_init.mp4" />
      </Representation>
    </AdaptationSet>
    <AdaptationSet segmentAlignment="true">
      <Representation id="4" mimeType="audio/mp4" codecs="mp4a.40.29" audioSamplingRate="48000" startWithSAP="1" bandwidth="33434">
        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2" />
        <SegmentTemplate timescale="48000" duration="94175" media="BBB_32k_$Number$.mp4" startNumber="1" initialization="BBB_32k_init.mp4" />
      </Representation>
    </AdaptationSet>
  </Period>
  <Period id="1" duration="PT344S">
    <BaseURL>https://dash.akamaized.net/dash264/TestCases/5a/nomor/</BaseURL>
    <AdaptationSet segmentAlignment="true" maxWidth="1280" maxHeight="720" maxFrameRate="24" par="16:9">
      <Representation id="1" mimeType="video/mp4" codecs="avc3.4d401f" width="1280" height="720" frameRate="24" sar="1:1" startWithSAP="1" bandwidth="980105">
        <SegmentTemplate timescale="12288" presentationTimeOffset="3073024" duration="24576" media="BBB_720_1M_video_$Number$.mp4" startNumber="126" initialization="BBB_720_1M_video_init.mp4" />
      </Representation>
    </AdaptationSet>
    <AdaptationSet segmentAlignment="true">
      <Representation id="4" mimeType="audio/mp4" codecs="mp4a.40.29" audioSamplingRate="48000" startWithSAP="1" bandwidth="33435">
        <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2" />
        <SegmentTemplate timescale="48000" presentationTimeOffset="12000000" duration="94175" media="BBB_32k_$Number$.mp4" startNumber="128" initialization="BBB_32k_init.mp4" />
      </Representation>
    </AdaptationSet>
  </Period>
</MPD>

What configuration are you using? What is the output of player.getConfiguration()?

What did you do?
Try to play a multiperiod dash in Firefox/ShakaDemo with different AS codecs in between periods.

What did you expect to happen?
To load and play.

What actually happened?
An exception is raised "res is null", see att. screenshot.

Are you planning send a PR to fix it?
Yes.