When using dynamic packaging, the HLS stream isn't returning the audio tracks correctly if there are 2 present. e.g. via the Azure Portal: upload and encode a mp4 video (output is audio track and video tracks) add an audio description track so there are now 2 audio tracks edit the manifest .ism to adjust the track name for the video audio track and set the audio track to not be the default track Use videoJS or Azure media player to play the video (HLS or DASH), and there are 2 main issues: HLS and DASH ignore the display name for the video audio track. (e.g. it should be 'English' not 'aac_eng_2_128038_2_1' HLS switches the order of the audio tracks, and sets the descriptive audio as the default track 'DEFAULT=YES' #EXTM3U #EXT-X-VERSION:7 #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="aac_eng_2_128038_2_1",LANGUAGE="eng",CHANNELS="2",URI="QualityLevels(128038)/Manifest(aac_eng_2_128038_2_1,format=m3u8-cmaf)" #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English (Audio Description)",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,CHARACTERISTICS="public.accessibility.describes-video",CHANNELS="2",URI="QualityLevels(317324)/Manifest(audio_eng_adl,format=m3u8-cmaf)"**

Thanks for the follow-up and update. It seems like you are trying to change the order of the audio elements in the .ism file, but it is not making any difference. You mentioned that you have not edited the english.ismc file so far. The english.ismc file is the client manifest file that contains the info about the media files and their bitrates. Yes, when you create a streaming locator for the asset, you may use the playback URL provided for HLS or DASH, and you don't have control over the output (EXT-X-MEDIA) tags. The URL you provided looks like this for HLS : https://[name].streaming.media.azure.net/[guid]/english.ism/manifest(format=m3u8-cmaf) . Just to isolate, you may try editing the english.ismc file for changing the order of the audio elements. As you mentioned, you may try creating a new streaming locator and see if it makes any difference. Kindly let us know, if the issue persists, I'll follow-up further with you offline.

Audio description track is always set as the default audio track

Anonymous

When using dynamic packaging, the HLS stream isn't returning the audio tracks correctly if there are 2 present.

e.g. via the Azure Portal:

upload and encode a mp4 video (output is audio track and video tracks)
add an audio description track so there are now 2 audio tracks
edit the manifest .ism to adjust the track name for the video audio track and set the audio track to not be the default track

Use videoJS or Azure media player to play the video (HLS or DASH), and there are 2 main issues:

HLS and DASH ignore the display name for the video audio track. (e.g. it should be 'English' not 'aac_eng_2_128038_2_1'
HLS switches the order of the audio tracks, and sets the descriptive audio as the default track 'DEFAULT=YES'

#EXTM3U
#EXT-X-VERSION:7

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="aac_eng_2_128038_2_1",LANGUAGE="eng",CHANNELS="2",URI="QualityLevels(128038)/Manifest(aac_eng_2_128038_2_1,format=m3u8-cmaf)"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English (Audio Description)",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,CHARACTERISTICS="public.accessibility.describes-video",CHANNELS="2",URI="QualityLevels(317324)/Manifest(audio_eng_adl,format=m3u8-cmaf)"**

ajkuma 24,396 Reputation points Microsoft Employee

2023-06-08T08:12:59.6366667+00:00
Julia Kerr, From my understanding of the issue, based on the info you provided, it seems that the display name for the video audio track is not being recognized correctly, and the descriptive audio track is being set as the default track.

I understand you have set the manifest and adjusted the tags appropriately. Just to clarify, how exactly are you generating and editing the manifest?

You may try to modify the manifest file to explicitly set the display name for the audio tracks and to specify which track should be the default track, the following way', and see if it helps.

1. Open the manifest file in a text editor.

2. Locate the EXT-X-MEDIA tags for the audio tracks, and try modifying this way to see if it helps.

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English",LANGUAGE="eng",CHANNELS="2",URI="QualityLevels(128038)/Manifest(aac_eng_2_128038_2_1,format=m3u8-cmaf)" #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="Audio Description",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,CHARACTERISTICS="public.accessibility.describes-video",CHANNELS="2",URI="QualityLevels(317324)/Manifest(audio_eng_adl,format=m3u8-cmaf)"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English",LANGUAGE="eng",CHANNELS="2",URI="QualityLevels(128038)/Manifest(aac_eng_2_128038_2_1,format=m3u8-cmaf)" #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="Audio Description",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,CHARACTERISTICS="public.accessibility.describes-video",CHANNELS="2",URI="QualityLevels(317324)/Manifest(audio_eng_adl,format=m3u8-cmaf)"

Also, please take a look at this discussion thread - on swapping order of <audio/> entry.

Kindly let us know, I'll follow-up further. Thanks!

Anonymous

Hello,

I've configured everything 100% via the Azure Portal. In the portal, I'm accessing the storage container linked to in the 'Files on Storage' tab where I edit the .ism file. This .ism file was autogenerated when the video mp4 was encoded. I tried changing the order of the audio elements in the .ism but it didn't make any difference but i will retry this with a new streaming locator. I've not edited english.ismc so far. e.g, english.ism:

<?xml version="1.0" encoding="utf-8"?>
<smil xmlns="http://www.w3.org/2001/SMIL20/Language">
  <head>
    <meta name="clientManifestRelativePath" content="english.ismc" />
    <meta name="formats" content="mp4-v3" />
  </head>
  <body>
    <switch>
      <audio src="english_640x360_AACAudio_243.mp4" systemBitrate="128038" systemLanguage="eng">
        <param name="systemBitrate" value="128038" valuetype="data" />
        <param name="trackID" value="2" valuetype="data" />
        <param name="trackName" value="aac_eng_2_128038_2_1" valuetype="data" />
		<param name="displayName" value="English" valuetype="data" />
        <param name="systemLanguage" value="eng" valuetype="data" />
        <param name="trackIndex" value="english_640x360_AACAudio_243_2.mpi" valuetype="data" />
      </audio>
      <video etc>
      <textstream  etc>
      <audio src="english-ad.mp4" systemBitrate="128037" systemLanguage="eng">
        <param name="trackIndex" value="english-ad_2.mpi" valuetype="data" />
        <param name="systemLanguage" value="eng" valuetype="data" />
        <param name="role" value="alternate" valuetype="data" />
        <param name="systemBitrate" value="128037" valuetype="data" />
        <param name="displayName" value="English (Audio Description)" valuetype="data" />
        <param name="accessibility" value="description" valuetype="data" />
        <param name="hlsCharacteristic" value="public.accessibility.describes-video" valuetype="data" />
        <param name="trackID" value="2" valuetype="data" />
        <param name="trackName" value="audio_eng_ad" valuetype="data" />
        <param name="armId" value="ad" valuetype="data" />
      </audio>
    </switch>
  </body>
</smil>

I then create a streaming locator for the asset, and use the playback url provided for HLS or DASH so i don't have control over the output (EXT-X-MEDIA) tags as far as I'm aware?

e.g.

url looks like this for HLS

https://[name].streaming.media.azure.net/[guid]/english.ism/manifest(format=m3u8-cmaf)

and it returns

#EXTM3U

#EXT-X-VERSION:7

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="aac_eng_2_128038_2_1",LANGUAGE="eng",CHANNELS="2",URI="QualityLevels(128038)/Manifest(aac_eng_2_128038_2_1,format=m3u8-cmaf)"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="audio",NAME="English (Audio Description)",LANGUAGE="eng",DEFAULT=YES,AUTOSELECT=YES,CHARACTERISTICS="public.accessibility.describes-video",CHANNELS="2",URI="QualityLevels(128037)/Manifest(audio_eng_ad,format=m3u8-cmaf)"

etc

ajkuma 24,396 Reputation points Microsoft Employee

2023-06-15T19:34:22.7433333+00:00

Julia Kerr, Just checking in to see if you had got a chance to see the previous response. Please share the requested/more info to help you better.

1 answer

ajkuma 24,396 Reputation points Microsoft Employee

2023-06-09T06:41:20.4533333+00:00

Thanks for the follow-up and update.

It seems like you are trying to change the order of the audio elements in the .ism file, but it is not making any difference. You mentioned that you have not edited the english.ismc file so far. The english.ismc file is the client manifest file that contains the info about the media files and their bitrates.

Yes, when you create a streaming locator for the asset, you may use the playback URL provided for HLS or DASH, and you don't have control over the output (EXT-X-MEDIA) tags. The URL you provided looks like this for HLS: https://[name].streaming.media.azure.net/[guid]/english.ism/manifest(format=m3u8-cmaf).

Just to isolate, you may try editing the english.ismc file for changing the order of the audio elements. As you mentioned, you may try creating a new streaming locator and see if it makes any difference.

Kindly let us know, if the issue persists, I'll follow-up further with you offline.
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Audio description track is always set as the default audio track

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