CMAF LL-HLS Stream issue

[Tom_Ryan]

When I enable LL-HLS in my live application, I am experiencing an issue with audio being delivered in the mpeg-dash stream. The audio is delivered fine via playlist.m3u8 and playlist_sfts.m3u8.

Is it not possible to use LL-HLS in a live application along with mpeg-dash?

[Rose_Power-Wowza_Com]

The partial segments known as fmp4 (fragmented mp4) that are created by the CMAF packetizer allows you to use those segments for either LL-HLS or MPEG-DASH streams.

You do have to enable the cmafstreamingpacketizer and not just enable the LL-HLS. Did you do that @Tom Ryan?

Here a couple of docs on how to do that:

How to enable cmafstreamingpacketizer:

https://www.wowza.com/docs/stream-using-cmaf-with-wowza-streaming-engine

How to configure once it is enabled:

https://www.wowza.com/docs/configure-cmaf-packetization-in-wowza-streaming-engine

KEEP IN MIND!

Enabling mepgdashstreamingpacketizer and cmafstreamingpacketizer is valid but redundant, as both create fMP4 segments. If both are defined in Application.xml, Wowza Streaming Engine ignores mpegdashstreamingpacketizer and produces one set of fMP4 segments using cmafstreamingpacketizer.

[Tom_Ryan]

Yes, I followed the directions. I do have both set (but as the directions note, it doesn’t matter). The only impact is that audio is not sent in the mpeg dash stream once I add the property

cmafLLEnableLowLatency

[Rose_Power-Wowza_Com]

Let me know after you check the above if you are still having issues with the audio being delivered for DASH and provide more details on the manifest. Thanks.

[Tom_Ryan]

Sorry, my other response is held in moderation. I followed the directions as noted in those documents already.

[Rose_Power-Wowza_Com]

Ok give me a minute to discuss with tech support.

[Rose_Power-Wowza_Com]

Hi @Tom Ryan, so we are currently updating the docs to make this more clear and I apologize for any confusion this caused you.

A. CMAF HLS/DASH

You will need to set will up one application for CMAF HLS/DASH here:

https://www.wowza.com/docs/stream-using-cmaf-with-wowza-streaming-engine

B. You’ll need to setup a 2nd application for LL-HLS here:

https://www.wowza.com/docs/deliver-apple-low-latency-hls-live-streams-using-wowza-streaming-engine

It appears you cannot configure both from one application and again we are updating docs to make that clear. Can you try that and let us know if your audio works now? Our engineer tested it and had success following the first doc I posted for DASH, but we are going to watch for your reply to see what your results are.

Thanks so much.

[Tom_Ryan]

Rose, thank you for getting back to me. I figured that was the case (hence my original question!). I don’t need to test it as I know it works as you state, I just wasn’t clear if I needed to have two (not that big of a deal)

Thanks for confirming!

p.s. I will need to play with getting the content to be available in both applications.

[Rose_Power-Wowza_Com]

You’re welcome and thanks for giving us the opportunity to clarify that in our docs. Another great example of how valuable community feedback is to us!