Wowza Community

Low latency stream with TS chunks instead of CMAF

Hi,

I have followed this article https://www.wowza.com/docs/deliver-apple-low-latency-hls-live-streams-using-wowza-streaming-engine to play an LLHLS stream,

when i try to open this url: [STREAMLOCK-HOST]/live/[STREAM-NAME]/playlist_sfts.m3u8 it defaults to normal latency stream and not apple low latency stream, whereas when I use this url for [STREAMLOCK-HOST]/live/[STREAM-NAME]/playlist_sfm4s.m3u8 which give cmf chunks and not ts, i streams in apply low latency, what is causing this? How do i stream low latency with TS files?

I’ve tested this on HLS JS demo page https://hls-js-0bd03ae0-14e6-4a69-a198-a0fa2cc343ea.netlify.app/demo/

Is Low latency streaming possible with .ts container format with wowza?

The LL-HLS spec uses fmp4 (fragmented mp4) and MPEG uses the ts files. The Streaming Engine CMAF packetizer creates both types of chunks but you need you create a different application for each one.

The packetizer creates chunks that are used as the video and audio partial segments needed for LL-HLS. The LL-HLS streams use the fMP4 container format and are delivered to players over HTTP/2.


Did you check this already?

To deliver LL-HLS streams from Wowza Streaming Engine you have to manually enable low latency CMAF packetization for live streaming, in the application, by editing the application’s configuration in XML.

This must also be done:

  • In order to generate an LL-HLS streams you must first get a SSL/TLS certificate to secure your port and configure the port for HTTPS playback. LL-HLS playback does not work without an SSL/TLS secured port. For information on how to do this, refer to Get SSL/TLS certificates from the Wowza Streaming Engine StreamLock service.

  • If you’re trying to use the CMAF packetizer to deliver LL-HLS and HLS or MPEG-DASH streams, you must use two separate live applications: one configured specifically for LL-HLS and another for CMAF-packetized HLS and MPEG-DASH.


If you are still having issues, makes sure you are testing on a LL-HLS device:
LL-HLS streams can be played in native apps on devices running iOS 13. In order to enable low-latency playback, a native app must carry the com.apple.developer.coremedia.hls.low-latency entitlement.


The fastest way for us to debug is to review your files and configuration in order to quickly identify the issue. We are unable to debug in the forums without full access to your files and logs. A ticket will be required:

https://www.wowza.com/support/open-ticket