Multiple Video Tracks for HLS/DASH live streaming

Wowza Streaming Engine
1

Hi,

According to the article: https://www.wowza.com/docs/how-to-use-alternative-audio-or-video-tracks-with-apple-hls-streams

It says “For everything to be synchronized, the alternative tracks must be timecode-aligned. This means that they must come from the same encoder or from separate encoders that produce aligned streams.”

I have two IP encoders sharing the same clock by using a local NTP server, but the timing for key frames is not the same. Will it still be synched for the alternative tracks? If not, what has to be done?

Besides, do alternate video tracks also apply to live DASH? In HLS we can use ‘videoindex=’ parameter to get a track, so I wonder if this also works for live DASH.

Thanks!

2

Hi,

You must ensure that the individual sources are keyframe aligned for ABR to work properly.

I would expect the videoindex query parameter should work with a source stream. Do you have an example stream with that not working with DASH and we can take a closer look. It may be better in this case to open a support ticket

Paul