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As you all know, Flash is likely to be entirely replaced by HTML5 which we cannot use RTMP anymore. For that reason, I am looking into MPEG-DASH but it seems like it has a very high latency? I tried MPEG-DASH with wowza live streaming engine and I got a 50-second latency which is utterly not acceptable. I need latency < 3 seconds.

As this article states: https://blog.red5pro.com/webrtc-one-to-many-broadcasting-why-latency-is-important-what-the-future-holds/

MPEG-DASH has a High latency, but I need some theoretical truths which I can use to convince my colleagues that we cannot use MPEG-DASH? Any MPEG-DASH experts? or any good essays that explain how MPEG-DASH works under the hood?

Thanks

Thenewstockton
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    Minimum is whatever your segment duration/GOP size is. Then add in whatever the transcoding/cdn/etc adds – szatmary Sep 08 '16 at 17:03
  • Time and time again, I see folks outright demanding low latency but never explaining why. "... which is utterly not acceptable. I need latency <3 seconds." **Why?** Firstly, are you absolutely sure of this? If I watch the Super Bowl on DirecTV (arguably one of the most watched live events of the year) I'm 15 seconds behind, and nobody notices. And, if you do need this, do you actually need it for all clients? (See my post here for a similar question: http://stackoverflow.com/a/37475943/362536) And, how many clients do you need to stream to? This is important information. – Brad Sep 20 '16 at 03:19
  • You need to be aware (if you aren't already) that there are some important tradeoffs between latency, quality, scalability, and costs. Are you prepared to damage your video quality to push your latency down by a few seconds? Are willing to hire a small team to work on your technical issues from your custom rig for scaling low latency video? If you answer yes to those and can provide more details as to what scale you're looking at, better answers to your problem can be given. – Brad Sep 20 '16 at 03:23

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The theoretical lower limit for latency using MPEG-DASH with ISOBMFF packaging is the frame (excluding encoding time, CDN ...). It can be achieved by storing a single frame in a single ISOBMFF movie fragment, and by delivering it as an HTTP chunk. Using this approach, the latency is the movie fragment duration. This has no consequence on the segment duration. You can still have 1, 2 or 10 seconds segments if you want. This was demonstrated in local area network. You need to add the encoding/decoding times and the download delay itself (propagation and caching). More information in this publication. You can also test some real streams here using GPAC tools.

cconcolato
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