Video: What Is the Future of CMAF?
Learn more about CMAF at Streaming Media's next event.
Watch John Gainfort's complete presentation, VES 102. Deploying CMAF in 2019, in the Streaming Media Conference Video Portal.
Read the complete transcript of this clip:
John Gainfort: Today, how the latency is derived, is we have our content coming in and we're going to generate a content and, for a six-second segment, we had to encode, generate this entire segment over six seconds. We then need to upload that segment to our origin. If that's successful, we then update our manifests. If those are successful, then we're going to propagate that to our CDN or owe it to our edges, deliver that to our client. And, by default, we're going to try to buffer three seconds of segments--that is an Apple standard--before we even begin playback. So, at six seconds, we're looking at a minimum of 18 seconds of latency just before a user could play this back.
Now, to combat that, we can do two things. We can do chunked encoding or chunked transfer encoding. So chunked encoding is how it's going to be made. Chunked transferring is how it's delivered. So, how the encoder breaks down and saves the data is chunked encoding and then chunked transfer, how the data's sent and made available without knowing a final size.
Using HTTP 1.1 we can stream our content now, through our entire system. So, we encode our CMAF segment using chunked encoded content or CMAF segment content is chunked encoded. We update our manifest before it's fully created. We can push this up through to our origin and through our CDN using HTTP 1.1. We can distribute that now through the rest of our CDN tiers using HTTP 1.1 and then the player can now request their content using a fetch first in XHR API to then read and download those segments as they come in.
It's still going to take the same six seconds to download this segment size, but the big benefit is that somebody's going to be behind your live points. So, in let's say 18 seconds, you're going to see a massive decrease in how long it takes for your client to download those same segments. So, chunked encoding transfer is based on HTTP 1.1.
This technology has been around for 21 years, so your CDNs today will be able to support this, for the most part. You're going be able to utilize their same existing caching systems to achieve your scale and this is proven technology that already is out there supporting millions of viewers.
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