Video: Integrating CMAF Into A VOD Workflow

CMAF is often seen as the best hope for streaming to match the latency of broadcast. Fully standards based, many see this as the best route over Apple’s LL-HLS. Another benefit of it over LL-HLS is that it’s already a completed standard with growing support.

This talk from Tomas Bacik starts by explaining CMAF to us. Standing for the Common Media Application Format, it’s based on the standardised ISOBMFF container format and whilst CMAF isn’t by default low-latency, it is flexible enough to deliver just that. However, as Tomas from CDN77 points out, there are other major benefits in terms of its use of the Common Encryption format, reduces storage fees and more.

MPEG DASH is a commonly found streaming format based on ISO BMFF. It has always had the benefit of supporting other codecs such as HEVC and AV1 over HLS which is an AVC-only specification. CMAF is an extension of MPEG DASH which goes one step further in that it can deal with both HLS-style manifest files (.hls) as well as MPEG DASH format (.mpd) inheriting, of course, the multi-codec ability of DASH itself.

Next is central theme of the talk, looking at VoD workflows showing how CMAF fits in and, indeed, changes workflows for the better. CMAF directly impacts packaging, storage and CDN which is where we focus now. Given that some devices can play HLS and some can play DASH, if you try to serve both, you will double your requirements of packaging, storage etc. Dynamic packaging allows for immediately repackaging your chunks into either HLS or DASH as needed. Whilst this reduces the storage requirements, it increases processing and also increases the time to first byte. As you might expect, using CMAF throughout, Tomas explains in this talk, allows you to package once and store once which solves these problems.

Tomas continues by explaining the DRM abilities of CMAF including AES-CBC and finishes by taking questions from the audience.

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Speakers

Tomas Bacik Tomas Bacik
VP of Product Development, Streamflow by CDN77
CDN77

Video: Deploying CMAF In 2019

It’s all very good saying “let’s implement CMAF”, but what’s implemented so far and what can you expect in the real world, away from hype and promises? RealEyes took the podium at the Video Engineering Summit to explain.

CMAF represents an evolution of the tried and tested technologies HLS and DASH. With massive scalability and built upon the well-worn tenants of HTTP, Netflix and a whole industry was born and is thriving on these still-evolving technologies. CMAF stands for the Common Media Application Format because it was created to allow both HLS and DASH to be implemented in one common standard. But the push to reduce latency further and further has resulted in CMAF being better known for it’s low-latency form which can be used to deliver streams with five to ten times lower latencies.

John Gainfort tackles explaining CMAF and highlights all the non-latency-related features before then tackling its low-latency form. We look at what it is (a manfest) and where it came from (ISO BMFF before diving in to the current possibilities and the ‘to do list’ of DRM.

Before the Q&A, John then moves on to how CMAF is implemented to deliver low-latency stream: what to expect in terms of latency and the future items which, when achieved, will deliver the full low-latency experience.

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Speaker

John Gainfort John Gainfort.
Development Manager,
RealEyes

Video: Making Live Streaming More ‘Live’ with LL-CMAF

Squeezing streaming latency down to just a few seconds is possible with CMAF. Bitmovin guides us through what’s possible now and what’s yet to come.

CMAF represents an evolution of the tried and tested technologies HLS and DASH. With massive scalability and built upon the well-worn tenants of HTTP, Netflix and a whole industry was born and is thriving on these still-evolving technologies. But the push to reduce latency further and further has resulted in CMAF which can be used to deliver streams with five to ten times lower latencies.

Paul MacDougall is a Solutions Architect with Bitmovin so is well placed to explain the application of CMAF. Starting with a look at what we mean by low latency, he shows that it’s still quite possible to find HLS latencies of up to a minute but more common latencies now are closer to 30 seconds. But 5 seconds is the golden latency which matches many broadcast mechanisms including digital terrestrial, so it’s no surprise that this is where low latency CMAF is aimed.

CMAF itself is simply a format which unites HLS and DASH under one standard. It doesn’t, in and of itself, mean your stream will be low latency. In fact, CMAF was born out of MPEG’s MP4 standard – officially called ISO BMFF . But you can use CMAF in a low-latency mode which is what this talk focusses on.

Paul looks at what makes up the latency of a typical feed discussing encoding times, playback latency and the other key places. With this groundwork laid, it’s time to look at the way CMAF is chunked and formatted showing that the smaller chunk sizes allow the encoder and player to be more flexible reducing several types of latency down to only a few seconds.

In order to take full advantage of CMAF, the play needs to understand CMAF and Paul explains these adaptations before moving on to the limitations and challenges of using CMAF today. One important change, for instance, is that chunked streaming players (i.e. HLS) have always timed the download of each chunk to get a feel for whether bandwidth was plentiful (download was quicker than time taken to play the chunk) or bandwidth was constrained (the chunk arrived slower than real-time). Based on this, the player could choose to increase or decrease the bandwidth of the stream it was accessing which, in HLS, means requesting a chunk from a different playlist. Due to the improvements in downloading smaller chunks and using real-time transfer techniques such as HTTP/1.1 Chunked Transfer the chunks are all arriving at the download speed. This makes it very hard to make ABR work for LL-CMAF, though there are approaches being tested and trialed not mentioned in the talk.

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Speakers

Paul MacDougall Paul MacDougall
Solutions Architect,
Bitmovin

Webinar: Low-Latency CMAF vs. WebRTC

CMAF brings low latency streams of less than 4 seconds into the realms of possibility, WebRTC pushes that below a second – but which is the right technology for you?

Date: June 12th 2019 Time: 11am PST / 2pm EST / 19:00 BST

CMAF represents an evolution of the tried and tested technologies HLS and DASH. With massive scalability and built upon the well-worn tenants of HTTP, Netflix and a whole industry was born and is thriving on these still-evolving technologies. The push to reduce latency further and further has resulted in CMAF which can be used to deliver streams with five to ten times lower latencies.

WebRTC is a Google-backed streaming protocol with the traditional meaning of streaming; it pushes a stream to you a opposed to the HLS-style methods of making small files available for download and reassembly into a stream. One benefit of this is extremely low bitrates of 1 second or less. Used widely by Google Hangouts and Facebook messenger, WebRTC is increasingly an option for more broadcast-style streaming services from live sports & music to gaming and gambling.

Both have advantages and draw-backs so Wowza’s Barry Owen and Anne Balistreri are here to help navigate the ins and outs of both technologies plus answer your questions.

Register now!

Speakers

Barry Owen Barry Owen
VP, Professional Services,
Wowza
Anne Balistreri Anne Balistreri
Product Marketing Manager,
Wowza