Video: The ROI of Deploying Multiple Codecs

Adding a new codec to your streaming service is a big decision. It seems inevitable that H.264 will be around for a long time and that new codecs won’t replace it, but just take their share of the market. In the short term, this means your streaming service may also need to deliver H.264 and your new codec which will add complexity and increase CDN storage requirements. What are the steps to justifying a move to a new codec and what’s the state of play today?

In this Streaming Media panel, Jan Ozer is joined by Facebook’s Colleen Henry, Amnon Cohen-Tidhar from Cloudinary and Anush Moorthy from Netflix talk about their experiences with new codecs and their approach to new Codecs. Anush starts by outlining the need to consider decoder support as a major step to rolling out a new codec. The topic of decoder support came up several times during this panel in discussing the merits of hardware versus software decoding. Colleen points out that running VP9 and VVC is possible, but some members of the panel see a benefit in deploying hardware – sometimes deploying on devices like smart TVs, hardware decoding is a must. When it comes to supporting third party devices, we hear that logging is vitally important since when you can’t get your hands on a device to test with, this is all you have to help improve the experience. It’s best, in Facebook’s view, to work closely with vendors to get the most out of their implementations. Amnon adds that his company is working hard to push forward improved reporting from browsers so they can better indicate their capabilities for decoding.

 

 

Colleen talks about the importance of codec switching to enhance performance at the bottom end of the ABR ladder with codecs like AV1 with H264 at the higher end. This is a good compromise between the computation needed for AV1 and giving the best quality at very low bitrates. But Anush points out that storage will increase when you start using two codecs, particularly in the CDN so this needs to be considered as part of the consideration of onboarding new codecs. Dropping AV1 support at higher bitrates is an acknowledgement that we also need to consider the cost of encoding in terms of computation.

The panel briefly discusses the newer codecs such as MPEG VVC and MPEG LCEVC. Colleen sees promise in VVC in as much as it can be decoded in software today. She also says good things about LCEVC suggesting we call it an enhancement codec due to the way it works. To find out more about these, check out this SMPTE talk. Both of these can be deployed as software decoders which allow for a way to get started while hardware establishes itself in the ecosystem.

Colleen discusses the importance of understanding your assets. If you have live video, your approach is very different to on-demand. If you are lucky enough to have an asset that is getting millions upon millions of views, you’ll want to compress every bit out of that, but for live, there’s a limit to what you can achieve. Also, you need to understand how your long-tail archive is going to be accessed to decide how much effort your business wants to put into compressing the assets further.

The video comes to a close by discussing the Alliance of Open Media’s approach to AV1 encoders and decoders, discussing the hard work optimising the libAV1 research encoder and the other implementations which are ready for production. Colleen points out the benefit of webassembly which allows a full decoder to be pushed into the browser and the discussion ends talking about codec support for HDR delivery technologies such as HDR10+.

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Speakers

Colleen Henry Colleen Henry
Cobra Commander of Facebook Video Special Forces.
Anush Moorthy Anush Moorthy
Manager, Video & Imagine Encoding
Netflix
Amnon Cohen-Tidhar Amnon Cohen-Tidhar
Senior Director or Video Architecture,
Cloudinary
Jan Ozer Moderator: Jan Ozer
Principal, Stremaing Learning Center
Contributing Editor, Streaming Media

Video: Solving the 8K distribution Challenge

With the Tokyo Olympics less than 2 weeks away, 8K is back in focus. NHK have famously been key innovators and promoters of 8K for many years, have launched an 8K channel on satellite and will be broadcasting the games in 8K. That’s all very well, but is 8K a viable broadcast format for other public and commercial broadcasters? One problem for 8K is how to get it to people. Whilst there are plenty of bandwidth problems to contend with during production, all of that will be for nought if we can’t get it to the customer.

This panel, run by the 8K Association in conjunction with SMPTE, looks to new codecs to help reduce the burden on connectivity whether RF or networks. The feeling is that HEVC just can’t deliver practical bandwidths, so what are the options? The video starts with Bill Mandel from Samsung introducing the topics of HDR display using HDR10+, streaming with CMAF and bandwidth. Bill discusses future connectivity improvements which should come into play and then looks at codec options.

 

 

Bill and Stephan Wenger give their view on the codecs which were explained in detail in this SMPTE deep dive video so do take a look at the article for more context. AV1 is the first candidate for 8K distribution that many think of since it is known to have better compression than HEVC and is even seeing some hardware support in TVs and is being trialled by YouTube. However, the trailer is 50Mbps and therefore not suitable for many connections. Looking at better performance, MPEG’s EVC is a potential candidate which offers continued improvement over AV1 and a better licensing model than HEVC. Stephan’s view on codecs is that users really don’t care what the codec is, they just need the service to work. He points towards VVC, the direct successor to HEVC, as a way forward for 8K since it delivers 40 to 50% bandwidth reduction opening up the possibility of a 25Mbps video channel. Noa published MPEG standard, the market awaits patent information and vendor implementations.

Stephan talks about MPEG’s LCEVC standard which has similarities to Samsung’s Scalenet which Bill introduced. The idea is to encode at a lower resolution and use upscaling to get the desired resolution using AI/machine learning to make the scaling look good and, certainly in the case of LCEVC, a low-bandwidth stream of enhancement data which adds in key parts of video, such as edges, which would otherwise be lost. Stephan says that he awaits implementations in the market to see how well this works. Certainly, taking into account LCEVC’s ability to produce compression using less computation, it may be an important way to bring 8K to some devices and STBs.

The discussion is rounded off by Mickael Raulet, CTO of ATEME who talks us through an end-to-end test broadcast done using VVC. This was delivered by satellite to set top boxes and over streaming with a UHD channel at 15Mbps. His take-away from the experience is that VVC is a viable option for broadcasters and 8K and may be possible with using EVC’s main profile. The video finishes with a Q&A covering:

  • Codecs for live video
  • The pros and cons of scaling in codecs
  • Codec licensing
  • Multiple generational encoding degeneration

     
     

    Watch now!
    Speakers

    Bill Mandel Bill Mandel
    VP, Industry Relations,
    Samsung Research America
    Mickaël Raulet Mickaël Raulet
    CTO,
    ATEME
    Chris Chinnock
    Executive Director,
    8K Association
    Stephan Wenger Stephan Wenger
    Senior Director, IP & Standards,
    Tencent
  • Video: Build The New Generation Of Real Time Streaming Solutions With WebRTC

    WebRTC continues to live two lives; one of massive daily use in video conferencing in apps from Google, Facebook as well as many others, and one as a side-lined streaming protocol in hte broadcast and streaming industry. WebRTC is now an IETF/W3C standard, is a decade old and is seeing continued work and innovation from Google, other large companies and smaller specialists pushing it forward.

    In this extended Streaming Media Connect video with Millicast’s Ryan Jespersen, we explore where WebRTC is up to now, how it can replace RTMP, how real-time AV1 not only shows the innovation within the technology but also enables several use cases and upcoming technologies such as end-to-end encryption for streaming workflows. The video is in sections: product demos, technology discussion and overviews of use cases.

    A clear first question is why bother with WebRTC at all. Ryan’s quick to point out that WebRTC is in daily use not only in many of the big video call apps but also in Clubhouse, the high-scale WebRTC-based interactive audio platform. He also establishes that it’s commonly in use on CDNs such as Limelight and Millicast to deliver ultra-low-latency streams to end-users for auctions, gambling and interactive streams, but also as part of broadcast workflows. NFL, for instance, used WebRTC for low-latency monitoring of 122 cameras for the Super Bowl. As far as end-users are concerned, Ryan sees the ‘interactivity’ market as a way, as yet untapped, to release value in many verticals and will be the fastest-growing sector of the streaming industry over the next few years.

     

     

    Looking back at Flash, Ryan explains that we came from a point where we had a low-latency protocol in the name of RTMP. Its latency was in the realms of 1 to 3 seconds, it had end-to-end security, encoder control and interactivity. RTMP was displaced due to three main factors, security concerns, rejection of the proprietary nature of the protocol and the move to HLS which provided improved scalability and was enthusiastically adopted by CDNs.

    WebRTC, Ryan contends, learns from the mistakes of RTMP. WebRTC has ways to recover lost packets, is content agnostic, has a solution for NAT traversal, is non-proprietary and has no plugins. These latter two points address many of the security concerns of RTMP. Now a standard, the W3C has documented many upcoming use cases for this free, Open Source, technology.

    Why, then, do we not see WebRTC much more prevalent in video streaming such as Netflix or Peacock? This is a question that Russell Trafford-Jones discussed in this IBC panel with nanocosmos, M2A and VisualOn. One view from that panel is that sub-second is lower than needed for some services. For instance, a public broadcaster may not wish to deliver online faster than it does over the air. Also, there’s a quality issue to contend with. One strength of WebRTC is that it prioritises latency over quality, always. This is great for face-to-face communication, but tier-1 broadcasters want people to see video in the same quality that left their encoders and if that means waiting for packets to be recovered instead of showing an impaired signal, that’s what they will do. As ever, therefore, this is a business decision that has to pay careful attention to the needs of the viewers, the quality aspirations of the viewers and broadcaster/provider as well as the technical pros and cons of each approach.

    Ryan tlks about Real-time AV1 in WebRTC covered also in this talk

    Moving on to AV1, Ryan explains that this royalty-free codec has been sped up significantly since the early days when it required thousands of CPUs for real-time encoding. Using AV1 is a boon for WebRTC for two reasons: screen content and scalable video coding. Screen Content Coding is a set of techniques to adapt encoding specifically for screen content meaning computer graphics whether that be in games or just sending a computer desktop. With straighter lines and the possibility for many parts of the screen to be identical or close to identical to other parts, it’s possible to get much better encoding for screen content if you can detect it and optimise for it.

    Ryan moves on to AV1’s use in shoring up security. Although a codec and not a security measure in and of itself, AV1’s ability to send multiple resolutions in one stream is a big deal for securing communications. Scalable video coding, SVC, is not a new technology, but AV1 is one of the first mainstream, modern codecs which has it by default. This enables an encoder to encode to, say, sub-SD, SD and HD resolution and send these all at once in one stream. These are not simply 3 encodes squeezed down the same pipe, but they encode that build on top of each other. The sub-HD provides a foundation on which the SD feed provides enhancement information. You need both the sub-SD and SD layer to get SD. Adding on the HD layer to those two gives you that full-resolution HD. By only delivering the extra information needed for HD rather than all the underlying data again, a lot of bitrate can be saved. Importantly, by generating all the encoding at the source, you can encrypt at the source for an end-to-end encrypted workflow and also deliver multiple bitrates. Ryan explains that the move to ABR streaming, whether HLS, DASH or otherwise breaks the end-to-end security model as the need to transcode the media necessitates being able to view it. Using AV1’s SVC is one way around the need for mid-workflow transcoding.

    One aspect is missing, though, for modern streaming workflows. If you don’t want to do peer-to-peer networking, some form of traffic manipulation will be needed in your CDN and/or delivery infrastructure. This is why Ryan says that Millicast has proposed that ‘secure frames’ are added to the WebRTC spec. Whilst this talk doesn’t detail their functionality they add a way of encrypting data twice such that the media can be encrypted for end-to-end workflows, but also each hop can be separately encrypted. This provides just enough access to the metadata of the stream for traffic manipulation, but without allowing access to the underlying media.

    As the video comes to end, Ryan gives us a glimpse into one other upcoming technology that may be added to WebRTC called WHIP. The RFC explains the intention of WHIP:

    The WebRTC-HTTP ingest protocol (WHIP) uses an HTTP POST request to
    perform a single shot SDP offer/answer so an ICE/DTLS session can be
    established between the encoder/media producer and the broadcasting
    ingestion endpoint.
    
    Once the ICE/DTLS session is set up, the media will flow
    unidirectionally from the encoder/media producer broadcasting
    ingestion endpoint. In order to reduce complexity, no SDP
    renegotiation is supported, so no tracks or streams can be added or
    removed once the initial SDP O/A over HTTP is completed.

    Ryan closes his video with a demonstration of the Millicast platform and looks at how other use cases might be architected such as watch parties.

    Watch now!
    Download the slide deck

    Speaker

    Ryan Jespersen Ryan Jespersen
    Head of Sales and Marketing
    Millicast

    Video: AV1 and ARM

    AV1’s no longer the slow codec it was when it was released. Real-time encodes and decodes are now practical with open-source software implementations called rav1e for encoding and dav1d for decoding. We’ve also seen in previous talks the SVT-AV1 provides real-time encoding and WebRTC now has a real-time version with the AV1 codec.

    In this talk, rav1e contributor Vibhoothi explains more about these projects and how the ARM chipset helps speed up encoding. The Dav1d started project started in 2018 with the intention of being a fast, cross-platform AV1 encoder with a small binary which Vibhoothi says is exactly what we have in 2021. Dav1d is the complementary decoder project. AV1 decoding is found in many places now including in Android Q, in Microsoft’s media extension for it, VLC supports AV1 on linux and macOS thanks to dav1d, AV1 is supported in all major browsers, on NVIDIA and AMD GPUs plus Intel Tiger Lake CPUs. Netflix even use dav1d to stream AV1 onto some mobile devices. Overall, then, we see that AV1 has ‘arrived’ in the sense that it’s in common and increasing use.

    The ARM CPU architecture underpins nearly all smartphones and most tablets so ARM is found in a vast number of devices. It’s only relatively recently that ARM has made it into mainstream servers. One big milestone has been the release of Neoverse which is an ARM chip for infrastructure. AWS now offer ARM instances that have a 40% higher performance but a 20% reduced cost. These have been snapped up by Netflix but also by a plethora of non-media companies. Recently Apple has made waves with their introduction of the M1 ARM-based chip for desktops which has benchmarks far in excess of the previous x86 offering which shows that the future for ARM-based implementations of the rav1e encoder and dav1d decoder are bright.

    Vibhoothi outlines how dav1d works better on ARM then x86 with improved threading support including hand-written asm optimisations and support for 10-bit assembly. rav1e has wide support in VLC, GStreamer, FFmpeg, libavif and others.

    The talk finishes with a range of benchmarks showing how better-than-real-time encoding and decoding is possible and how the number of threads relates to the throughput. Vibhoothi’s final thoughts focus on what’s still missing in the ARM implementations.

    Watch now!
    Speaker

    Vibhoothi Vibhoothi
    Developer, VideoLAN
    Research Assistant, Trinity College Dublin,
    Codec Development, rav1e, Mozilla