Video: Deep Neural Networks for Video Coding

Artificial Intelligence, Machine Learning and related technologies aren’t going to go away…the real question is where they are best put to use. Here, Dan Grois from Comcast shows their transformative effect on video.

Some of us can have a passable attempt at explaining what neural networks, but to start to understand how this technology works understanding how our neural networks work is important and this is where Dan starts his talk. By walking us through the workings of our own bodies, he explains how we can get computers to mimic parts of this process. This all starts by creating a single neuron but Dan explains multi-layer perception by networking many together.

As we see examples of what these networks are able to do, piece by piece, we start to see how these can be applied to video. These techniques can be applied to many parts of the HEVC encoding process. For instance, extrapolating multiple reference frames, generating interpolation filters, predicting variations etc. Doing this we can achieve a 10% encoding improvements. Indeed, a Deep Neural Network (DNN) can totally replace the DCT (Discrete Cosine Transform) widely used in MPEG and beyond. Upsampling and downsampling can also be significantly improved – something that has already been successfully demonstrated in the market.

Dan isn’t shy of tackling the reason we haven’t seen the above gains widely in use; those of memory requirements and high computational costs. But this work is foundational in ensuring that these issues are overcome at the earliest opportunity and in optimising the approach to implementing them to the best extent possible to day.

The last part of the talk is an interesting look at the logical conclusion of this technology.

Watch now!

Speaker

Dan Grois Dan Grois
Principal Researcher
Comcast

Video: Bandwidth Prediction in Low-Latency Chunked Streaming

How can we overcome one of the last, big, problems in making CMAF generally available: making ABR work properly.

ABR, Adaptive Bitrate is a technique which allows a video player to choose what bitrate video to download from a menu of several options. Typically, the highest bitrate will have the highest quality and/or resolution, with the smallest files being low resolution.

The reason a player needs to have the flexibility to choose the bitrate of the video is mainly due to changing network conditions. If someone else on your network starts watching some video, this may mean you can no longer download video quick enough to keep watching in full quality HD and you may need to switch down. If they stop, then you want your player to switch up again to make the most of the bitrate available.

Traditionally this is done fairly simply by measuring how long each chunk of the video takes to download. Simply put, if you download a file, it will come to you as quickly as it can. So measuring how long each video chunk takes to get to you gives you an idea of how much bandwidth is available; if it arrives very slowly, you know you are close to running out of bandwidth. But in low-latency streaming, your are receiving video as quickly as it is produced so it’s very hard to see any difference in download times and this breaks the ABR estimation.

Making ABR work for low-latency is the topic covered by Ali in this talk at Mile High Video 2019 where he presents some of the findings from his recently published paper which he co-authored with, among others, Bitmovin’s Christian Timmerer and which won the DASH-IF Excellence in DASH award.

He starts by explaining how players currently behave with low-latency ABR showing how they miss out on changing to higher/lower renditions. Then he looks at the differences on the server and for the player between non-low-latency and low-latency streams. This lays the foundation to discuss ACTE – ABR for Chunked Transfer Encoding.

ACTE is a method of analysing bandwidth with the assumption that some chunks will be delivered as fast as the network allows and some won’t be. The trick is detecting which chunks actually show the network speed and Ali explains how this is done and shows the results of their evaluation.

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Speaker

Ali C. Begen Ali C. Begen
Technical Consultant and
Computer Science Professor

Video: What is Happening with IMF?

IMF is an interchange format designed for post-production/studios versioning requirements. It reduces storage required for multi-version projects but also provides for a standard way of exchanging metadata between companies.

Annie Chang covers the history briefly of IMF showing what it was aiming to achieve. IMF has been standardised through SMPTE as ST 2067 and has gained traction within the industry hence the continued interest in extending the standard. As with all modern standards, this has been created to be extensible, so Annie gives details on what is being added to it and where these endeavours have got to.
 

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Speaker

Annie Chang Annie Chang
VP, Creative Technologies,
Universal Pictures

Video: Live Streaming: Dead Air is Not an Option

Stuart Kurkowski Tells us about SCTE 224 which allows control of who watches live streams, where and on which devices. This technology is key to implementing contractual boundaries for streamed material but also facilitated

The talk covers:
• What restrictions are found in the market today
• What SCTE 224 is
• What data is in a SCTE 224 message
• How it provides the same control satellite operators have for IP streaming
• Ensuring The EPG on a device shows what will be available and not what will be blocked or swapped
• Extending this to Ad breaks

Watch now!

Speaker

Stuart Kurkowski Stuart Kurkowski
Distinguished Engineer,
Comcast Technology Solutions