Video: Super Resolution: What’s the buzz and why does it matter?

“Enhance!” the captain shouts as the blurry image on the main screen becomes sharp and crisp again. This was sci-fi – and this still is sci-fi – but super-resolution techniques are showing that it’s really not that far-fetched. Able to increase the sharpness of video, machine learning can enable upscaling from HD to UHD as well as increasing the frame-rate.

Bitmovin’s Adithyan Ilangovan is here to explain the success they’ve seen with super-resolution and though he concentrates on upscaling, this is just as relevant to improving downscaling. Here are our previous articles covering super resolution.

Adithyan outlines two main enablers of super resolution, allowing it to displace the traditional methods such as bicubic and Lanczos. Enabler one is the advent of machine learning which now has a good foundation of libraries and documentation for coders allowing it to be fairly accessible to a wide audience. Furthermore, the proliferation of GPUs and, particularly for mobile devices, neural engines is a big help. Using the GPUs inside CPUs or in desktop PCI slots allows the analysis to be done locally without transferring great amounts of video to the cloud solely for the purpose of processing or identification. Furthermore, if your workflow is in the cloud, it’s now easy to rent GPUS and FPGAs to handle such workloads.

Using machine learning doesn’t only allow for better upscaling on a frame-by-frame basis, but we are also able to allow it to form a view of the whole file, or at least whole scene. With abetter understanding of the type of video it’s analysing (cartoon, sports, computer screen etc.) it can tune the upscaling algorithm to deal with this optimally.

Anime has seen a lot of tuning for super resolution. Due to Anime’s long history, there are a lot of old cartoons which are both noisy and low resolution which are still enjoyed now but would benefit from more resolution to match the screens we now routinely used.

Adithyan finishes by asking how we should best take advantage of super resolution. Codecs such as LCEVC use it directly within the codec itself, but for systems which have pre and post-processing before the encoder, Adithyan suggests it’s viable to consider reducing the bitrate to reduce the CDN costs knowing the using super-resolution on the decoder, the video quality can actually be maintained.

The video ends with a Q&A.

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Speaker

Adithyan Ilangovan Adithyan Ilangovan
Encoding Engineer,
Bitmovin

Video: State of Compression: Versatile Video Coding – H.266/VVC

An evolution from HEVC, VVC is a codec that not only delivers the traditional 50% bit rate reduction over its predecessor but also has specific optimisations for screen content (e.g. computer gaming) and 360-degree video.

Christian Feldmann from Bitmovin explains how VCC manages to deliver this bitrate reduction. Whilst VVC makes no claims to be a totally new codec, Christian explains that the fundamental way the codec works, at a basic level, is the same as all block-based codecs including MPEG 2 and AV1. The bitrate savings come from incremental improvements in technique or embracing a higher computation load to perform one function more thoroughly.

Block partitioning is one good example. Whilst AVC macroblocks are all 16×16 pixels in size, VVC allows 128×128 blocks. For larger areas of ‘solid’ colour, this allows for more efficiency. But the main advance comes in the fact you can sub-divide each of these blocks into different sized rectangles. Whilst sub-dividing has always been possible back to AVC, we have more possible shapes available now allowing the divisions to be created in closer alignment with the video.

Tiles and slices are a way of organising the macroblocks, allowing them to be treated together as a group. This is grouping isn’t taken lightly; each group can be decoded separately. This allows the video to be split into sub-videos. This can be used for multiviewer-style applications or, for instance, to allow multiple 4k decoders to decode a 16k. This could be one of those features which sees lots of innovative use…or, if it’s too complicated/restricted, will see no mainstream take-up.

Christian outlines other techniques such as intra-prediction where macroblocks are predicted from already-decoded macroblocks. Any time a codec can predict a value, this tends to reduce bitrate. Not because it necessarily gets it right, but because it then only needs an error-correction, typically a smaller number, to give it the correct value. Similarly, prediction is also possible now between the Y, U and V channels.

Finishing off, Christian hits geometric partitioning, similar to AV1, which allows diagonal splitting of macroblocks with each section having separate motion vectors. He also explains affine motion prediction, allowing blocks to scale, rotate, change aspect ration and shear. Finally Christian discusses the performance possible from the codec.

To find out more about VVC, including the content-based tuning such as for screen graphics, which is partly where the ‘versatile’ in VVC’s name comes from, listen to this talk, from 19 minutes in, given by Benjamin Bross from Fraunhofer. For Christian’s summary of all this year’s new MPEG codecs, see his previous video in the series.

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Speaker

Christian Feldmann Christian Feldmann
Team Lead, Encoding
Bitmovin

Video: The Video Codec Landscape 2020

2020 has brought a bevy of new codecs from MPEG. These codecs represent a new recognition that the right codec is the one which fits your hardware and your business case. We have the natural evolution of HEVC, namely VVC which trades on complexity to achieve impressive bit rate savings. There’s a recognition that sometimes a better codec is one that has lower computation, namely LCEVC which enables a step-change in quality for lower-power equipment. And there’s also EVC which has a license-free mode to reduce the risk for companies which prefer low-risk deployments.

Christian Feldmann from Bitmovin takes the stage in this video to introduce these three new contenders in an increasingly busy codec landscape. Christian starts by talking about the incumbents namely AVC, HEVC, VP9 and AV1. He puts their propositions up against the promises of these new codecs which are all at the point of finalisation/publication. With the current codecs, Christian looks at what the hardware and software support is like as well as the licencing.

EVC (Essential Video Codec) is the first focus of the presentation whose headline feature is more reliably licence landscape. The first offer is the baseline profile which has no licencing as it uses technologies which are old enough to be outside of patents. The main profile does require licencing and does allow much better performance. Furthermore, the advanced tools in the main profile can each be turned off individually hence avoiding patents that you don’t want to licence. The hope is that this will encourage the patent holders to licence the technology in a timely manner else the customer can, relatively easily, walk away. Using the baseline only should provide 32% better than AVC and the main profile can give up to a 25% benefit over HEVC.

LCEVC (Low Complexity Enhancement Video Coding) is next which is a new technique for encoding which is actually two codecs working together. It uses a ‘base’ codec at low resolution like AVC, HEVC, AV1 etc. This low fidelity version is then accompanied by enhancement information so that the low-resolution base can be upscaled to the desired resolution can be corrected with relevant edges etc. added. The overall effect is that complexity is kept low. It’s designed as a software codec which can fit into almost any hardware by using the hardware decoders in SoCs/CPUs (i.e. Intel QuickSync) plus the CPU itself which deals with the enhancement application. This ability to fit around hardware makes the codec ideal for improving the decoding capability to existing hardware. It stands up well against AVC providing at least 36% improvement and at worst improves slightly upon HEVC bitrates but with much-reduced encoder computation.

VVC (Versatile Video Coding) is discussed by Christian but not in great detail as Bitmovin will be covering that separately. As an evolution of HEVC, it’s no surprise that bitrate is reduced by at least 40%, though encoding complexity has gone up 10-fold. This is similar to HEVC compared to its predecessor AVC. VVC has some built-in features not delivered as standard before such as special modes for screen content (such as computer games) and 360-degree video.

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Speaker

Christian Feldmann Christian Feldmann
Lead encoding engineer,
Bitmovin

Video: 5 Myths About Dolby Vision & HDR debunked

There seem no let up in the number of technologies coming to market and whilst some, like HDR, have been slowly advancing on us for many years, the technologies that enable them such as Dolby Vision, HDR10+ and the metadata handling technologies further upstream are more recent. So it’s no surprise that there is some confusion over what’s possible and what’s not.

In this video, Bitmovin and Dolby the truth behind 5 myths surrounding the implementation and financial impact of Dolby Vision and HDR in general. Bitmovin sets the scene by with Sean McCarthy giving an overview on their research into the market. He explains why quality remains important, simply put to either keep up with competitors or be a differentiator. Sean then gives an overview of the ‘better pixels’ principle underlining that improving the pixels themselves is often more effective than higher resolution, technologies such as wide colour gamut (WCG) and HDR.

David Brooks then explains why HDR looks better, explaining the biology and psychology behind the effect as well as the technology itself. The trick with HDR is that there are no extra brightness values for the pixels, rather the brightness of each pixel is mapped onto a larger range. It’s this mapping which is the strength of the technology, altering the mapping gives different results, ultimately allowing you to run SDR and HDR workflows in parallel. David explains how HDR can be mapped down to low-brightness displays,

The last half of this video is dedicated to the myths. Each myth has several slides of explanation, for instance, the one suggests that the workflows are very complex. Hangen Last walks through a number of scenarios showing how dual (or even three-way) workflows can be achieved. The other myths, and the questions at the end, talk about resolution, licensing cost, metadata, managing dual SDR/HDR assets and live workflows with Dolby Vision.

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Speakers

David Brooks David Brooks
Senior Director, Professional Solutions,
Dolby Laboratories
Hagan Last Hagan Last
Technology Manager, Content Distribution,
Dolby Laboratories
Sean McCarthy Sean McCarthy
Senior Technical Product Marketing Manager,
Bitmovin
Kieran Farr Moderator: Kieran Farr
VP Marketing,
Bitmovin