Video

Video: Codec Comparison from TCO and Compression Efficiency Perspective

Posted on by Russell Trafford-Jones

AVC, now 16 years old, is long in the tooth but supported by billions of devices. The impetus to replace it comes from the drive to serve customers with a lower cost/base and a more capable platform. Cue the new contenders VVC and AV1 – not to mention HEVC. It’s no surprise they comptes better then AVC (also known as MPEG 4 and h.264) but do they deliver a cost efficient, legally safe codec on which to build a business?

Thierry Fautier has done the measurements and presents them in this talk. Thierry explains that the tests were done using reference code which, though unoptimised for speed, should represent the best quality possible from each codec and compared 1080p video all of which is reproduced in the IBC conference paper.

Licensing is one important topic as, by some, HEVC is seen as a failed codec not in terms of its compression but rather in the réticente by many companies to deploy it which has been due to the business risk of uncertain licensing costs and/or the expense of the known licensing costs. VVC faces the challenge of entering the market and avoiding these concerns which MPEG is determined to do.

Thierry concludes by comparing AVC against HEVC, AV1 and VVC in terms of deployment dates, deployed devices and the deployment environment. He looks at the challenge of moving large video libraries over to high-complexity codecs due to cost and time required to re-compress. The session ends with questions from the audience.
Watch now!
Speaker

Thierry Fautier Thierry Fautier
President-Chair at Ultra HD Forum,
VP Video Strategy, Harmonic

Video: Towards Measuring Perceptual Video Quality & Why

Posted on by Russell Trafford-Jones

In the ongoing battle to find the minimum bitrate for good looking video, automation is key to achieving this quickly and cheaply. However, metrics like PSNR don’t always give the best answers meaning that eyes are still better the job than silicon.

In this talk from the Demuxed conference, Intel’s Vasavee Vijayaraghavan shows us examples of computer analysis failing to identify lowest bitrate leaving the encoder spending many megabits encoding video so that it looks imperceptibly better. Further more it’s clear that MOS – the Mean Opinion Score – which has a well defined protocol behind it continues to produce the best results, though setting up and co-ordinating takes orders of magnitude more time and money.

Vasavee shows how she’s managed to develop a hybrid workflow which combines metrics and MOS scores to get much of the benefit of computer-generated metrics fed into the manual MOS process. This allows a much more targeted subjective perceptual quality MOS process thereby speeding up the whole process but still getting that human touch where it’s most valuable.

Watch now!
Speaker

Vasavee Vijayaraghavan Vasavee Vijayaraghavan
Cloud Media Solutions Architect,
Intel

Video: Simplifying the Media Workflow

Posted on by Russell Trafford-Jones

IMF is an exchange format for exchanging media between companies. Wrapping up many different versions of a programme or film into one deliverable, this Interoperable Master Format promises to reduce storage costs, to simplify workflows and, of course, to allow any company to deliver to any other.

Niklas Hammarbäck from the Nordic Entertainment Group explains how they have moved their workflows over to IMF and the benefits that has brought. Niklas lays out the problems he was trying to solve – the main one being the many different delivery formats that must be ingested. These differences create complexity and inefficiencies. The talk examines the requirements that the group developed ahead of transforming their workflows; having a single common format, for example.

This leads in to IMF which Niklas compares to baking a cake. The IMF format contains ingredients and a recipe for creating the deliverable. The ingredients in IMF are the video, audio and metadata files and the recipes are also contained in the delivery. This method allows for a video to be delivered once with several audio files. The traditional alternative would be sending the same video four separate times just with different sound.

Niklas goes in to some detail about the contents of an IMF delivery including the CPL files which are the ‘recipes’ for the media ‘ingredients’ giving examples from https://cpl.fishtank.cloud.

The talk finishes with a summary of the benefits, a check against the requirements and what has been achieved and some questions from the audience.

Watch now!

Speakers

Niklas Hammarbäck Niklas Hammarbäck
Senior Streaming Specialist,
Nordic Entertainment Group

Video: What to do after per-title encoding

Posted on by Russell Trafford-Jones

Per-title encoding is a common method of optimising quality and compression by changing the encoding options on a file-by-file basis. Although some would say the start of per-scene encoding is the death knell for per-title encoding, either is much better than the more traditional plan of applying exactly the same settings to each video.

This talk with Mux’s Nick Chadwick and Ben Dodson looks at what per-title encoding is and how to go about doing it. The initial work involves doing many encodes of the same video and analysing each for quality. This allows you to out which resolutions and bitrates to encode at and how to deliver the best video.

Ben Dodson explains the way they implemented this at Mux using machine learning. This was done by getting computers to ‘watch’ videos and extract metadata. That metadata can then be used to inform the encoding parameters without the computer watching the whole of a new video.

Nick takes some time to explain MUX’s ‘convex hulls’ which give a shape to the content’s performance at different bitrates and helps visualise the optimum encoding parameters the content. Moreover, we see that using this technique, we can explore how to change resolution to create the best encode. This doesn’t always mean reducing the resolution; there are some surprising circumstances when it makes sense to start at high resolutions, even for low bitrates.

The next stage after per-title encoding is to segment the video and encode each segment differently which Nick explores and explains how to deliver different resolutions throughout the stream seamlessly switching between them. Ben takes over and explains how this can be implemented and how to chose the segment boundaries correctly, again, using a machine learning approach to analysis and decision making.

Watch now!
Speakers

Nick Chadwick Nick Chadwick
Software Engineer,
Mux
Ben Dodson Ben Dodson
Data Scientist,
Mux