Quantel’s QTube – Loving The Cloud

Posted on May 5, 2011 by Alex Fice

Now in your best deep brown voice, ‘Imagine a world and wherever you might be in that world you could edit footage that was kept somewhere else in that world. You could add to that footage and other people could add to it too, you could add video, voice over, edit transitions and metadata. You could do all that accurate to a single frame of video and one audio sample. In fact you could complete a programme and send it to a broadcast server ready to be aired.’

That was the 70 word pitch for QTube, Quantel’s time and space squeezing new remote media editor. This is the type of technology that some users will not want to know the workings of, because like the first time we used the Internet or a Microwave, all that most people need to know is that it works. When it doesn’t you call the IT department and go and put the kettle on.

But we are here for those who want to know.

QTube has been designed primarily for Quantel’s broadcast customers and is based on their sQ server, the prominent sector of Quantel’s market. But this is only a start and soon Quantel will be talking about QTube for other sectors and other storage devices, but let’s not get ahead of ourselves.

There has always been a demand to remotely see assets especially in quick turnaround programming like news. This isn’t new and is included alongside the heavyweight newsroom computer systems. The next step is seeing and playing media stored somewhere else, but this was and still is dependent on very powerful ‘permanently on’ network connections. These usually are Gigabit connections, but there are still latency problems inherent and computers don’t like that and get confused. Any interruption here would effectively stop the workflow.

These very high bandwidth networks are also a very expensive exercise and so have huge barriers to entry. Alright for first world countries but elsewhere might be a problem, especially if the telecoms infrastructure isn’t there. How then do you get from gigabyte connections to off the shelf ADSL speed connections that QTube is based on with all it’s mire of connection and latency problems? OK for lean back activities like viewing but lean forward for editing and you have a problem.

The answer is that Quantel has protected QTube from the pitfalls of the public Internet.

Backing QTube technology up is a mixture of Microsoft server technology and Quantel magic. Sliding backwards from the Cloud or Internet, you will find a Microsoft IIS Smooth Streaming server with security to control who has access to this content, a very important part of a system connected to potentially every online computer user. Smooth Streaming takes different file qualities for any given piece of media which it can choose from on-demand as it monitors the current Internet connection between the client and the server on a second per second basis. As we all know connections go up and down like a lift in a Hilton so Smooth Streaming expects a number of connection choices it can serve up in turn.

This is fine for a static piece of footage or programme but what about a growing news story, you can’t prepare that in to different file choices in advance. Enter the first bit of Quantel magic called Virtual Quantel Filing System. VQFS is able to produce what Quantel call mutating files, files that can change their form so that they can pretend to Microsoft that they have eight or ten different quality streams – something they are expecting to see as mentioned before. But these files don’t actually exist until they are called upon. Quantel are in fact creating only one quality in their server and this is being ‘advertised’ as being available in all those qualities but the file is only called into existence when called for. This gets around the multiple files problem. It also allows you to see all the growing files that your permissions allows you to see.

Slide back further and you have the Quantel sQ server loaded with content but also something called Frame Identity. This technology has been around for a while and is at the very basic level of a Quantel recording. Inherent in Quantel’s file format is this identity method that defines the overall clip with a unique ID but also an index number which indexes every frame and audio sample at a granular level.

For Quantel this was always a benefit internally but what happens if you expose it externally? You get a sidecar file written in XML which tells the receiving client which clip it’s receiving at that moment and which frame and which audio sample it’s receiving. Slide forward and imagine editing that file in the QTube method as once you’ve edited you have to send information back.

You don’t want to send out a 20 minute programme for an editor to receive and edit and send back because it would  take too long, so with this Identity XML method you are only sending back the instructions to edit via XML. It’s basically an ultra intelligent EDL.

The identity model is therefore independent of the quality of the media that you’re working with, it’s floating alongside it in effect. This Quantel technology is derived from an earlier product called SAM which enabled lighter weight products like Mac and PC laptops to connect with big post production systems where they may contain raw 4k files or the like. You couldn’t play those on those laptops so Quantel virtualised the media so you could play a smaller version on your laptop but with the XML file floating with it. You edit then on the laptop, send it back to the original file server to be conformed.

The Eureka moment was to mix this virtualisation of the content at different qualities with the identity model and realise that instead of taking 4k down to HD or SD they could take HD broadcast files down to a few 100 kilobits of H.264 and propagate it over the Internet using Microsoft Smooth Streaming.

It’s a lot to take in and if and when you get to a trade show you’ll hear that other manufacturers offer remote editing as well. But Quantel’s difference is their ability to work on a growing file, at frame accuracy and complete the programming in its entirety.

A ‘for instance’ to illustrate how ground breaking this technology is. Think of an international story being prepared abroad for TX in the UK, but one that needs inserts from the UK. Previous to QTube you would have to prepare the story with gaps in it where the UK bits of the story needed to go. The editing package would be sent via satellite and someone would insert the missing bits right on the stroke of transmission with very sweaty palms. With QTube the entire package is completed in one place.

In practice this all works pretty seamlessly. You have to imagine you’re in your hotel room with your laptop even though the server is next door. Quantel do actually send the files out in to the Internet so this is a real world situation of a kind. To see the mutating files mutate is quite something, they almost blink in to a higher resolution if allowed and then lower when bandwidth is a problem

Quantel also cache what’s coming in so you can shuttle backwards and forwards as if the content was all local, indeed part of it is in the cache. You then mark in and out points and start dropping shots on to the timeline in the normal way. Because of the Identity technology already mentioned, the system knows all of the content sitting behind the area you are editing. So you are able to reveal more of it and start trimming or expanding what you’ve already got. You can also treat the audio in the same way.

Hit publish when you’re finished and it creates an XML file back to the server. There are progress bars to help you see what’s happening. You are then able to ping pong versions back and forth without destruction as you are only able to perform a ‘save as’.

Quantel are still in beta with QTube and hoping to ship after NAB. The part of the process we haven’t covered is the sending back of local files. That is a simple matter of transcoding your files in a reverse way but in a store and forward transfer way.

Quantel are working on a faster way of doing this.

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