September 2016

The Future of Media Files: They’re Big and Getting Bigger

Jon Hatto

Media files are big and they’re getting bigger. The industry adoption of 4K and Ultra HD is quickly confirming that. Now, even my phone shoots 4K video and this chews up its internal storage at a frankly ludicrous rate. Shaky footage from my son’s sports day now means I haven’t got enough free space to get the latest update to ‘Clash of Clans’. Truly a first world problem – but one that is being worked on.

First, we need to understand how media files are constructed, so let me try and explain by way of the menu at my local Subway sandwich store. Every media file has a container, otherwise known as a wrapper, such as MOV, MXF or MP4. Think of this as the bread in our Subway sandwich (for info, the writer is inclined towards the Italian Herb). Without the bread, there is no sandwich and in the same way, we can’t have a media file without a container. However, we wouldn’t go into Subway and order only bread. This is where the filling comes in, or in the case of our media file, the codec. Just as our Subway sandwich can have a multitude of meats, toppings and sauces, so our media file wrapper can contain any one of a multitude of different codecs.

In Subway, you can choose from a number of fillings such as the Spicy Italian, Steak & Cheese, or the Meatball Marinara (this writer’s favourite). With video files, you may commonly find codecs such as h.264, MPEG2, ProRes or DNxHD; for audio, it might be PCM, AAC or FLAC. Each codec has its uses, depending on whether it’s in acquisition, post production, distribution or, for example, streaming onto a tablet at home. There’s over 3,000 combinations of wrapper, codec and video format in common use today. In the interests of completeness, the writer calculates that Subway offers 38,080 permutations of their Sub menu. Just wow...

"It’s becoming more important than ever to compress video files down to smaller sizes, whilst maintaining sufficient quality for their intended purpose."

So, back to our ‘Clash of Clans’ update problem. With the explosion in both the use and size of video data, it’s becoming more important than ever to compress video files down to smaller sizes, whilst maintaining sufficient quality for their intended purpose. This has the notable benefits of reducing storage space and lowering the bandwidth required to move the file around. Most codecs offer differing levels of compression, allowing users to trade quality for smaller file sizes.

The continual advancement of codec technology, in conjunction with more powerful computers, is allowing us to fit ever higher quality video into less space. As a case in point, it’s seen as crucial that the h.265 codec must succeed in order to allow the take-up of 4K and Ultra HD to continue, as without it broadcasters won’t be able to efficiently transmit this higher-quality video to the home. As video quality continues to improve, media files inevitably get bigger, and so the technology to compress media files to more manageable sizes need to keep up.

In my case, just because my phone has a 4K record option, it doesn’t necessitate its selection...