Wednesday, September 06, 2017

All Change For Video Formats


It's happening again.

Every few years a new wave of technologies hits the video industry and everyone gets very excited and confused.

As a rule, evolution wins out over revolution, but in the world of video delivery things are getting complicated.

First of all it's probably explaining a little about the technology.

In order to get video from a server to a viewer of Netflix or iPlayer you usually have to encode it using an audio codec (e.g. AIF or MP3), a video codec (such as H.264) and then place it in a wrapper (e.g. FLV or MP4). Finally you have to deliver it using a transport stream such as RTMP or HLS.

And this is where the major changes seem to be coming.

There are two main drivers for the changes ahead.

First of all there's copyright - many of the codecs such as AIF and H.264 and its update, H.265 (or HEVC) are proprietary, meaning that licence fees potentially need to be paid every time you use them.

The second driver is efficiency. Ten per cent improved compression with no quality loss means tens of millions of pounds to the likes of Google and Netflix.

So, just as Flash video and RTMP delivery breathed their dying breath (largely thanks to the late Steve Jobs' aversion to Flash), with HLS and MP4 becoming an industry norm, two new battles are developing.

For video codecs it's between the proprietary HEVC and the 'open' standard AV1  The former is an evolution of the ubiquitous H.264, whilst the later is an amalgamation of Google's VP9 codec (acquired with On2) with codec fragments from other companies such as Cisco, and is surprisingly backed by the likes of Microsoft. The AV1 still doesn't have a streaming format, but Netflix are rumoured to be already using it for their download files.

Meanwhile, the battle of the transport layer is between the currently dominant HLS (HTTP Live Streaming) and the newer MPEG- DASH.  

Here there is less controversy - HLS is a very poor protocol developed by Apple to get around using proprietary competing methods for streaming video.

Both work in similar ways, but MPEG-DASH has substantial advantages and is already widely deployed by major streamers such as the BBC. 

So, it looks like the future is AV1 over MPEG-DASH. Or is it ? Google, Microsoft, Itel, AMD, Netflix, Hulu and many others are on one side. Apple is on the other. Place your bets...