Whatever happened to surround sound for streaming Radio?
Editor's note: surround sound has history - it was first used in 1940 by Walt Disney - and in this two-part post, Alan Ogilvie reminds us that the BBC's first try at surround sound for streaming audio was back in 2002. He also hints at some plans for the future - SB.
In the first part of this blog post, I want to take you back to when Radio experimented with surround sound on the internet - namely being able to listen to a surround sound-mixed production of Dylan Thomas' Under Milk Wood (2002), and the later 'phases' of Hitchhiker's Guide (2005). It was great! "Why haven't we been doing more?", I hear you ask. Well - there is a simple answer, and you probably won't like it. The internet and the surround sound devices we needed back then just weren't widespread enough. Sure - I was able to listen to the streams we provided, but then I had all the kit necessary to handle it on my home computer... you'd expect that, what with me being the manager responsible for the infrastructure behind the encoding and streaming of the National Radio networks online. But it just wasn't really 'mainstream'.
In those years, it wasn't a foregone conclusion that your computer had the right equipment to decode surround sound audio (specifically 5.1 channel surround sound). Your computer was most likely, compared to what we have nowadays, just a bit 'clunky'. Look at the advances in the 'online' world in the last 8 years since Under Milk Wood was first made available online (and sorry - but it's not currently available to listen to again). Even your internet connection wasn't entirely 'up to it' either, this was before the internet needed to expand to support the masses using Facebook, YouTube, Twitter or iPlayer. Do you remember those days when you'd be lucky if you had broadband and it gave you 512kbps down, the majority of people online at home were only just getting over having a modem that was just slightly faster than a fax machine.
To make sure you could listen to our Radio streams, we had to go for bitrates much lower than we have today in order to keep people happy. In order to deliver the special surround sound streams to you meant that you'd need a bigger bandwidth than what was needed just to listen to regular Radio 4 output online - by only providing Under Milk Wood and Hitchhikers as on-demand streams this meant that your computer could buffer-ahead enough of this 'massive' stream for you to be able to listen to it without constant interruptions from re-buffering. Ah, how I remember waiting on my Windows Media Player on my home computer to buffer the needed amount to listen - and I lived in London with what was considered to be a good internet connection at that time. Suffice to say it didn't take off on the web... not then, anyway.
Nowadays we have better internet connections, and the devices we can connect are both more capable and more appropriate. When I say that they are 'more appropriate' I mean that when I listened in 2002, most home computers were shut away in rooms that were occasionally used by the family... now these devices are becoming part of the fabric of your home life. Just think about where your Games Console is - it's possibly in your front room, connected to a flat screen TV and you probably have a Home Cinema set-up for surround sound. Or maybe you like your audio - and have a nice surround sound capable HiFi system with the ability to stream Internet Radio services. Maybe your home computer, which now tend to come with a soundcard that supports surround sound and enough , is connected to decent speakers (because you use it to play Bluray or DVDs).
We are producing surround sound content to some extent - my colleague Simon will elaborate in part 2 about some of the challenges faced in producing the source material. So maybe we should try this again. Maybe we should take some of this wonderful surround sound audio that's being produced for Radio, and make it available online?
What would we, the BBC, need to do to make that happen? Well, luckily, we've already begun looking at Radio productions and our streaming infrastructure. There are a couple of key areas we need to clear to make this work. In order to stream surround sound online to your computer, for example, we need to get the 'end-to-end' delivery sorted. By this I mean that the surround sound mixed input from production must connect to our stream encoders, these encoders must use the correct codec and bitrate, then it has to be wrapped in the correct transport to stream it to a player on your computer which can not only decode the stream itself but can correctly play it back on your sound device. No mean feat. Especially when, if you take a look around the web, many of the 'common' services for Internet Radio, and even the video services, don't offer surround sound.
Oh, and on top of this, we'd like to do it 'live'... not just for on-demand.
Alan Ogilvie is Platform Manager at BBC Audio & Music Interactive