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BBC iPlayer Goes H.264

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Anthony Rose Anthony Rose | 16:50 UK time, Tuesday, 12 August 2008

The BBC iPlayer team works hard to release new versions of the BBC iPlayer frequently in its bid to make it as widely available as possible across different devices and to come up with the most exciting new features.

Though not as sexy, the team also has to address the [inevitable] bug fixes. Over the past six months we added Flash streaming (Dec), added Most Popular, More Like This, etc. (Jan), and made BBC iPlayer available on iPhone (Feb) and Wii (April).

We then went quiet for a while as we built an all-new server architecture better suited to powering the types of product propositions that we look forward to releasing over the next six months.

iceberg.jpg
An iceberg seen from off the coast of Graham Land in Antarctica

The first of the releases built on our new platform - the all-new BBC iPlayer 2.0 site - went live on June 25, just over a month ago.

Like an iceberg, the BBC iPlayer 2.0 site is the bit "above the water". The new site is doing well, but to me more important than the site itself is the ability that our new architecture (the invisible mass below the water) gives us to deliver innovative and world-class new features, even faster than we've been shipping them so far.

Okay, now on to the announcement: H.264.

The video you see in BBC iPlayer today is encoded using the On2 VP6 codec, at a bitrate of 500Kbps. The On2 codec (a video compression technology from a company called On2) is pretty much the standard for video delivery over the internet today. It's optimised for moderately low data rates (300Kbps to 700Kbps, rather than the 2Mbps to 4Mbps needed for HD content), and low CPU usage, allowing it to work reasonably well on older computers. In short, On2 VP6 is the video workhorse of the internet.

When we went live with streaming in BBC iPlayer back in December last year, we needed to make some decisions about the streaming technology to use. Adobe Flash with On2 VP6 codec was the obvious technology choice (it's also used by YouTube and most other video sites), because evryone already had Flash installed, meaning that nobody would need to install anything in order to use BBC iPlayer - an important criterion.

Choosing a bitrate was more difficult: too low and the resulting video quality would be unacceptably poor; too high (with corresponding higher bandwidth) and people on lower bandwidth connections would experience buffering problems - ie, pauses in playback that reduce your viewing pleasure. I think we chose well, hitting the right spot between quality and bitrate and giving a good quality playback experience, at least when playing back within the playback "window" on the BBC iPlayer web site. However, the full-screen experience was less than optimal. As the majority of BBC iPlayer users watch BBC iPlayer in full-screen mode, this is clearly something that needs to be addressed.

Enter H.264.

H.264 is a high-performance video compression technology - the new kid on the block, so to speak. It's actually been around for a few years, but only recently have a few things come together to make H.264 usable by us. Compared to On2 VP6, H.264 delivers sharper video quality at a lower data rate, but requires more CPU power to decode, particularly on older machines, and the user needs to have the latest version of Flash installed.

Back in December of last year, relatively few people had installed the Flash player needed to play H.264 content; now almost 80% of BBC iPlayer users have it. More machines now have graphics cards with H.264 hardware acceleration. Additionally, Level3, a content distribution network (CDN) is now able to stream H.264 content to ISPs in the UK, and the content encoding workflows that we use (Anystream and Telestream) are now able to support H.264.

Actually, when I say that our content encoding workflows are now able to support H.264, that's not quite correct yet. Our compression technology suppliers are frantically working on getting the preferred MainConcept H.264 compressor into their software, something they're hoping to complete in the next week or two. In the meantime we're using the QuickTime codec, which produces results that are acceptable, but not as good. So it seems we're really on the leading edge here.

Anyway, to cut a long story short, the good news for those looking for video quality improvements in BBC iPlayer is that, starting this week, we're going to be encoding our content in H.264 format at 800Kbps. Additionally, our media player now supports hardware acceleration in full-screen mode, giving a greatly improved image at lower CPU usage than before.

Along with the change to H.264, the soundtrack in our video programmes is changing to AAC+, another new compression technology that delivers better sound at a lower bitrate. The bass is deeper, the treble tighter, the overall effect is a noticeably better listening experience, particularly if you listen with headphones or hook up your computer to your TV or home sound system.

However, given that we're on the (leading) edge here, with our CDN network and video compression partners only now being able to support our requirements, we're going to play it safe and introduce H.264 in two phases:

In the first phase, starting this week, we're going to create our content in both On2 VP6 and H.264 format, and provide a button to let you choose which works best for you and your internet connection, Normal or High:

iplayer_quality.gif

Initially, the default will continue be On2 VP6, which will remain the choice for users on slower internet connections. However, if your internet connection speed is 1Mbps or higher, try the "HIGH" H.264 version.

In the second phase, we're going to add automatic bitrate detection, so that our media player software automatically chooses the right version for your computer and internet connection speed - we'll likely introduce this auto-detection feature in September. This will make it as easy as possible for all users to get the best quality of service possible with the equipment they have.

Initially the H.264 option will only be offered to people who have the latest version of Flash installed, and will be offered incrementally as new content rolls out through our encoding chain. We'll also be making a number of tweaks and enhancements over the coming weeks as our video compressor suppliers deliver more software updates, so look out for further improvements over the next few weeks.

On a different topic, the BBC iPlayer has been shortlisted for three British Technology Awards - Best Home Entertainment, Most Indispensable Technology and Best Online Technology. The winners are determined by popular vote here. All votes for BBC iPlayer are much appreciated :)

Anthony Rose is Head of Digital Media, BBC Future Media & Technology.

Comments

  • Comment number 1.

    Great news but this technology has been available for years. The addition of H264 to the Adobe Flash player is more recent though. There is a very high quality freeware encoder called X264 which could be used. It is a pity you chose the quicktime encoder which is not highly regarded. So your initial tests are not going to be very useful.

    Are you going to use AAC or AAC+ for your radio on the Iplayer. I was hoping you would use AAC at 128kbps which would give the same quality as Itune downloads. This would illustrate to people how bad DAB radio quality is so you may not be alowed to use it for political reasons.

    How about some HD streams. Vimeo already does this 1280x720 pixels at up to 5Mbps and the results are fantastic.

  • Comment number 2.

    Moan moan moan. Can't you just be happy that the quality is getting better?

  • Comment number 3.

    I don't know how excited it's possible to get over codecs, but this increase in quality is certainly good news.

    It's a bit off-topic (sorry!), but I noticed I was able to watch Spooks:Code 9 on iPlayer with subtitles last night, which was a very welcome improvement. I'm surprised you haven't even mentioned it yet - it's a big step forward, especially for those of us not running Windows who can't download subtitled versions.

  • Comment number 4.

    Certainly good news. Of course, being able to download in H.264 would be much appreciated, but I'd guess that's out of the question - for now.

    How about further increasing the resolution, as well as the bitrate?

  • Comment number 5.

    Also, how about making more content available for the iPhone? I sometimes find that almost everything I want to watch is "unavailable"...

  • Comment number 6.

    Is this new codec going to be compatable with the Nintendo Wii? Seeing that, unlike pc users, Wii users will often be viewing the iPlayer on 32"+ screens it would be hugely appreciated.

    On the same topic, how far off is the release of the proper Wii iPlayer? Since you updated to 2.0 the experience on the Wii (in my opinion) has actually gotten worse

  • Comment number 7.

    Can't see H264 being supported on Wii in the near future, as the Wii only runs Flash Player 7, but Flash 9.115 or greater is needed for H264.

  • Comment number 8.

    Has this feature been removed then because no videos on the Iplayer have a button allowing for higher quality video.

  • Comment number 9.

    It was available for about (half) a day, but seems to have been pulled again along with the ability to sort programs by date.

    Hopefully they'll be back soon :( .

  • Comment number 10.

    How is the H.264 files delivered? By progressive download or real streaming? If streaming, are you using the Flash Media Server?

  • Comment number 11.

    Pity that you don't support BBC HD programs - the BBC seems to spend a lot of money on many things that strikes their fancy, but when you have a great channel like BBC HD but fail to show it in your listings and supüport a full channel program - yes the olympics is great in HD but you had to do that - even Eurosport has a better offering, and afterwards you will go back to sleep.

    Can you support what you have rather than technology tinkering with iplayer.

    A frustrated BBC HD watcher - when there is a program to watch - other than BBC HD preview

  • Comment number 12.

    whilst all these improvements are welcome when using the iplayer on a Mac it still has a tendency to freeze , in fact radio broadcasting has got a lot worse since the iPlayer has been introduced

  • Comment number 13.

    lordmedkit - I've been told that H.264 should be up and running again sometime today.

    Nick Reynolds (editor, BBC Internet blog)

  • Comment number 14.

    I absolutely agree i-player as far as radio is concerned is very inferior to real player for listen again. I had not realised having a mac was a factor. In fact for most radio programmes I can only get the intro on listen again before it freezes and then I can resume in bites of 3 minutes or less. This is intolerable. I don't see any improvement at all.

  • Comment number 15.

    Great, well done for catching up. Now how about removing your sneaky kontiki peer2peer software??? Or giving people the option of watching the content without supplying it to the rest of the world without knowing?

  • Comment number 16.

    CrymynylMynd - the option to stop peer to peer file sharing is already available on the iPlayer. See this link.

    Nick Reynolds (editor, BBC Internet blog)

  • Comment number 17.

    Great news on the H.264, though would like to report a bug.

    Under linux the framerate for flash video has always been sketchy compared to windows / OSX, with each new beta realease of Flash 10 comes vast improvements (In normal flv and H.264 video) Though the iPlayer seems not to recognise Flash 10 as H.264 capable, though works fine under 9.

    Could the detection process be updated to include this version?


  • Comment number 18.

    Dnoles - I have been told by our technical team that this is a known bug that we are in the process of fixing.

    Nick Reynolds (editor, BBC Internet blog)

  • Comment number 19.

    Nick,

    Fair point, I suppose I should investigate things myself before I post comments. My worry is that I, like most people, don't tend to read the notices in installers. Its usually just Next, Next, Next, Next, Finish. For the not so IT savvy out there, the software would be installed and Kontiki would be lurking in the background, using system resources and upstream bandwidth and those people wouldn't know where to begin to try to fix a problem like that. I won't pretend I know the inner workings of BBC iPlayer or Youtube BUT on the surface, youtube are able to supply video to everyone using their own servers, not their users computers. I think the peer2peer side of things should be disabled/removed and maybe provided as a seperate download for those who actually want to let the BBC use their bandwidth to distribute media. How many people would download it? Probably none. The point I am rambling to is that the non-IT savvy or not so careful users are made to install software that has a negative impact on their system and internet performance to help out the BBC who should be spending more money that they collect in license fees on more servers or faster connections to distribute the video. I have no problem with p2p but do it off your own back, don't automatically use your viewers.

    I have another rant about you lot running Teletext after a certain time at night instead of some of the decent programmes you have collecting dust in the BBC archive!!! If I want to see Teletext, I know where the button is!! That one isn't for here though... Saying that, you don't run Teletext on the iPlayer so thats all good.

    Cheers

  • Comment number 20.

    Does this increase the chances of iPlayer being available on Apple TV? It's disappointing it's still considered a "hobby" device even by Apple, it's a fantastic box. I wouldn't deliberately buy a whole season of something on iTunes to watch it on this, but I do very often dip in and out of shows, either to see episodes that I enjoyed again, or one that I've missed. Anyway, my point is, partnering with Apple and making this an option via the 'TV Shows' menu would be fantastic. I guess, though, they don't want any competition to their revenues through people purchasing shows on the same box - though I'd argue that I'd be more likely to go buy old series of stuff I've just watched, or maybe they could add a feature to 'bookmark' something once watched on iPlayer so you later get alerted when its on sale via iTunes.

  • Comment number 21.

    The sound level is noticeably higher on the new whizzy high quality streaming ... a good thing.

    And yes - caspararemi - would be great to see iPlayer being integrated with Apple TV.

    And maybe they'll get around to introducing series passes for downloads too.

  • Comment number 22.

    @trevorjharris. it says quicktime is an interim solution while they wait for MainConcept encoder to be integrated in their workflow.

  • Comment number 23.


    trevorjharris asked "Are you going to use AAC or AAC+ for your radio on the Iplayer. I was hoping you would use AAC at 128kbps which would give the same quality as Itune downloads. This would illustrate to people how bad DAB radio quality is so you may not be alowed to use it for political reasons."

    We'll be using AAC+, at a range of bitrates designed to complement the audio content while being conservative with your available bandwidth.

    In terms of your other point, the current flash streams on iPlayer listen-again already equal or exceed the bitrate of our DAB broadcasts, and use the more efficient MP3 codec instead of DAB's MP2. There are no political footballs here - only the wish to give you the best quality.

    James Cridland (BBC Audio and Music Interactive)

  • Comment number 24.

    If AppleTV supported iPlayer, I would buy one this evening. I don't suppose, though, that Apple UK have the means to sponsor/bribe the BBC to develop this.

    Anyway, just thought I'd like to offer encouragement. I think you guys are doing a good job and it's worth pushing money in this direction.

    Alex

  • Comment number 25.

    Great news on the video side of things!
    Any updates planned to the iPhone (or other 'web based' players; the PS3 for example) clients - specifically are there any plans to enable the radio stations on such devices?
    If so would you allow the iPhone client to stream radio over the phone network?

  • Comment number 26.

    Good to see hardware video acceleration supported with the new codec, any chance this can be applied to the lower quality streams? Finally fullscreen is watchable on PCs with decent graphics cards that don't have new 2Ghz processors

  • Comment number 27.

    This is good news. However as a Mac user, the fact that Adobe's Flash player sucks so incredibly hard is a fly in the ointment - my computer may melt while trying to play this back! Obviously not your fault, but any possibility of a better delivery medium in the future would be so awesome.

    Speaking of third party software which sucks, is there any chance that live radio will change to a better format in the future (eg.: an mp3 stream)? RealPlayer is getting more and more broken on Macs (it can't be used in hidden browser tabs, for instance) and Windows Media support is diabolical at best...

    (It's not as though piracy should be a real concern, what with every BBC programme being available on sharing networks from other sources, anyway).

    The improvement in the iPlayer services is definitely a step in the right direction, though! Thanks!

  • Comment number 28.

    H264. What a shame. Why didn't you use this opportunity to use Dirac, given the BBC's investment in this superior technology? Is it simply not ready for mainstream yet? I do hope the sheep like adoption of H264 will not mean that yet another superior technology will be lost along the way. Particularly as Dirac align's so well with the BBC's philiosphy on Open Standards - a quote from the BBC Dirac web pages "There are compelling economic reasons for content providers to adopt a free, Open Source codec. Any organisation wishing to serve large volumes of video content will find the use of Dirac a significant cost saving. This was part of the BBC's initial motivation for developing Dirac. It also avoids the bureaucratic licensing conditions associated with proprietary codecs"
    So Dirac is not only capable of delivering a superior video Consumer experience, it's free from commercial encumbercance.

  • Comment number 29.

    that should of course read "encumbrance"

  • Comment number 30.

    Sounds good! Will this be rolled out to the EMP also?

  • Comment number 31.

    That's great . This means increasing picture quality and faster data rates. which is always been main factors

  • Comment number 32.

    I'm somewhat concerned about BBC's move away from using their own infrastructure to stream content to users. With peering the cost’s to the ISP (and BBC) is considerably lower as there is not the per mbit cost associated with using a provider like Level(3). While I understand that the traffic levels involved are likely to be massive (one provider has pointed out that they are getting ~1Gbit/sec of traffic just from iPlayer usage) the costs to them are going to go through the roof.

    In the sake of open information what was the reason behind moving to Level(3) (Who pretty much point blank refuse to peer with anyone that isn’t a Tier 1) for your CDN?

    Regards,

    Alex

  • Comment number 33.

    As Alex Smith mentions above and as identified in an article in The Register (http://tinyurl.com/5otbnz%29 the BBC's move of CDN from Akamai to Level3 is likely to be an onerous one for small and medium-sized ISP's due to increased costs for content delivery.

    What assurances can Anthony Rose give the British public and smaller UK-based ISP's (including Zen who are no small minnow) that this change of CDN will not adversely affect them and ultimatelt the viewing audience?

  • Comment number 34.

    chip_scooter - if you read Anthony's post carefully I don't think he said the BBC was moving from Akamai to Level 3 - he uses the word "additionally".

    You may find this blog post of interest.

    Nick Reynolds (editor, BBC Internet blog)

  • Comment number 35.

    All this talk of improvements, yet I can watch identical clips on iPlayer or on Youtube and still find Youtube to be infinietely superior.

    I use an Apple iMac with OSX 10.4 and a very stable ADSL connection that gives me 2meg pretty much all the time.

    Anyone with a Mac, I encourage you to try this out and post your experiences here. Doctor Who is a good source for clips that are hosted within bbc.co.uk and also on the BBC's Youtube channel.

    The iPlayer buffers for ages, plays a few seconds, then stalls and buffers for another age. It gives no on-screen cue whatsoever of how much it is buffering, unlike Youtube's implementation of the flash player which shows you exactly what it's up to and also gives you the chance to jump around within the clip.

    I was never very enamoured with the BBC's RealPlayer-based service but at least it was functional. Now any content delivered via iPlayer is effectively off limits to me.

    And of course there's *still* no downloadable, p2p version of iPlayer available for Mac. Aren't you in violation of some sort of ruling from the BBC Trust on this by now, or are you still managing to dodge it by reporting 'progress' every six months?

    I dislike the 'other' means of acquiring BBC content over the internet but at the moment you're giving me very little choice.

    Yours, one extremely frustrated Mac user and BBC fan.

  • Comment number 36.

    Very useful information

    As someone who uses iPlayer, and maintains a website, it's useful to know what codecs are suitable for the majority of users out there.

  • Comment number 37.

    The high quality version looks good! Just wonder if this transcoded in High Profile Level 3 like content on the Blueray disc?

  • Comment number 38.

    I'm disappointed, although not very surprised, at the lack of acknowledgement or official comment of the issue I posted here two months ago.

    Looks like these blog entries are mostly one-way traffic, with BBC experts telling us how things are going to be but apparently taking little note of feedback (or if they are noting it, not stooping to respond to it).

    Meanwhile, I can still watch a BBC clip reliably on Youtube any time of any day, but not via iPlayer, and if I want to watch entire programmes at my leisure, that I missed and failed to record, I have no choice but to ponder what 'alternatives' might be available.

    Pity.

  • Comment number 39.

    @christownsend

    The iPlayer streaming service doesn't "buffer" at all - it doesn't buffer anything in advance to prevent pirates ripping the Flash stream as per the BBC's rights agreements (one would note that YouTube's streams are trivially easy to capture, and the only reason they allow buffering is because almost all their content is illegal and pirated in the first place…). However, you can still jump around the clip exactly the same as YouTube, and frankly you should still be able to watch the stream without any interruption so the problem is likely with your ISP not having very good peering with networks like Akamai who serve the iPlayer streams.

    I'm able to watch them perfectly well on my Macbook, using way less than 2 mb of bandwidth. I would get a better ISP.

    As for the download service, it's already been announced that it's coming in the next seven weeks, and is going to be using Adobe AIR (it's been built very quickly considering when AIR got released). The delay is frankly Apple's fault for not licencing out Fairplay in an anti-competitive manner.

  • Comment number 40.

    @ post 37, bluray's are encoded in High Profile leve 4.0 not 3.0 as far as i'm aware.

    Not sure if using mainconcept's encoder is the best option, firstly x264 (open source) is overall a little better, both have advantages over the other, but x264 is free and open source so creating iplayer would be easier with the source code and its free of course. AAC is a good choice, no complaints there.

    Hopefully you will have HD downloads of 1280*720p in h264+AC3 in the future, would be great to download them to pc rather than just stream. Obviously the bandwidth cost is a big factor in that.

  • Comment number 41.

    Phazer, do you think there might be peering issues between my ISP and the BBC then? Because I can watch a clip from the BBC's presence on YouTube almost instantly, at any time of day; it very rarely even depends on YouTube's ability to buffer (and thank you for your explanation of that, I'd not appreciated the reason).

    Doctor Who trailers are always a good test because it's normally easy to find the same clip on both the BBC website and on YouTube. Invariably the YouTube version works better, and that's the same time of day, same bandwidth, same Mac, same everything.

    My ISP is Virgin Media (their off-net ADSL service).

  • Comment number 42.

    I have the same issue with SKY Broadband - I get 15 seconds at a time - then it freezes for about 10 seconds - then starts again - any ideas?

  • Comment number 43.

    Finally fullscreen is watchable on PCs with decent graphics cards that don't have new 2Ghz processors. http://www.birsesver.com

  • Comment number 44.

  • Comment number 45.

    This comment was removed because the moderators found it broke the house rules. Explain.

 

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