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RE: CfC: to publish Media Source Extensions specification as a First Public Working Draft (FPWD)

From: Andrew Livingston <Andrew.Livingston@bbc.co.uk>
Date: Fri, 8 Feb 2013 17:44:34 +0000
To: "public-html-admin@w3.org" <public-html-admin@w3.org>
Message-ID: <F3234D24CC1DA24DAEBC22CF89D16FC506EAFA@BGB01XUD1009.national.core.bbc.co.uk>
The BBC supports the publication of the first draft of the Encrypted Media Extensions Proposal.

As both a major online distributor of video and a producer of audio-visual content the BBC has noted the discussion that has happened on the W3C mailing list over this issue, and the remainder of this message explains the reasons for our support and will hopefully be of use to the group.
About the BBC
The BBC is the world's leading public service broadcaster. Its mission is to enrich people's lives with programmes that inform, educate and entertain. Established by a Royal Charter, the BBC is a public service broadcaster primarily funded by the licence fee paid by UK households.

We use the income from the licence fee to provide services including 10 national TV channels plus regional programming, 10 national radio stations and 40 local radio stations. The BBC World Service broadcasts to the world on radio, on TV and online, providing news and information in 27 languages. The World Service is currently by a combination of Grant-In-Aid and commercial funding, with the UK licence fee replacing the Grant-in-Aid over the following five years.

The BBC also has a commercial arm, BBC Worldwide (which exploits a selection of the programmes that the BBC creates amongst other activities) as well as a number of other commercial ventures. Profits from these activities are returned to the BBC for investment in new programming and services.

With particular reference to the work of the W3C, the BBC also operates one of the world’s most popular websites, visited by an average of over 75 million unique browsers a month. A significant part of the use of the BBC website is that of online video. This includes over a million instances of short form video clips, to the BBC’s popular television and radio catch up service the BBC iPlayer, which offers online streaming of live television and full length on-demand programming.

This obviously gives the BBC a keen interest in the delivery of video online.

The BBC’s commitments to open and pan-industry standards
The BBC has a long standing commitment to the creation of open and pan-industry technology standards where practicable. This is set down in the BBC’s Framework Agreement, underneath the BBC’s Royal Charter (http://www.bbc..co.uk/bbctrust/about/how_we_govern/charter_and_agreement/). We are glad for the work of the W3C and the work of the encrypted media task force in order to look at ways to create more standardisation in this area.

The BBC also has a commitment under this agreement to make its content available on as many platforms as is reasonably practicable.  We already make iPlayer content available to several hundred different models of device, including personal computers, set-top boxes, Blu-Ray players, games consoles, video on-demand services, mobile telephones and tablets.

However, since the launch of iPlayer the amount of platforms with incompatible distribution infrastructure, video formats and security technologies has rapidly increased. This level of growth in the complexity of delivery is unsustainable, and the BBC welcomes any efforts to increase standardisation in this area in order to provide more certainty and to help us deliver better value for money for the licence fee payer.

In addition, when iPlayer launched in 2007 the market for providing online video was a very different place, and indeed we were able to cover a vast amount of use cases by providing a player utilising just one plug-in – Adobe Flash. But in 2013 the market has fragmented. Flash is no longer available on some platforms, and many mainstream market offerings no longer allow any third party plug-ins to be installed at all.

The economics of television production
The current (and indeed historic) discussions about the Encrypted Media Proposal on the W3C mailing lists have suggested that there is no need to create such a standard, as the removal of content protection technology from video content on the web is inevitable, as happened with online download-to-own sales of music tracks. We do not feel that this comparison is valid.

Television is, for the majority of viewing, a transitory medium. Whereas people listen to music tracks again and again, most television programmes are only viewed once by their audience. Because of this, the majority of television distribution historically has been via transitory means such as broadcasting linear channels via radio broadcast, rather than selling a physical medium containing the programme to consumers. Of course, some viewers do want to view a programme more than once, which is why a market of physical media sales (and now digital permanent copies) has also developed, however, this is very rarely the primary method of consumption for audio-visual programming.

This has clear benefits for most consumers. Television is generally a more expensive medium than music to produce due to the amount of labour involved, and therefore for consumers to purchase. Business models that enable content to be available to them on a temporary (or rental) basis are usually able to do so at significantly lower cost than would be the case for permanent copies.

The BBC does not believe that audience desires for these sorts of models will change with the advent of digital distribution, and therefore the need for technical means to enforce availability windows will remain in demand, both for media producers and consumers.

An example of this effect in action can be seen with the BBC’s iPlayer – by limiting the window of availability, the BBC is able to make content available for no additional fee to UK licence fee payers. Those members of the audience who wish to obtain a permanent copy can, in many cases, obtain one from the BBC’s commercial arm, BBC Worldwide, for an additional fee.. We are looking to expand availability of services such as these, as well as international distribution, with BBC Worldwide’s profits being used subsidise the licence fee and create more and better content.

Another reason why television broadcasters wish to take care over the distribution of their content is because television programmes are often compounds of many other different types of work, either original commissions or existing works. For example, many television programmes themselves contain music tracks which must be licensed from other rights holders. Many are based on existing books, or contain stills or other pieces of existing footage. Because of this, the producer of an audio-visual work is very rarely in sole control of for how long and where they can distribute it, but will need to abide by limited licences in order to obtain value for money.

Because of the issues explained above, the BBC does not feel that the requirement for content protection on online streaming video will reduce in the foreseeable future. Therefore it supports efforts to standardise as many of the mechanisms as possible in order to lower the barriers to entry and bring new solutions to the market. We believe that the Encrypted Media Proposal is a useful first step towards this.

The BBC’s requirements for a content protection system
Online video delivery is a fast moving area in which a variety of new business models are being developed all the time and technological progression can radically change the nature of the service quickly.  As such, the BBC cannot give a fully comprehensive list of requirements for a content protection system, or of those it would expect a Content Decryption Module and the Encrypted Media Proposal to deliver. Nor could we say that it would be possible for us to consider adopting such a system for our video distribution until we are able to evaluate working standards post-implementation in browsers.

However, we accept that building a specification without some idea of the requirements is impossible, so we will try to set down some of the top-level requirements that we would want such a system to deliver at the present time below. We hope that the W3C and any future Encrypted Media Task Force will find them useful to evaluate and move this proposal forward.

1) Secure delivery of online streaming video.
The proposed Encrypted Media Proposal looks to be a useful starting point. However, the BBC is unlikely to be able to use any such mechanism unless we feel that it is sufficiently secure that there would be the possibility of legal action in the event of bypassing it.

This is not an easy qualification: the W3C is an international body, and laws on bypassing technical protection measures vary significantly from country to country. In this instance the BBC would be looking for such a mechanism to be secure enough in the UK that it would be a “effective technical protection mechanism” under section 296zb of the Copyright, Designs and Patents Act 1988 (as modified by the Copyright and Related Rights Regulations 2003). We expect that other providers will look for similar assurances in their own territories, such as the anti-circumvention provisions in the Digital Millennium Copyright Act in the United States.

We also recognise that any mechanism is likely to be bypassed at some point, so we will require the Content Decryption Module to be able to securely identify itself and the version in use, so older versions that may have been compromised can be refused.

Previous discussions on the W3C mailing list have looked at if the CDM itself should be defined or mandated to be open-source. We do not believe this would be helpful, primarily because it is difficult to see how an open-source CDM would have any hope of staying secure for any length of time at all. However, we would evaluate any open-source solution that did come along fairly against our criteria, and hope that adoption of a standard like the Encrypted Media Proposal will increase the amount of vendors offering CDM modules from the number of plug-in vendors that exist today as there would be a lower cost of entry. This may enable an open-source solution that we have not yet conceived to come to market.

In addition, we feel that such a widening of the market will help content providers to be able to be more diverse in their approach, and thus avoid any censorship issues that might come about from relying too heavily on any one provider.

2) We require the ability to securely identify a type of device, and enable or disable video playback based upon the answer.
While the BBC seeks to make as much of its programming as technically possible available to all devices, the reality is that it cannot. Content from third parties in particular is often licensed for certain platforms only, and while we continue to push against this practice where possible it still exists as a requirement at this time. Because of this we will need to be able to enable or disable availability of some content based on the type of platform. The browser user agent is not sufficient for this identification. In some instances where available the device may have a secure client certificate embedded, but otherwise this feels like a role that the Content Decryption Module may be able to perform.

We appreciate that this use case will be unpopular with some, but without it there will be little chance we can practically adopt any proposal.

3) Identification of the context in which the content appears.
Within the UK the BBC website does not carry advertising, as programming is paid for by the licence fee. In the past we have encountered attempts to embed BBC streams within third party websites against our terms and conditions. These sites then attempt to sell advertising against the programming, or present other unacceptable contexts (such as presenting adult material next to children's programming). We feel that it would be helpful if the Media Source Extensions proposals had at least some level of protection against such uses and would like to work with the W3C on further refinement of the current proposals on this.

4) The ability to pass further restrictions to the graphics rendering path if available.
While we are not actively enforcing this requirement at present, the BBC notes that increasingly OS level features enable the passing of online video streaming over a network to third-party devices, in many cases with no encryption or device authentication. This would completely defeat the point of any content protection, and therefore a Content Decryption Module should be able to identify if the operating system supports such features and either flag to the operating system that it should seek a flag and enable/disable the feature as appropriate, or refuse to play the video. We feel that it would be helpful if the specification was able to specifically identify errors relating to this usage case.

It may be that there are other flags that could be useful here, and therefore the proposal should be developed to allow for the CDM to also decrypt some metadata included with the video stream. This would enable more secure delivery of these flags than identifying them entirely in the containing page where they could be modified by the user with a bookmarklet etc. The CDM should pass the results back to the browser and the operating system.

It may well be that this is a matter for the CDM implementation rather than the browser.

The consequences if a solution cannot be found.
If the W3C is unable to agree a suitable solution for protected media delivery, the BBC does not agree with previous statements by some commentators that video vendors will be forced to stream video unprotected as plugin support reduces in future browsers. Instead, the high-quality video content that the broadcast industry produces will be made available only to closed devices and application stores where such security can be implemented. In short, it will be lost to the World Wide Web entirely, and such systems have shown so far to be difficult to link to and reference for the rest of the web.. We do not believe this scenario would be positive the open web, or for anyone, either video producers or customers.

Such platform fragmentation is bound to increase development costs, and therefore restrict video to fewer platforms at higher prices. We believe this would be of detriment to the wider internet-using public.
Andrew Livingston
Rights Executive, Rights Business Development, BBC


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Received on Monday, 11 February 2013 14:06:56 GMT

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