[Bradford] BBC's plan to encrypt HD content management

[Brian]

So, Steve, if understand you correctly, the frequency data would not be 
available when a scan takes place? 

Presumably, however, it would be possible to add such information manually the 
the database in, for example, MythTV. I am doing this now because BBC HD has 
changed some information such as 'symbol rate' etc. Now I have to do the rest by 
hand or rescan.
One thing I am happy about though is, for the first time, I have been able tot 
get HD working properly on all the HD channels - bar the BBC which I haven't 
been able to try yet. I am dreading the introduction of Wayland to Ubuntu which 
will probably muck everything up.

The EPG is not so important to MythTV because the data can be gleaned from 
elsewhere, so that is not any real problem for MythTV. I don't publish my 
grabber programs because I suspect that certain websites would be deluged with 
downloads, for EPG purposes, and those same web sites might  block or obfuscate 
downloads. Having said that the only one I use to any extent is one for 'Travel' 
which uses their web site so they might not object.

Brian




________________________________
From: Steve Kerr <steve at cullingworth.net>
To: BradfordLinuxUserGroup <bradford at mailman.lug.org.uk>
Sent: Tue, 28 June, 2011 1:21:07
Subject: Re: [Bradford] BBC's plan to encrypt HD content management

To quote the article: "...it is requesting that it be allowed to encrypt the 
data associated with  TV listings without which set-top boxes are not able to 
decode the TV  content". 


What they are describing there is the encryption (or obfuscation) of the DVB-SI 
and (possibly) MPEG-PSI. The STB (or other client) uses these data streams to 
find the content. The SI (System Information) describes where the service (what 
mere humans call a 'channel' - e.g. BBC1) can be found i.e. what frequency and 
other parameters to use to tune to the digital multiplex. The PSI (Program 
Specific Information) within each multiplex describes how to find the component 
parts of the service within that multiplex, i.e. the Packet IDs for the video, 
audio and other elementary streams.

The 'listings', or EPG data, is held in the Event Information Table (EIT) which 
is referenced as a component of the service in the PSI. Some service providers 
encrypt the EIT data to prevent it being used by unauthorised STBs but this 
doesn't prevent the STBs from receiving and decoding the services.

Freesat did a similar thing to prevent any standard DVB satellite receiver from 
picking up the Freesat services. In this case I think they just used a propriety 
means to describe where the services are (i.e. non-standard SI & PSI). The 
Freesat services could still be received by my media centre (non-Linux at the 
time I'm afraid) by doing a scan. The problem came when services were moved - 
they just disappeared from my media centre's perspective and I had to perform a 
manual rescan. 


.Steve



On 27 June 2011 20:23, Brian <bradlug at techchico.org.uk> wrote:

The BBC plan to introduce encryption in regard to their HD channels. It  will 
mean that existing Linux boxes  won't function anymore and that, of  course, 
will include MythTV *(see below).
>
>More information:-
>http://news.bbc.co.uk/1/hi/technology/8259154.stm
> 
>From which comes:-
>"Critics of the BBC's request say that open source licenses are  incompatible 
>with the regulations because DRM locks down software so  that it cannot be 
>altered by the user. "
>
>Ofcom:-
>http://tinyurl.com/66umlcx
> 
>
>There is a PDF on that page and in it is an email address which can be used to 
>respond to the BBC's plans via Ofcom.
>
>Put simply, as I understand it, the BBC can't encrypt the video but can encrypt 
>the EPG etc. 
>
>*If  this is all they intend to do then, as far as MythTV is concerned, it  
>won't be much of a problem as, presumably, listings can be obtained from  the 
>Net. I have written 'grabbers' for channels which aren't in the the  standard 
>EPG so the BBC should not prove any more difficult. However,  with standard 
>Linux set-top boxes this may prove a problem.
>
>Brian
>
>_______________________________________________
>Bradford mailing list
>Bradford at mailman.lug.org.uk
>https://mailman.lug.org.uk/mailman/listinfo/bradford
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.lug.org.uk/pipermail/bradford/attachments/20110628/66932991/attachment-0001.htm>