[mythtv-users] How the BBC's HD DRM plot was kept secret .. and why

Lawrence Rust lvr at softsystem.co.uk
Wed Nov 16 14:10:00 UTC 2011


On Wed, 2011-11-16 at 06:56 +0000, Tim Draper wrote:
> On 15 November 2011 19:39, R. G. Newbury <newbury at mandamus.org> wrote:
> > This should be quite worrisome for an mythtv users in England.
> > The BBC wants to DRM lock its broadcasts.
> >
> > From:
> >
> > http://www.guardian.co.uk/technology/2011/nov/14/bbc-hd-drm
> >
[snip]
> would this not be similar to how sky/satellite FTA works with their
> subscription cards; scrambled data and the hardware to decrypt it is
> kept a trade secret?

In the UK all DVB-S/S2 FTA channels, with the exception of some ITV and
Channel 5 regions, are unencrypted.  By law, as stated in the article,
all BBC transmissions must be unencrypted.  Before the advent of
Freesat, the BBC provided a free card to UK residents to decrypt Free To
View channels using a Sky box without a subscription.  Out of contract
Sky cards also provided the same benefit.

> You can buy hardware for satellite transmissions (seems a grey area
> here, due to possible illegal usage)

Certainly not illegal.

>  and it works on mythtv though.
> i'm not sure if DRM is used on sky - i know encryption is though.

Sky+ recordings are stored encrypted.

> also, how would the majority of existing customers receive the content
> - would they need to upgrade their 1 year old freeview-HD TV as it
> will unlikely handle the DRM instructions

Many older supposed HD-compatible TV's and STB's don't implement DVB-T2,
so they can't receive BBC HD.  So they won't be affected.  You'll need
to buy a new STB which will have DRM.

>  (i presume hardware decoded
> DRM), or would a CI-type device be used? if so, surely it wouldnt be
> long before there are drivers available for linux...

Not to worry, MythTV currently includes the Huffman tables to decompress
the EPG.  The algorithm to decode the Freeview HD EPG is identical to
that on DVB-S:

http://forums.digitalspy.co.uk/showpost.php?p=47154962&postcount=14

> asmuch as i dont like DRM, and will actively seek none DRM material
> (legally!), i think it's going to end up being implemented by more
> companies over the next number of years.

-- 
Lawrence


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