[mythtv] Freesat channel numbering

Steve Hill steve at nexusuk.org
Sun Jul 13 15:02:46 UTC 2014

I've been reverse engineering the Freesat DVB-S data carousels in order
to automatically set the channel numbers on my MythTV box.  I thought
this might be of interest to other people, so:

The code is available through Subversion:

Shut down mythbackend before running the code, since it needs access to
the DVB card.  You'll need dvbtune and dvbsnoop installed too.

Freesat does regionalisation on two levels - firstly the channels are
split into (currently) 12 bouquets:
 - England SD
 - England HD
 - England G2
 - Wales SD
 - Wales HD
 - Wales G2
 - Scotland SD
 - Scotland HD
 - Scotland G2
 - Northern Ireland SD
 - Northern Ireland HD
 - Northern Ireland G2

Within the bouquets there is some further regionalisation through
proprietary tables of region IDs.

Some gotchas I haven't figured out yet:

Some channels just don't seem to be listed in the Freesat data at all -
for example, Channel 4 and the radio stations all seem to be missing.
Maybe they're encoded elsewhere that I haven't spotted yet...

Some channels are labeled with region ID 0, and I haven't figured out
what this means.  Multiple channels seem to end up assigned to the same
channel number in region 0, and the channels often don't seem to make a
lot of sense - e.g. in the Wales SD bouquet, BBC One London, BBC One
West Midlands and BBC One South all get assigned to channel 101 in
region 0.  BBC One Wales doesn't seem to be listed at all.

If anyone has a real Freesat receiver (especially in Wales, Scotland or
Northern Ireland), I would be interested to know what regional channels
get assigned to numbers 101 and 108.

There's some further information on the reverse engineering on my blog
here: http://blog.nexusuk.org/2014/07/decoding-freesat-part-2.html
If anyone knows anything relevant about the Freesat data I would be very
interested - information seems quite thin on the ground on the internet.


 - Steve

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