[mythtv-users] Biggest Mythtv setup

Another Sillyname anothersname at googlemail.com
Sun Apr 11 18:39:21 UTC 2010


On 11 April 2010 14:12, Alasdair Macdonald
<wewalkforonereason at googlemail.com> wrote:
> On 11 April 2010 12:56, Another Sillyname <anothersname at googlemail.com> wrote:
>
>> In the past for testing/interest I've recorded movies from both the
>> BBC and ITV using both the DVB-T and DVB-S feeds simultaneously and
>> found the same movie will have a massively different bitrate off the
>> DVB-S feed (sometimes as much as twice the DVB-T bitrate).  BBC HD off
>> Freesat currently outputs at about 6.5GB per hour, as no-one has
>> released a DVB-T2 card yet AFAIK I don't know the BBC HD bitrate of
>> DVB-T2.
>
> Not only do the DVB-T and DVB-T bitrates differ, but the bitrates for
> the BBC regions differ; of the 4 BBC2 varieties England has the lowest
> bitrate (and long GOPs); Wales / Scotland / NI have the highest
> bitrates (4297kbps) that are commonly seen of any DVB-S SD broadcast -
> although they used to be higher, up until August - ish 2009 IIRC. (At
> the same time the BBC HD bitrate dropped massively too).
>
> BBC1 comes in more varieties, but again Wales / Scotland / NI have
> higher bitrates (also 4297). The difference is noticeable, if you are
> looking for it. All of the BBC1 & BBC2 bitrates seem to be
> near-constant; all other stations that I've looked at are variable.
> BBC3 & BBC4 occasionally broadcast at even higher bitrates than the
> highest BBC1 & BBC2 broadcasts; I've even seen some BBCi (red button)
> stuff come in at 6000kbps - that's the highest I've ever seen for SD.
>
>>
>> If anyone wants to record movies from ITV off Freesat use the West
>> Country feed as it usually has the best bitrate and screen format.
>
> So this is the same principle as the variation in BBC described above.
> I wasn't aware of this particular variation; thanks for the info.
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>

IIRC the red button channels are dynamically muxed so sometimes you'll
get the bandwidth for 3-4 'stream' channels available for the one
channel that's transmitting and the bandwidth goes up accordingly.

I remember on one occasion I recorded a late movie on BBC 1 SD off
freesat and it was almost 4.5gb per hour....that's approaching HD
bandwidth and usually a BBC 1 SD recording runs to about 2.5GB per
hour.

Sad really, I should get out more!!


More information about the mythtv-users mailing list