DS Forums

 
 

Freesat V Freeview Bit Rates


Reply
Thread Tools Search this Thread
Old 29-01-2009, 13:47
Dave Taylor
Forum Member
 
Join Date: Apr 2003
Posts: 55

Hi

Does anybody known where I can find bit rates for each channel being boradcast on both platforms.

I know that ITV1 has a higher bit rate on Freeview than Freesat but what about the other channels?

I recorded something on More 4 the other night on both platforms and I thought the Freesat recording looked better?

Is there a list?

Re Dave
Dave Taylor is offline   Reply With Quote
Please sign in or register to remove this advertisement.
Old 29-01-2009, 14:01
grahamlthompson
Forum Member
 
Join Date: May 2005
Location: Redditch Worcs
Posts: 17,289
Hi

Does anybody known where I can find bit rates for each channel being boradcast on both platforms.

I know that ITV1 has a higher bit rate on Freeview than Freesat but what about the other channels?

I recorded something on More 4 the other night on both platforms and I thought the Freesat recording looked better?

Is there a list?

Re Dave
Just look at how long the recordings are, the higher the bitrate the bigger the file. In any case bit rate is not a reliable way to test quality. Programmes with fast action will need a higher bit rate than those where the action is more sedentary and it's very dependent on the quality of the encoders that are used. Much more significant is the amount of picture information transmitted, for SD it's either 720 x 576 pixels or 544 x 576 pixels. The latter has 25% less picture info and no amount of processing can get back the missing info (ITV 1 Freeview 720 x 576, Freesat 544 x 576 pixels).
There is no definitive list as some broadcasters don't always use the same bit rate. ITV for instance shares it out between it's regions but does not always use the same share forv each region
grahamlthompson is offline   Reply With Quote
Old 29-01-2009, 14:17
b33k34
Forum Member
 
Join Date: Nov 2006
Posts: 107
...channels can also be 'stat-muxed' so that the bit rate varies between channels depending on the complexity of the picture (simplified description). That means you need to consider the 'average' of the stat muxed channels but also the other channels in the multiplex.

The current message seems to be "ITV looks worse on Freesat than Freeview at the moment".
b33k34 is offline   Reply With Quote
Old 29-01-2009, 14:31
son_t
Forum Member
 
Join Date: Jan 2006
Location: Fife
Posts: 4,038
Is there a list?

Re Dave
This post and the links in it should help a little: http://www.avforums.com/forums/8627362-post2.html

Maybe you can list a comparison summary here, after looking at the tables..?
son_t is offline   Reply With Quote
Old 29-01-2009, 16:14
White-Knight
Forum Member
 
Join Date: Dec 2008
Posts: 2,494
On the subject of quality, I took a look at Luxe.TV HD channel today (Non freesat mode).

Absolutely sublime.

Matches Blu Ray in many frames. BBC / ITV could learn a lot from them.
White-Knight is offline   Reply With Quote
Old 29-01-2009, 16:24
grahamlthompson
Forum Member
 
Join Date: May 2005
Location: Redditch Worcs
Posts: 17,289
On the subject of quality, I took a look at Luxe.TV HD channel today (Non freesat mode).

Absolutely sublime.

Matches Blu Ray in many frames. BBC / ITV could learn a lot from them.
And it uses a lower bit rate than ITV HD and much less than BBC HD.
grahamlthompson is offline   Reply With Quote
Old 29-01-2009, 16:28
jzee
Forum Member
 
Join Date: Jan 2007
Posts: 19,460
I recorded something on More 4 the other night on both platforms and I thought the Freesat recording looked better?
More 4 always seems to have a higher bitrate than most of the other C4 sat channels, presumably because they think the type of person who watches it is the more discerning viewer.... The resolution is also greater, 704 x 576, whereas all the other C4 and ITV channels are 544 x 576. All the BBC and Five channels have full 720 x 576 resolution.

And it uses a lower bit rate than ITV HD and much less than BBC HD.
Yes, 7.5 Mbps for Luxe TV HD vs about 10 for ITV HD and 16 for BBC HD. It goes to show what you can do using slower (high quality) encoding- you can see that C4 also uses much better encoding than ITV for its SD channels as C4 channels usually look better even though they often have a lower bitrate.
jzee is offline   Reply With Quote
Old 30-01-2009, 12:13
White-Knight
Forum Member
 
Join Date: Dec 2008
Posts: 2,494
whereas all the other C4 and ITV channels are 544 x 576.
Are you sure about this as my box always displays 576i which is 720 x 576 isn't it?
White-Knight is offline   Reply With Quote
Old 30-01-2009, 12:42
grahamlthompson
Forum Member
 
Join Date: May 2005
Location: Redditch Worcs
Posts: 17,289
Are you sure about this as my box always displays 576i which is 720 x 576 isn't it?
Yes sure, the 576 refers to the vertical pixel count which is always 576. The picture detail is reduced horizontally.


576i can be 544 x 576, 704 x 576 and 720 x 576.
grahamlthompson is offline   Reply With Quote
 
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search

 
Forum Jump


All times are GMT. The time now is 09:20.