[figrin_dan]

I just noticed this so thought it might be useful to check equipment.

10921H on 28E is currently showing some 1080p content. My Bush freesat HD is happy to add them in non-freesat mode.

It's a couple of disney channels.

[DragonQ]

1080p/50 or 1080p/25?

[icstm]

i assume 50 fields 25 frames?
rather than 50 frames, that would be too much.

[DragonQ]

Meh, just tested and it's 1080p/25, the same as you sometimes get on Freeview HD. Boring.

[figrin_dan]

Well as far as I know it's the first time progressive HD has been used on fta satellite channels on 28E and it is not part of the freesat spec. p/50 certainly isn't and wont be for a very long time. Expecting that would be ridiculous.

It is also not dynamic i/p switching like freeview HD

[NSMHD]

I am watching these streams via my sky+HD box, didn't think it was in the DSat spec?! There also using Dolby Digital 5.1 EX as showing up on my amp on one of the streams 4016 very interesting

[kerry]

Strange - My Panny D25 normally flags the HD channels as 1080i/50Hz. On the Disney HD tests, even though they are labeled HD, my tv just shows "wide". I didn't think the DVB/S specs for the TV included 1080p -just happy it can see & decode the 1080p, for future reference.

[Schnable]

More to the point, we have 3 HD Disney channels FTA at the moment!

That's unlike Disney.

But for how long?

[NSMHD]

Originally Posted by Schnable

More to the point, we have 3 HD Disney channels FTA at the moment!

That's unlike Disney.

But for how long?

Seems these are test video streams and actually (well defiantly not in the case of Disney channel HD) not a simulcast of the channel, so may just loop some content, to test the encoder. But it's nice to have them FTA all the same.

[DragonQ]

Well since they're 1080p/25 they're almost certainly just test channels and therefore won't be around for long.

They also show absolute rubbish.

[jzee]

Have these gone off? Can't pick up any VPID /APID?

[popeye13]

The three flagged as HD are off air now and the rest labelled after it are now encrypted in NDS VideoGuard

[NSMHD]

4016 and 4017 on 10921H are back on air , not sure if they are 1080p or not can anyone confirm?

[figrin_dan]

Yes I just noticed them. They are 1080p but they are not at double the definition of anything shown on satellite or blu-ray or the latest movies or sport as DragonQ seems to expect!

In fact they seem to be mostly upscaled SD. But as they are 1080p I thought it might be interesting to see of any set top boxes fall over.

[Martin]

4016,17 and 18 still there.

Disney HD, Disney XD HD and Disney Cinemagic HD. Nice while it lasts I suppose!

[Masteriser]

They must have gone and come back then as they certainly were not there this morning at around 9am.

[jzee]

Originally Posted by figrin_dan

In fact they seem to be mostly upscaled SD. But as they are 1080p I thought it might be interesting to see of any set top boxes fall over.

I don't know why anyone would think that they would, 1080p 25 requires less processing than 1080i 25 as no deinterlacing has to be done.

[DragonQ]

1080p/25 also requires a much lower bit rate - I'm surprised it isn't used as a way to cram more channels in a transponder/multiplex. At the same time, 1080i/25 nearly requires as much bandwidth as 1080p/50, which makes it bizarre that interlacing is still used in modern standards in the digital world.

[Muzer]

Er... no? Unless you're referring to compression, in which case there's probably a small saving with 1080p25 but I would doubt big enough for 1080i50 / 1080i/25 to be near to 1080p50.

[grahamlthompson]

Originally Posted by DragonQ

1080p/25 also requires a much lower bit rate - I'm surprised it isn't used as a way to cram more channels in a transponder/multiplex. At the same time, 1080i/25 nearly requires as much bandwidth as 1080p/50, which makes it bizarre that interlacing is still used in modern standards in the digital world.

That's just not true, 1080p25 can use a little less bandwidth than 1080i50 because it's a little easier to compress.

Both send the same amount of picture data just in a different order. Interlaced sends a frame in two fields in Europe Lines 1,3,5 ---. followed by 2,4,6-- etc. Progressive sends 1,2,3,4 --. If the two fields are derived from the same video data (like a scanned film frame) then the data you get is identical just delivered in a different order.

Anyone with a HD camcorder will tell you the bitrates required.

Full Quality Full-HD interlaced 1080i50 17Mbps. 1080p50 28Mbps. The few cameras that have 1080p25 use about 17Mbps and to be honest the footage usually looks inferior to interlaced.

All this is pretty irrelevant anyway as current HD satellite kit simply isn't capable of receiving 1080P50 so even if the extra bitrate required was found who the hell could watch it

There's very little kit currently capable of playing back 1080p50. A very few of the latest spec blu-ray players. My PS3 won't it stutters badly, you need a fast modern PC to handle 1080p50 as well. So most of us have a TV that can show 1080p50/60 but no possible source.

[figrin_dan]

Originally Posted by grahamlthompson

Both send the same amount of picture data just in a different order. Interlaced sends a frame in two fields in Europe Lines 1,3,5 ---. followed by 2,4,6-- etc. Progressive sends 1,2,3,4 --. If the two fields are derived from the same video data (like a scanned film frame) then the data you get is identical just delivered in a different order.

Surely if digital pictures were transmitted in this way then there would be no advantage over analogue. The pictures are compressed in blocks and over time, the exact order will be different for every frame.

btw They are all showing "This Morning" now

[DragonQ]

The bitrate used by camcorders (which is usually fixed by the manufacturer) is irrelevant. Check out these links:

http://bura.brunel.ac.uk/bitstream/2.../1/Fullext.pdf
http://tech.ebu.ch/docs/events/ibc11...gs_1080p50.pdf

Both suggest that 1080p/50 doesn't require a much higher bit-rate than 1080i/25, yet will obviously produce a better image. The first paper's results show that the median bit-rate saving for 1080i/25 at "excellent quality" is only 25% (and is actually negative in some cases). For "good quality" (probably equivalent to current UK broadcast FTA HD), the bit-rate saving is under 5%.

Your assertion that "1080p25 can use a little less bandwidth than 1080i50 because it's a little easier to compress" is also dubious. For example, let's take some footage recorded from BBC One HD this year (which is statistically multiplexed even though there's loads of free space on the transponder >_>). Hustle, a 1080p/25 show, was broadcast at ~5.5 Mbps. Match of the Day, a 1080i/25 show, was broadcast at ~9 Mbps. That's not a "little" less bandwidth, that's a lot less (40% less in fact).

Also, saying that 1080p/50 is harder to decode is questionable because deinterlacing requires a lot of processing power. Obviously this is normally done by the TV so isn't an issue for set-top boxes or anything.

[mwardy]

Originally Posted by grahamlthompson

Full Quality Full-HD interlaced 1080i50 17Mbps. 1080p50 28Mbps. The few cameras that have 1080p25 use about 17Mbps and to be honest the footage usually looks inferior to interlaced.

These ratios don't apply to modern coders, according to the EBU:

The compressed bit rate needed by a 1080p/50 broadcast should be the same or less than that needed by a 1080i/25 broadcast, because the use of adaptive compression is more efficient than fixed interlace compression. In other words, broadcasting 1080p/50 should, in terms of broadcast bit rates, be free to those who use 1080i/25 today.

http://tech.ebu.ch/webdav/site/tech/...tech-i_005.pdf p.9

edit: pipped by DragonQ (though this article does suggest decoding p50 is much more demanding than i).

[grahamlthompson]

Originally Posted by figrin_dan

Surely if digital pictures were transmitted in this way then there would be no advantage over analogue. The pictures are compressed in blocks and over time, the exact order will be different for every frame.

btw They are all showing "This Morning" now

You are mixing up mpeg compression with the way the original data is presented to the encoder.

Not even sure that everyone can if fact watch a true 1080p25, according the BBC a box requires a scaling ability to 1080p50 to guarantee compatibility with al TV's, Certainly some TV's had problems with dynamic switching 1080i to 1080p on Freeview.

http://www.bbc.co.uk/blogs/researcha...bc-hd-on.shtml

In regard to 1080p50, the video processing chips used in digital satellite boxes don't have the capability for 1080p50 add to that earlier HD Ready TV's only do progressive at 1280 x 720 50fps (720p) and blu-ray isn't compatible with 1080p50 there's no chance of 1080p50 broadcasts or other sources for a considerable period.

[DragonQ]

My HTPC outputs 1080p50 so uses frame doubling for 1080p25 content.