Question about SKY HD quality

Paul1021 · 19-10-2006, 12:10

I have just had sky hd installed, but I have not yet purchased my hd tv yet.
At the moment I have a panasonic 36 inch 100 htz tv.
Without a doubt the picture I am getting through the hd channels is better even though it is only connected thru scart.I know its not hd but can anyone tell me why the picture is better, I have noticed that the football broadcasts do not have the compression like aura around the players that you get with normal sky.I would be interested to hear any comments

Wicked_and_Crazy · 19-10-2006, 12:24

Quote:

Originally Posted by Paul1021

I have just had sky hd installed, but I have not yet purchased my hd tv yet.
At the moment I have a panasonic 36 inch 100 htz tv.
Without a doubt the picture I am getting through the hd channels is better even though it is only connected thru scart.I know its not hd but can anyone tell me why the picture is better, I have noticed that the football broadcasts do not have the compression like aura around the players that you get with normal sky.I would be interested to hear any comments

Sounds like i have the same tv as you! Its because HD sends more scan lines per frame and your TV is able to cope with these. Your TV was too good for the number of scan lines it was receiving before.

Does anyone know if HD is interlaced or not?

Stuart · 19-10-2006, 13:34

HD can be either Interlaced or Progressive. If you see the vertical resolution expressed with an i at the end, it's interlaced.

I'm pretty sure that all the low-end (<Ãƒâ€šÃ‚Â£5000) Hi Def equipment will be interlaced.

TheBlueRaja · 19-10-2006, 15:35

Its interlaced, Sky HD runs at 1080i. (the i is for interlaced).

Paul1021 · 19-10-2006, 16:19

Thanks for the info.It was a nice surprise cos I did not expect to get any improvement untill I bought a new T.V.

TheBlueRaja · 19-10-2006, 17:08

Actually just to clarify my last statement Sky HD is broadcast at 1080i as standard, however i believe the box can be set to quite a few standards (720P for example)

21-10-2006, 21:50

Quote:

Originally Posted by Paul1021

I have just had sky hd installed, but I have not yet purchased my hd tv yet.
At the moment I have a panasonic 36 inch 100 htz tv.
Without a doubt the picture I am getting through the hd channels is better even though it is only connected thru scart.I know its not hd but can anyone tell me why the picture is better, I have noticed that the football broadcasts do not have the compression like aura around the players that you get with normal sky.I would be interested to hear any comments

The HD broadcasts are done with MPEG4, there are more tools available with this. The way artifacts are handled by it is different with in loop deblocking filters. So I'd say the reason your pics look better is due to this.

andygrif · 22-10-2006, 22:36

Quote:

Originally Posted by Paul1021

I have just had sky hd installed, but I have not yet purchased my hd tv yet.
At the moment I have a panasonic 36 inch 100 htz tv.
Without a doubt the picture I am getting through the hd channels is better even though it is only connected thru scart.I know its not hd but can anyone tell me why the picture is better, I have noticed that the football broadcasts do not have the compression like aura around the players that you get with normal sky.I would be interested to hear any comments

I'm not a huge expert on these things, but it's not surprising that the picture quality is better. The amount of bandwidth that HD requires is of course much greater than standard broadcasts, as well as using a different encoding algorythm. The usual Sky channels are very much subject to blockiness and artifacts, so this would be less pronouced on HD.

Of course, you'll get the full benefit, as you know, on an HD TV.

What is interesting is that watching standard Sky channels on an HD TV really shows up the poor quality of the system in comparison - which is my main reason for not buying an HD TV right now.

Womble · 23-10-2006, 09:00

Man, we have been conned!!!! When it was Analogue, you got an 8mhz channel all to one channel ie Sky Sports 1. You could see the players faces, and those of the crowd. Then, we are "given" digital, They said the picture would be better, so they crammed upto 7 channels down 8mhz of bandwidth. This resulted in............... wait for it......... crap pictures that lacked definition. Ahhh they say you need HD TV!!! But pay us more money, and go to our sponsers/partners and buy an HD TV, there now you have good pictures!!!!

I've been had, Sky, NTL/TW greatest con trick ever!!!!!!!

Wicked_and_Crazy · 23-10-2006, 09:03

Quote:

Originally Posted by Womble

Man, we have been conned!!!! When it was Analogue, you got an 8mhz channel all to one channel ie Sky Sports 1. You could see the players faces, and those of the crowd. Then, we are "given" digital, They said the picture would be better, so they crammed upto 7 channels down 8mhz of bandwidth. This resulted in............... wait for it......... crap pictures that lacked definition. Ahhh they say you need HD TV!!! But pay us more money, and go to our sponsers/partners and buy an HD TV, there now you have good pictures!!!!

I've been had, Sky, NTL/TW greatest con trick ever!!!!!!!

You cant compare analogue and digital in terms of bandwidth

Stuart · 23-10-2006, 11:39

Quote:

Originally Posted by Wicked_and_Crazy

You cant compare analogue and digital in terms of bandwidth

No, you can't compare them directly. However, reducing bandwidth does directly affect the quality of a digital signal. If you compared an uncompressed digital signal with an Analogue signal, most people would say that the digital signal is better. As soon as you compress it, the quality may be better or worse depending on the encoding and bandwidth used.

23-10-2006, 13:07

Quote:

Originally Posted by Womble

Man, we have been conned!!!! When it was Analogue, you got an 8mhz channel all to one channel ie Sky Sports 1. You could see the players faces, and those of the crowd. Then, we are "given" digital, They said the picture would be better, so they crammed upto 7 channels down 8mhz of bandwidth. This resulted in............... wait for it......... crap pictures that lacked definition. Ahhh they say you need HD TV!!! But pay us more money, and go to our sponsers/partners and buy an HD TV, there now you have good pictures!!!!

I've been had, Sky, NTL/TW greatest con trick ever!!!!!!!

It was only 8MHz on Cable, satellite uses 28MHz or so channels.
I'd also say 7 channels per mux is on the low side.
HD has the capacity to show far greater detail than analogue ever could, if its given enough bitrate. The second generation of encoders are coming out now as well, so pictures will improve.

Womble · 23-10-2006, 16:54

Quote:

Originally Posted by Stuart C

No, you can't compare them directly. However, reducing bandwidth does directly affect the quality of a digital signal. If you compared an uncompressed digital signal with an Analogue signal, most people would say that the digital signal is better. As soon as you compress it, the quality may be better or worse depending on the encoding and bandwidth used.

My point exactly!! And you know as well as I do they will compress it to death

---------- Post added at 16:54 ---------- Previous post was at 16:53 ----------

Quote:

Originally Posted by Creative

It was only 8MHz on Cable, satellite uses 28MHz or so channels.
I'd also say 7 channels per mux is on the low side.
HD has the capacity to show far greater detail than analogue ever could, if its given enough bitrate. The second generation of encoders are coming out now as well, so pictures will improve.

So, How many uncompressed digital channels could you put in a mux?? (just out of interest)

23-10-2006, 22:20

Quote:

Originally Posted by Womble

My point exactly!! And you know as well as I do they will compress it to death

---------- Post added at 16:54 ---------- Previous post was at 16:53 ----------

So, How many uncompressed digital channels could you put in a mux?? (just out of interest)

An uncompressed SDI video signal is 270Mb/s. An uncompressed HD SDI video signal is 1.5Gb/s
A satellite Mux is 34 and a bit Mb/s A cable Mux is 38 and a bit Mb/s

andygrif · 24-10-2006, 09:30

Quote:

Originally Posted by Womble

Man, we have been conned!!!! When it was Analogue, you got an 8mhz channel all to one channel ie Sky Sports 1. You could see the players faces, and those of the crowd. Then, we are "given" digital, They said the picture would be better, so they crammed upto 7 channels down 8mhz of bandwidth. This resulted in............... wait for it......... crap pictures that lacked definition. Ahhh they say you need HD TV!!! But pay us more money, and go to our sponsers/partners and buy an HD TV, there now you have good pictures!!!!

I've been had, Sky, NTL/TW greatest con trick ever!!!!!!!

I think you've got a very good point there! Although having seen some HD broadcasts, the quality is much better than ye olde analogue!

Quote:

Originally Posted by Wicked_and_Crazy

You cant compare analogue and digital in terms of bandwidth

No, but your average punter doesn't give a monkey's about bandwidth and digits - they care about the picture quality.