NTL Digital Video Compression

[rdhw]

Originally Posted by simpsonsFAN

the sky premium channels are received by ntl in a totaly uncompressed format (270Mbits/second SDI video), and are then encoded at a bitrate that is higher than the other channels, you achally get a better (bitrate) picture on the sky premium channels on NTL, than you would do with sky.

Is there any way that the consumer can ascertain the bitrate of the channel being watched, on either Sky or NTL?

[SMHarman]

Originally Posted by arcamalpha2004

And I would agree

But some people seem to think that the picture is the same picture you eventually get whether you have NTL or SKY, I have had NTL and have SKY now, and can see your explanation as a good one.

I find the picture quality from my (thier) Pace 4000s to be very good.

Originally Posted by SMHarman

I find the picture quality from my (thier) Pace 4000s to be very good.

And that is ok, a lot of people may find a particular brand of hifi equipment to be very good, but equally a lot may not.
In my experience I have found sky plus picture quality to be better to that I had with NTL, the reason for this could be the design of the two boxes, better components used by sky in their boxes could be the reason, it is the only reason I can think of, because the NTL stb had been properly installed, the cables I use are the same cables, the only difference seems to be the actual boxes themselves.

[simpsonsFAN]

Originally Posted by rdhw

Is there any way that the consumer can ascertain the bitrate of the channel being watched, on either Sky or NTL?

Its possible to find out for sky using a DVB-S tuner card and decent spec PC, but for cable... well... I could tell you how to find the bitrates for cable... but then id have to kill you

-Chris

[Lew]

Originally Posted by SMHarman

I find the picture quality from my (thier) Pace 4000s to be very good.

The same can't always be said for the 4010 boxes, unfortunately. One some channels (IIRC it's those channels who use non-standard resolutions) the 4010 boxes have faint vertical lines on the picture, mostly noticeable on dark scenes.

Here's a mockup I made for an eariler thread that shows what I'm talking about (although the lines aren't quite so severe in reality).

[simpsonsFAN]

Originally Posted by Lew

The same can't always be said for the 4010 boxes, unfortunately. One some channels the 4010 boxes have faint vertical lines on the picture, mostly noticeable on dark scenes.

No, thats not a known problem, my 4010 is working fine and doesnt suffer that issue. Your box is clearly faulty and I would contact them to arrange a replacement.

Originally Posted by Lew

(IIRC it's those channels who use non-standard resolutions)

Since when has sky sports used non-standard resolutions?

-Chris

[Lew]

Originally Posted by simpsonsFAN

No, thats not a known problem, my 4010 is working fine and doesnt suffer that issue.

Strange, this is what I was told by an NTL person at another forum:

Incidentally, I've seen your post on CableForum about vertical lines on the screen. It's a problem we are aware of. It also happens on the Pace 4000 and Samsung boxes.

I know it's one of the those faults that you don't initially notice, but when you do it's really annoying. We don't currently have a solution other than requesting a box swap to a 4001

And I can confirm that it also happens on my brother's Samsung and my friend's 4010 box.

Your box is clearly faulty and I would contact them to arrange a replacement.

If the only option is to go back to a 4001 box then no thanks.

Since when has sky sports used non-standard resolutions?

-Chris

They don't. That picture is a mockup. It just happens that I already had a screengrab of Sky Sports handy and I didn't want to have to boot up my PC just to grab another one. Channels that I have seen this problem on include the ITV channels, Bravo and NASN.

[simpsonsFAN]

Originally Posted by Lew

And I can confirm that it also happens on my brother's Samsung and my friend's 4010 box.

If this problem was affecting every ntl customour with a pace 4xxx series box (apart from the 4001) or samsung box and was annoying as you say, then im pretty certain that ntl wouldent have many customours left!

Originally Posted by Lew

If the only option is to go back to a 4001 box then no thanks.

Its not the only option because I have a 4010 and have *never* seen this issue. I would think that a low quality scart lead, problem with your TV or dud box is most likely the case here.
-Chris

[Chrysalis]

Hard for me to comment as I have only had sky digi once and was about 4 years ago and have seen it the odd few times at friends/family. Each time I seen it the picture has looked fine enough for me to not notice anything. Ntl I have analogue which I guess doesnt have the problem so I cant comment on that.

[sollp]

I have Sky myself, very good picture, have visited many NTL customers house who have digital STB and the picture can vary depending on the TV they have. Both NTL and Sky have good picture quality, and like i have said the picture whether it be Sky or NTL will vary depending on the TV being used. This as i have said is after seeing many different Tv's and the picture quality whether on Sky or NTL.

So it depends on what you mean by the quality of the picture, obviously if your talking analogue, "is it a clear picture or grainy picture", with digital the bit rate will affect the data transfer to the STB, so are you talking about the picture pixelating freezing ect. This will happen both on Sky as well as NTL depending on various factors for example, the installation, quality of the STB ect. So by finding out the bit rate will you assume one is better than the other because it has a higher bit rate without really knowing why.

[ntl.wotcha]

One comment I would make. If it is the case that Sky premium content is delivered uncompressed and compressed by NTL, there is a huge difference between Sky One and Sky Two. The former is a good quality picture but the latter is quite obviously pixelated. Most annoying.

[simpsonsFAN]

Originally Posted by ntl.wotcha

One comment I would make. If it is the case that Sky premium content is delivered uncompressed and compressed by NTL, there is a huge difference between Sky One and Sky Two. The former is a good quality picture but the latter is quite obviously pixelated. Most annoying.

Interesting. That sortof confirms what I was saying, because Sky one is encoded by ntl themselfs at a higher bitrate, but Sky two is turned around at MPEG level from sky digital and is the same as would be recived with a sky satellite reciver.

Im surprised that it makes that so much difference that you can visably notice the different levels of compression between the two channels. Still, it could be worse, if you had sky then your sky one would be at the same low bitrate as sky two

-Chris

[alane123]

After having Sky for years and now NLT and Freeview for the last year, I am pretty used to Digital TV and I can honestly say that with NTL, the picture and sound quality, on a lot of the channels, has decreased in the last month or 2. I dont know who encodes their channels but there really is something going on.

QVC is a prime example the picture is terrible. Funny how this seems to have started roundabout when the recent new channels were added.

Also, every now and then the screen goes black as the signal goes out of synch and it needs to catch up or whatever it does.

I still have Sky for the free to air channels and I end up watching them, or even Freeview, as the picture and sound is far better.

What is going on?

[King Of Fools]

Originally Posted by alane123

QVC is a prime example the picture is terrible. Funny how this seems to have started roundabout when the recent new channels were added.

Also, every now and then the screen goes black as the signal goes out of synch and it needs to catch up or whatever it does.

That sounds more like your signal level has fallen to your STB than a reduction in bandwidth.

Do NTL charge channels based on how high a bitrate they use?

It would make sense to want more money from ITV 1 if they are using twice as much bandwidth as, say, UK TV Repeats-That-Were-Crap-First-Time-Round 3 +1.