Moire patterns while watching digital broadcasts - maybe a question for Amir

[Orb]

If I see Moire patterns with some television programmes from the digital broadcast (satellite Sky here in UK) is this likely to be the programme, the Sky receiver, Pioneer Plasma TV, or a combination of all?
The type of pattern I am talking about is the one where it looks like very subtle banding-wave affecting say a solid wall/lighting effect against it.

I assume it is Moire pattern, but I do not see it for all programmes so makes me think it is not TV or box related but possibly channel-programme, although I do wonder if some digital settings could be aggravating this.
Edit:
I should had mentioned I assume it is possible this is being exacerbated with interaction of video compression/converted to 1080p, but this is something I cannot check.

Cheers
Orb

 

[amirm]

Moire is not a problem with video so I wonder if you are seeing what we call banding/posterization. Here is an example of it:

If so, it has multiple causes. It can be created by:

1. When the content is produced. When going to higher resolution to lower, this has to be done with dither. Unfortunately even "professionals" working on movies don't know this and create banding right in the source which cannot be eliminated after the fact.

2. Too much compression. Video compression relies on reduces the effective resolution of each video block. When pushed hard, you can see the reduced resolution in smooth graduated video images such as the sky.

3. The display. This is a pretty routine problem and the cause can be very hard to investigate as it can range from firmware error, to signal processing mistakes and flat out limited resolution of the display such as cheap LCD monitors.

If the problem is display independent, then it is either #1 or #2. Googling for user feedback on said content with phrases I mention often reveals other reports of the same problem if it is there.

 

[Orb]

Thanks Amir.
Ah yeah your right about it being mostly posterization-banding, but there is also moire-alias effect happening as well that is subtly different (this can also happen with video compression/transfer from film/etc).
But yeah as you say a lot of it is actually posterization-banding rather than moire.

So as I thought, not really anything that can be done, what about resolution size changes say if transmitted at 720p at upsampled to 1080, or even content that is not HD that is upsampled; anything to help alleviate this?
We have a lot of content that is not transmitted even as HD.
Just to say this is the BBC Technical Standards for Delivery of Television Programmes for General Picture Quality (sound is separated):

There must be no noticeable spurious signals or artefacts e.g. streaking, ringing, smear, echoes, overshoots moiré, hum, cross-talk etc

So will pay attention to BBC broadcasts, although usually I am pretty sure I do not see any problems nor posterization with their programmes unlike some other channels.

Thanks
Orb

 

[amirm]

If your TV supports playing still images through memory cards or otherwise, you can download smooth gray or color images and see what it does. If it has no posterization, then it rules out the display for the most part. Create the stills at the resolution of the display so that there is no resizing/resampling. Without detective work like this, it is hard to know where the problem might be.

Scaling does not frequently generate posterization so that would not be the first place I would look. That said, if you can change the settings in the settop box so that it outputs the native resolution of the source and letting the TV do the scaling, that would give you another clue as to potential issues.

Does SKY have its own STBs or is there an open market for third-party products?

 

[Orb]

Sky annoyingly is a proprietary solution, which is bloody annoying because it seems they are pushing too much functionality for the older boxes to handle (causes delayed response when going into the programme manager-list when it is about to change - say O'clock and 30 minutes past as that is when majority of channels switch to a new programme) and causing major delay response, watching a programme it is not noticeable only when trying commands like going into programme list,bring up information on current programme,etc.
And they charge an eye watering amount for their boxes sigh.
It is an issue that royally annoys a lot of their customers.

I will have a look and set the box to native, the TV is getting on a bit loooong in the tooth being Pioneer PDP-428XD but should do ok?
Yeah I am a slacker with my TV technology
Us Brits can be rather slow staying up on such things lol.
Cheers
Orb

 

[amirm]

The Pio should have good scalar. Just the same, be sure to set it to 1:1, or dot-by-dot or whatever it is called where it doesn't do any overscan.

As to being behind, for the longest time you were ahead of us with Teletext, PAL, etc. Only when HDTV came that for some reason Europe did not take seriously.

The situation in US for the walled garden providers is the same. With Comcast for example, you either get ancient boxes that struggle beyond any reasonable measure to do anything as they are 15 year old technology. I got the latest one (X1 from Comcast) and despite having been in the market for 1 to 2 years, is full of bugs. The simplest thing of displaying the Guide, causes it to display text on top of text, have boxes with nothing in them, screen savers that get stuck in that mode forever, etc. It is remarkable the power near-monopoly has in enabling mediocracy.

 

[Orb]

Thanks Amir for the suggestion.
Wow I guess Sky follows the trend then with their boxes
Cheers
Orb