Whenever i watch moving sport especially football I experience much poorer pictu
Brian Butterworth published on UK Free TV What you are seeing is one of the two problems that are well know about the "MPEG-2" system that is used to encode digital TV.
Because of the way the system works, horizontal movement across a crowd requires a disproportionate large amount of data to encode.
Because the bandwidth on Freeview is so limited, and as most broadcasters have decided to have more channels rather than better quality pictures, on most channels the bandwidth is so limited that the effect you see, a blurry mass of blocks is visible.
The sceptical will say that this is simply an excuse to sell you HDTV equipment and channel packages.
The other problem you will see is when strobe effects are used - this will often look like very large black and white boxes.
If these effects trouble you, do not go out and buy yourself a massive TV as they will be simply much clearer to you.
Tuesday, 6 June 2017
nicholas: Sorry, but I dont think any of that (including the moon landing thing) makes any sense.
Yes, VCR's used Macrovision to stop the copying of commercial tapes, but there is a simple reason why copying an analogue tape produces a poorer copy - its an analogue copy!
And the idea that manufacturers would deliberately make a poor SD TV to sell HD made no sense even 10-12 years ago - the last CRT TV was sold in the UK 11 years ago. They have all been HD since then. There is one very simply reason why you see 'noise' or a VHS signal etc on an analogue input compared with a HD digital source - the HD ones is better!
And why would this strange 'noise' continue with plasma TV's, DVD recorders, etc, which are no longer even made? And I have no idea what an 'lcd reciver' even is. 'SD camera?'
And why would people bother now? 80% of TV's are now 4k - so making a SD signal look especially bad is an utterly pointless activity.
'Digital blocks' are not noise - they are simply what happens when a digital signal isn't being processed properly.
The bottom line is that you've come up with a theory which made no sense in the first place, to explain things which are the natural results of an analogue or digital system. Your seeing things which are not there. And then coming up with an elaborate 'conspiracy' to explain it.
If your watching an analogue SD sources, it will not have as much data as a digital SD sources. An HD source has yet more data, and therefore looks better. Thats it.
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nicholas4:09 PM
ok,MIKE,whats the point,you've rejected anything i've said,if you dont want to try to understand,what can i say,its nothing to do with macrovision,etc,LCD tv abound,you've changed everything i've said,this is why the press is dying on its feet,too many witchunts against the local population and yr copy is typical of political correctness,i once made a complaint to BBc about hitting tube tv's with a hammer,i know about but got a pc responce about it ,its fine ,etc,i've broken tubes and had to get out of the way when the glass broke,its chased me out of the garage.Anybody hitting a tube will get the full force of glass coming their way,would cut you to pieces,if you want to be pc,then there's nothing more i can say.n...........
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nicholas4:14 PM
Mike,its pointless but its a money thing,nothing else,the next version is better than the last,tv's dont rust like cars and its an attempt to keep the money rolling,after all,the md does want the latest version of a private yacht ,etc,its Money,to keep it flowing,its MONEY<MONEY,nothing else...............You must buy the latest version cause we need yr money.n...........
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Wednesday, 7 June 2017
MikeP
10:24 AM
10:24 AM
Nicholas:
I'm afraid you are the one who has got it wrong.
Further, a CRT implodes as there is a vacumm inside. When the glass is broken it flies inwards first and then bounces off the other pieces of glass from the opposite side of the tube before expanding outwards rapidly. I was involved at Philips in the sixties in carrying out tests to develop the 'rim band' tubes to try preventing the face glass, which is thicker than the rest, from cracking and hence being a hazard when the implodes.
Please take note of what professionals are saying. Your arguments are technically incorrect.
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nicholas6:07 PM
MIKE,i go by experience,some will implode,some will explode,you will not know until the moment,no matter what,being next to a tv tube whether it implodes/explodes,isn't the place to be,you want to remain top dog,what more can i say.I am sure you didn't put yourself in the firing line when you tested the crt.No one in their right mind would hit a crt with any hammer,implode/explode,the glass is going somewhere,you are flesh,it doesn't mix with flying glass............n
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Thursday, 8 June 2017
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nicholas2:22 AM
mike,i rest my peace,you know what LCD screens are,i'm a thorn in yr side,n..
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M-B9:40 AM
Nicholas, you are entirely wrong, on all levels! Firstly, no manufacturer in their right mind would include any circuit to create additional noise, secondly, if they wanted to do so, they would just create the noise digitally within the processing! I have yet to see you provide ANY evidence of this circuit you say exists - why dont you post a link to an actual circuit diagram? Then we could look at this 'circuit', but you havent even provided that much evidence! Come on, post the circuit.
The effects you describe are caused by only two things - 1- poor received signal quality, due to your antenna and system and its relation to the transmitter. 2- they are natural effects of the limited bandwidth of the SD channels, where bitrate is limited to allow for more services. Motion requires greater bitrate than what is available, and hence the encoded video is restricted. This is part of how the video coding works in MPEG-2 and how the broadcaster wishes to choose their bitrates. If there was any conspiracy to degrade SD, then it would be done from the encoding end before transmission. I work in transmission and can assure you this is not done, and all what you are describing are natural effects of limited bitrate available on the 16QAM 8k modulation used for SD. HD uses 256QAM 32k modulation and so can carry much greater bitrates, at the cost of lower resiliance to over the air degradation.
You are arguing your case with no valid evidence, against people who are experienced engineers in the television industry, ranging across all aspects from studio and post production, encoding and muxing, transmission, and consumer maintenance/repair, and antenna installers. And they are ALL telling you you are wrong.
Either post valid and convincing evidence (not just your warped opinion) or accept that you are wrong
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MikeP
10:38 AM
10:38 AM
Nicholas:
CRTs never explode! They always implode due to the vacuum inside. We took high speed cinema film of all our experiments at Philips and they ALL showed the tube imploding and none exploding. Simple physics really.
When we did the tests some of us were directly in front of the CRT being tested - but protected by a toughened glass screen and metal enclosure. So yes, we were in the firing line. The test involved the CRT being hit by a mandrel supported inside a test cabinet and being hit by a 5kg weight dropped from 35 feet above the cabinet.
You clearly do not understand the lengths TV manufacturers went took to ensure viewers were safe from any implosions of the CRT. The glass does expand outwards AFTER the implosion, as I stated earlier.
I totally concur with what M-B states.
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