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HD UpScalers
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LCDMAN
22-10-2007
Up/down scaling is optional extra function and only between HD-SDI and SD-SDI by the look of it. It's not the sort of kit used pre-transmission, but for OB & sat uplink use or IP TV type applications to encode signals for multicast/streaming.

H.264 encoding does not include scaling! It's an encoding standard and has nothing - repeat NOTHING - to do with scaling - just believe baby!


LCDMAN........The man with no sig!
TommyW
22-10-2007
Originally Posted by LCDMAN:
“Up/down scaling is optional extra function and only between HD-SDI and SD-SDI by the look of it. It's not the sort of kit used pre-transmission, but for OB & sat uplink use or IP TV type applications to encode signals for multicast/streaming.

H.264 encoding does not include scaling! It's an encoding standard and has nothing - repeat NOTHING - to do with scaling - just believe baby!


LCDMAN........The man with no sig!”

If it's an optional extra then it could be included in the encoder package.

I have no idea what equipment Sky use, but who's to say they haven't got a similar setup, H.264 encoders with optional extras.

Whatever way you look at it, it's an 'encoder' that can have the ability to upscale in real time and encode to HD H.264.
Jarrak
22-10-2007
Originally Posted by TommyW:
“
I have no idea what equipment Sky use, but who's to say they haven't got a similar setup, H.264 encoders with optional extras.
”




Tandberg supply the encoding hardware to SKY although I have no idea if they also supply the scaling suite which SKY use to broadcast SD source material on their HD channels.
I would be surprised if it wasn't an all in one solution though after all simple PC based video encoders (hardware and software) provide the ability to manipulate the resolution and other factors during processing.
LCDMAN
22-10-2007
Quote:
“If it's an optional extra then it could be included in the encoder package”

I could light a fart and fly to the moon - doesn't mean I do though.

I'm leaving this thread now as your "could", "might" and "maybe" circular arguments are doing my head in. H.264 encoding does not include scaling - you might get a bit of kit to do both, but the encoding has nothing to do with scaling and they do not go together.


LCDMAN........The man with no sig!
TommyW
22-10-2007
Originally Posted by Jarrak:
“Tandberg supply the encoding hardware to SKY although I have no idea if they also supply the scaling suite which SKY use to broadcast SD source material on their HD channels.
I would be surprised if it wasn't an all in one solution though after all simple PC based video encoders (hardware and software) provide the ability to manipulate the resolution and other factors during processing.”

Cheers for that Jarrak.

This would also be my way of thinking. To me it's the most logical.
JimRockford
04-11-2007
Originally Posted by jase1:
“So it does guess then!

"Interpolation" = "guesswork", by definition.

It can be a very good guess, but it is a guess nonetheless.
”

To be fair it's not a guess, it's already got loads of picture to work with.
Nigel Goodwin
05-11-2007
Originally Posted by JimRockford:
“To be fair it's not a guess, it's already got loads of picture to work with.”

But it's trying to produce fine detail, which isn't there - so it can only be a guess. In any case, the results of Broadcasters upscaling, DVD upscaling, or TV upscaling, all bear no resemblance at all to an HD picture.
jwball
05-11-2007
You should remember that "experts" are always right!
They never make mistakes
bobcar
05-11-2007
Originally Posted by Nigel Goodwin:
“But it's trying to produce fine detail, which isn't there - so it can only be a guess. In any case, the results of Broadcasters upscaling, DVD upscaling, or TV upscaling, all bear no resemblance at all to an HD picture.”

The key is information content so it would be possible to upscale an SD picture that had low compression (high information content) and get a better picture than with HD that was highly compressed. The point is though that HD always has more information than SD in any real source available for home viewing.
Nigel Goodwin
05-11-2007
Originally Posted by bobcar:
“The key is information content so it would be possible to upscale an SD picture that had low compression (high information content) and get a better picture than with HD that was highly compressed. The point is though that HD always has more information than SD in any real source available for home viewing.”

I don't care if the SD source is totally uncompressed, it still hasn't got the definition required for HD - and you can't accurately recreate something that has never existed. At best you can extrapolate and 'guess' what might be there, but it's unlikely to have much relation to reality.

And like I said before, I've yet to see (or even hear) of any upscaling that produces anything remotely resembling HD.
bobcar
05-11-2007
Originally Posted by Nigel Goodwin:
“I don't care if the SD source is totally uncompressed, it still hasn't got the definition required for HD - and you can't accurately recreate something that has never existed. At best you can extrapolate and 'guess' what might be there, but it's unlikely to have much relation to reality.”

But it does exist, there is information there. To give a simple example any straight line can be continued "in the gaps" and will in all probability be what was there without a missing line. By contrast a a highly compressed HD image may well be really fuzzy about where the line goes. You would look at the upscaled image and see something closer to reality than the HD one - the compressed HD image is a bigger guess than the uncompressed upscaled one.
Quote:
“And like I said before, I've yet to see (or even hear) of any upscaling that produces anything remotely resembling HD.”

Because the information content of SD sources is far lower than that of HD sources. As you said you can't put back something that really wasn't there.
Nigel Goodwin
05-11-2007
Originally Posted by bobcar:
“Because the information content of SD sources is far lower than that of HD sources. As you said you can't put back something that really wasn't there.”

So does that mean you agree with me that upscaling is crap, and nothing like HD? - rather sounds like it?.
bobcar
06-11-2007
Originally Posted by Nigel Goodwin:
“So does that mean you agree with me that upscaling is crap, and nothing like HD? - rather sounds like it?.”

Although some upscalers (especially the really expensive ones) can do a decent job it's still not HD (nothing like it for an upscaling DVD player). I wouldn't say they are all crap though.
Chorley Matt
06-11-2007
Originally Posted by LCDMAN:
“But of course there are specialist image scalers/processors around which DO turn SD signals to HD and beyond. Expect to pay £2k+ though, which only makes them suitable for expensive home cinema installations. Only useful if the end display can accept its native resolution without doing any scaling itself.

{before Nigel argues with me, I should know - I design them! see some of my products here, www.calibreuk.com, from £2k for home theatre use to £45k for professional digital cinema processors}”

If the original information is not there, no matter what terms are used to describe the process, it is still guesswork. Yes, there are more technically proficient (therefore more accurate and generally more expensive) ways of doing this, but it still involves an element of guesswork. If the incoming image is, to use your example 576i, you have a starting point of just 288 lines per frame. No matter how good the technology used is, no matter how many factors are taken into consideration, from such a low definition starting point you will never recreate a 100% accurate 1080p image. You simply cannot guarantee to replicate something that was not part of the original information. I've no doubt it will be vastly superior to a cheapo upscaled image but it will never be true HD.

By the way, you've got "Distribution" spelt incorrectly on your website under the grey "Our Products" section to the left of the homepage - the "r" is missing. No matter how I were to process the image, I would never recreate that missing letter!
bobcar
06-11-2007
Originally Posted by Chorley Matt:
“By the way, you've got "Distribution" spelt incorrectly on your website under the grey "Our Products" section to the left of the homepage - the "r" is missing. No matter how I were to process the image, I would never recreate that missing letter! ”

Yes you could if your image processing included a spelling checker. It would be a guess that the 'r' should be there but would probably produce the correct result. Imagine a more reasonable situation where the 'r' has gaps along it's length, the image processing can fill in the gaps because "it's an 'r' with gaps in" and the result would be the same as an HD picture. Of course it may be that the gaps were meant to be there but in most cases the result would be correct.

There's a limit to what you can do and I agree that the result of upscaling is not HD but there is a lot that can be done especially if the SD message has a high information content (not heavily compressed).

It's certainly the case though that anyone who buys an upscaling DVD player is in for a bit of a shock if they think that gives them HD or anything like it.
JimRockford
06-11-2007
Originally Posted by Nigel Goodwin:
“But it's trying to produce fine detail, which isn't there - so it can only be a guess. In any case, the results of Broadcasters upscaling, DVD upscaling, or TV upscaling, all bear no resemblance at all to an HD picture.”


No resemblance at all? I think that's a tad unfair. Of course the quality will vary from source to source, and the size of screen you show it on will be a factor too, but broadcast scaling is very very good. I doubt the layman could tell the difference under certain conditions. There's a lot of scaling technology about and this 'guesswork' is actually a lot more sophisticated than it sounds.

Originally Posted by bobcar:
“
It's certainly the case though that anyone who buys an upscaling DVD player is in for a bit of a shock if they think that gives them HD or anything like it.”

If they buy something that costs £80 then yes they would be. If they buy something costing £500 or more then no, they will be very pleased.
LCDMAN
07-11-2007
Quote:
“If the original information is not there, no matter what terms are used to describe the process, it is still guesswork. Yes, there are more technically proficient (therefore more accurate and generally more expensive) ways of doing this, but it still involves an element of guesswork. If the incoming image is, to use your example 576i, you have a starting point of just 288 lines per frame. No matter how good the technology used is, no matter how many factors are taken into consideration, from such a low definition starting point you will never recreate a 100% accurate 1080p image. You simply cannot guarantee to replicate something that was not part of the original information. I've no doubt it will be vastly superior to a cheapo upscaled image but it will never be true HD.”

I know I said I was leaving this thread to you lot, but I can't help myself.

Just because it is a 576i signal NOW, doesn't mean that's all it ever was. That might be the starting point for this process, but it isn't the starting point for all the processes the signal has undergone. If it was originally shot on film then the information content at that point was much higher than 288 lines per frame and it's that information that we mathematically recreate by interpolation - in effect reversing the processes that the signal has been subjected to. It WAS part of the ORIGINAL information and can therefore be recovered, even though it might not be evident in THIS VERSION of the information.

If you still want to call it a guess, then it's a good enough, accurate, repeatable (ie the same information undoing the same process yields the same result every time), enough guess for you not to notice the difference. If any of you find yourself around Bradford then pm me and I'll happily set you the "HD or not-HD source?" challenge. (always assuming you have half decent eyesight and recognise a barn door )

It's the same with MPEG encoding noise, that is an entirely reversable process providing that the process was applied evenly and consistently to the signal (and even 99.9% sometimes when it wasn't).



LCDMAN.........really is leaving this thread now, honest!
Last edited by LCDMAN : 07-11-2007 at 11:40
Nigel Goodwin
07-11-2007
Originally Posted by JimRockford:
“No resemblance at all? I think that's a tad unfair. Of course the quality will vary from source to source, and the size of screen you show it on will be a factor too, but broadcast scaling is very very good. I doubt the layman could tell the difference under certain conditions.
”

Would those 'certain conditions' be a layman with an guide dog and a white stick?

Perhaps you would care to give some examples of broadcast scaling which look any different than SD? - I've never seen any, the upscaled SD on the HD channels looks slightly better than the SD channels, but I would suggest that's because it's using four times the bandwidth, not because of any broadcast upscaling.

Quote:
“
There's a lot of scaling technology about and this 'guesswork' is actually a lot more sophisticated than it sounds.”

I don't doubt it's clever, and the more expensive it is, the more clever it needs to be - but it still bears no resemblance to HD?.

HDMI and upscaling are the current 'buzzwords', and loads of people (including on here!) are being conned into thinking that upscaling produces HD, and it doesn't.
LCDMAN
07-11-2007
Quote:
“Perhaps you would care to give some examples of broadcast scaling which look any different than SD? - I've never seen any, the upscaled SD on the HD channels looks slightly better than the SD channels, but I would suggest that's because it's using four times the bandwidth, not because of any broadcast upscaling.”

At last, something we agree on!

The fact that the signal has been through all the processes necessary to broadcast it means that it will look cr@p (IMO) - UNLESS you then do something to it to improve/recover it from all the processes it underwent - which Sky boxes don't do. Whether the source material was SD or HD, it all suffers from the processes it undergoes to be broadcast, so I agree - yes it looks cr@p! But not necessarily because of the conversion from SD to HD, rather because it has then been mucked around in order to be broadcast.

Give me an SD DVD player giving out 576i (so NOT upscaling), into one of our boxes and out to a 1080p native display vs HD-DVD (or Blu-Ray) at 1080p straight in to the display and you won't tell the difference.

Ar$e about with the signal even more in order to broadcast it and it will always appear different (worse?) to the direct one. As I said above, even HD, when broadcast, is compromised because of the constraints placed upon it by the transmission medium (but this is by no means unrecoverable).

To summarise my ramblings, any "improvement" SD might have by being scaled to HD before broadcast is undone by all the processing done to the signal to be able to broadcast it. What you really need to compare is the upscaled SD BEFORE it then gets mucked about for broadcasting. It's like washing your car, & polishing it then throwing a bucket of mud on it! You just undid all the good work.

Didn't the OP ask about upscaling DVD's - not broadcast stuff


LCDMAN...............Lied about leaving this thread alone!
Nigel Goodwin
07-11-2007
Originally Posted by LCDMAN:
“At last, something we agree on!

The fact that the signal has been through all the processes necessary to broadcast it means that it will look cr@p (IMO) - UNLESS you then do something to it to improve/recover it from all the processes it underwent - which Sky boxes don't do. Whether the source material was SD or HD, it all suffers from the processes it undergoes to be broadcast, so I agree - yes it looks cr@p! But not necessarily because of the conversion from SD to HD, rather because it has then been mucked around in order to be broadcast.

Give me an SD DVD player giving out 576i (so NOT upscaling), into one of our boxes and out to a 1080p native display vs HD-DVD (or Blu-Ray) at 1080p straight in to the display and you won't tell the difference.

Ar$e about with the signal even more in order to broadcast it and it will always appear different (worse?) to the direct one. As I said above, even HD, when broadcast, is compromised because of the constraints placed upon it by the transmission medium (but this is by no means unrecoverable).

To summarise my ramblings, any "improvement" SD might have by being scaled to HD before broadcast is undone by all the processing done to the signal to be able to broadcast it. What you really need to compare is the upscaled SD BEFORE it then gets mucked about for broadcasting. It's like washing your car, & polishing it then throwing a bucket of mud on it! You just undid all the good work.
”

So your wonderful upscaler will produce as good a quality as an original HD source, yet if you broadcast the two signals the HD source remains HD and wonderful, yet your upscaled 'HD' returns to being SD and rubbish?.


Is it just me that finds a flaw in your reasoning there?.

Quote:
“

Didn't the OP ask about upscaling DVD's - not broadcast stuff
”

Shouldn't make any difference?, if the SD is truely converted to HD (which I don't believe) then it should travel through either medium just as HD does.

Quote:
“
LCDMAN...............Lied about leaving this thread alone!”

No problem, a little lie adds interest!
LCDMAN
07-11-2007
Quote:
“So your wonderful upscaler will produce as good a quality as an original HD source, yet if you broadcast the two signals the HD source remains HD and wonderful, yet your upscaled 'HD' returns to being SD and rubbish?.”

No, I am saying both the upscaled SD and "true" HD suffer from being broadcast! Yes, even HD is not as good as it would be if NOT mucked about in order to be broadcast. Therefore you cannot be sure that what you have decided is a failure of the SD upscaling process isn't caused by the pre-broadcast processing! (Especially the encoding process) My argument is that if you don't do this further processing then you can't tell the difference, and I'm happy to prove that.

If you are basing your opinion of SD upscaling success solely on what Sky broadcast then remember that what you are seeing has been subjected to many other processes in order to broadcast it, which affect the end result (badly). In this respect I agree with you, SD converted to HD and broadcast looks less than optimal (so does HD), but for different reasons - you say it's because of the upscaling, I say it's because it's been further processed in order to be broadcast!


Quote:
“Shouldn't make any difference?, if the SD is truely converted to HD (which I don't believe) then it should travel through either medium just as HD does.”

See above; being broadcast makes all the difference!


As I said earlier, come see what can be done when it's done properly (NOT compromised by being further processed for broadcast) and see if you can tell the difference then.

It's worth a look here too;

http://www.teranex.com/

Anyway, enough of this - it's too deep for DS, come over here and argue with the professionals;

http://www.avsforum.com/avs-vb/forumdisplay.php?f=37

I'll hold yer coat

LCDMAN....Happy to have visitors!
Gilson
07-11-2007
Originally Posted by LCDMAN:
“See above; being broadcast makes all the difference!”

Are we talking about analog or DTT here? If the latter what progs and bitrates?(very)
GDK
08-11-2007
I just don't believe LCDMAN. You can't get back something you've already thrown away!

I agree that when the original source that was 24fps film, there are ways to get more from an SD transfer than many would expect, because of the progressive nature of the original and what that means for the actual frames and fields. But it appears you're basically saying you can get back something that's already lost.

If what you're saying is true (cleverly upscaled SD can look as good as original HD) then why do the studios go to the trouble of re-scanning original film material at higher definitions to produce HD masters, and not just "cleverly upscale" the broadcast quality SD master tapes?

Are you saying that, for example, Paramount could generate true HD quality from the SD video masters of Star Trek: The Next Generation? That it was a waste of effort re-scanning all the old original Star Trek episodes from the original film stock to make it into HD? Why not just take the masters for current DVDs and cleverly upscale them to make Blu Ray or HD-DVD disks?
Nigel Goodwin
08-11-2007
Originally Posted by LCDMAN:
“If you are basing your opinion of SD upscaling success solely on what Sky broadcast then remember that what you are seeing has been subjected to many other processes in order to broadcast it, which affect the end result (badly). In this respect I agree with you, SD converted to HD and broadcast looks less than optimal (so does HD), but for different reasons - you say it's because of the upscaling, I say it's because it's been further processed in order to be broadcast!”

Except broadcast HD looks HD and absolutely stunning, yet broadcast upscaled SD looks rubbish and just like an SD picture.

As presumably the same processes are used to broadcast both?, I don't see how you can claim that before broadcast the upscaled SD is just as good?. If it was 'just as good' it would broadcast OK, because it wouldn't be any different.
JimRockford
11-11-2007
Originally Posted by GDK:
“
Are you saying that, for example, Paramount could generate true HD quality from the SD video masters of Star Trek: The Next Generation?”

Actually, they are experimenting with this very thing at the moment. Because the Next Generation only exists on tapes. It was made in an era where they transfered the film to tape and post produced the show digitally, before archiving it off onto Betacam. There are no film masters of the completed series, unlike the original Star Trek. The days will come eventually when they release upscaled SD stuff on Blu-ray or HD-DVD, (stuff that doesn't exist on film) that has been professionally upscaled and people will be surprised at the quality.

I don't think anybody is arguing that upscaled SD is a 1:1 match for true HD, it's going to lack some fine detail. But anybody that dismisses what *can* be achieved through professional upscaling (and you can achieve at least halfway house with good material) is frankly misinformed. Also, there's a lot more to picture quality than just resolution.

Oh and SKY HD is not a good way to judge things.
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