So how do they 'process' the picture to give the 'film' effect?

Would they use 1080/25p to get the film effect?

Indeed, it's not an effect. it is film, or near enough (AFAIK strictly, film is 24fps).

Would this be the precise reason Rock & Chips was broadcast interlaced on HD and filmised on SD, do you think?

That, or a cock up. I'm sure it's possible to "filmise" something so well that no one would no the difference between the 50i>25p conversion and a native 25p shoot - maybe the makers of Rock and Chips didn't dare try, or submitted a lousy conversion and got caught?

There exist unfilmised versions of filmised things which get shown by accident sometimes. e.g. there's a batch of clips from "The Office" which got used in other shows which are just standard 50i - i.e. dubbed off for promotion before the filmic effect was added. There were occasional inserts into early series of "Coast" which were straight 50i (the rest of Coast was filmised - quite badly in places). Also when true or filmised 25p content gets re-timed in some NLEs, the motion compensation creates intermediate frames/fields making it look like smooth 50i again! You see this mistake in quite a few programmes (I remember Casualty, Casanova, and Judge John Deed but there must be others) when someone decides to speed a scene up a little.

Cheers,
David.

ok - so is the pq better on STVHD, ITV1 HD (Granada) or ITV1 HD (London) ?

I am very happy with the pq using London (X factor looks amazing). However I am not overly keen on the audio only being in stereo, when my amp will turn the non dolby audio on Granada (and STV?) into Prologic Matrix.

I'm happy to be corrected about the equipment used for 'The Apprentice'. Although I'm a bit confused to see that merely shooting progressive will result in a film effect.

But again, I'm always pleased to learn from the considerable expertise on this forum.

I thought most amps would downmix DD2.0 to pro-logic. Both mine do.

So does mine (although I think downmix is the wrong term) and unlike lpcm it's automatically selected.

Dolby prologic extracts any matrixed rear channel info (limited frequency) to provide two additional rear channels from the discrete front stereo information which is not affected so plays without modification.

You're probably right!!

25p (and 25p-in-50i, and 25p with each frame duplicated to give 50p) look stuttery like film.
Native 50p and 50i look smooth like video.

Cheers,
David.

On ITV1HD (London) nothing comes through the back speakers.

It is set to Martix. On ITV1 SD I get amazing surround sound!

How can I tune to ITV1 Granada to check out the difference without changing post code?

Thanks

Assuming it's a Humax box, goto manual tune and change the transponder to 10936 V 22000 5/6 and scan. ITV1-HD Granada has pcm sound (same as the SD channels).

To get back to Freesat mode the Menu will now have a Freesat/Non-Freesat mode entry

oh!

I only watched about a minute of upscaled ITV news but the PQ was much worse - lacked depth and the onscreen graphics had jagged edges (the W was a give give away). Changed back to London very quickly!!!

STV HD has much better upscaling than any of the ITV1 HDs, it is listed as 3855 on the same frequency as ITV1 HD Granada. Granada will have more detailed pictures unless there is fast/complex movement, when you'll get a bit more blocking.

So if I set to an Ediburgh post code do I get STV HD on 119?

Thanks Graham, I think you have Frame 1 marked the wrong way round, London should be Granada and vice versa, as expected the Granada version shows more detail in the metal decoration and the shirt collar. Frame 2 is not exactly matched, Frame 3 shows differences possibly down to a contrast boost/red colour cast in ITV1 HD vs STV HD as I also found below:

ITV1 HD London 1440x1080 vs STV HD 1920x1080 Coronation Street originally transmitted 25/11/10

ITV1 HD London CS 1 (png) vs STV HD CS 1 (png)
ITV1 HD London seems to have had a contrast boost/red colour cast over STV HD, which also seems to boost noise levels significantly.

ITV1 HD London CS 2 (png) vs STV HD CS 2 (png)
More detail in man's hair & shirt collar

ITV1 HD London CS 3 (png) vs STV HD CS 3 (png)
Slightly more detail in man's hair & shirt collar

ITV1 HD London CS 4 (png) vs STV HD CS 4 (png)
Slightly more detail in hair & clothing

ITV1 HD London CS 5 (png) vs STV HD CS 5 (png)
Noticeably more detail in woman's bangle, filing trays slightly more defined on STV HD

ITV1 HD London CS 6 (png) vs STV HD CS 6 (png)
More fine detail in woman's hair

ITV1 HD London CS 7 (png) vs STV HD CS 7 (png)
More detail on woman's hair, face, and skin, noticeably sharper necklace

ITV1 HD London CS 8 (png) vs STV HD CS 8 (png)
Noticeably more woollen detail in scarf, sharper jacket and zip, hair

ITV1 HD London CS 9 (png) vs STV HD CS 9 (png)
more detail in hair, eyebrows, stubble, collar, and jumper

ITV1 HD London CS 10 (png) vs STV HD CS 10 (png)
sharper detail in jacket, hair

ITV1 HD London CS 11 (png) vs STV HD CS 11 (png)
sharper hair, jackets, zips and more accurate rendition of metal mesh in paper tray in background


I wouldn't do that as it oftens shows different content to ITV1 HD, you can view in non freesat mode though.

Very likely

It's not easy to match frame for frame so yes it could easily be 1 frame out. Looked for a straight cut which has to be accurate but the short period for reasonable recording times made that difficult. The one fact that was obvious looking at individual frames while the camera was panning or there was movement within the frame that a single frame has liitle relation to the perceived picture quality.

Obviously there isn't much difference on out of focus or fast moving subjects, but in a lot of scenes, possibly the majority of the time, things are relatively still and in focus and the difference is noticeable.

Perhaps I will take another look tomorrow then. I only tried the news tonight on Granada and the pq was terrible compared to London.

hmmmm

Some of us are more disturbed by technical quality issues that occur during brisk movement than by what (in my view) are minor issues on fairly static scenes.

But it is difficult for me to attribute the movement issues to any particular cause, it's almost certainly a combination of different things. I'd willingly sacrifice some 'static' quality and spatial resolution to improve the often dreadful blurring and sometimes jerkyness that occurs during brisk movement. It seems to me that not only have we failed to improve these issues following the introduction of HD TV but they may now be more noticeable than before.

This is a major failing of the current 1080i HD TV system in my view, though i wouldn't presume to know how it can be solved as I don't know the (no doubt multiple) exact causes, except in broad terms as I've mentioned before.

jzee

Thanks for posting these stills comparing ITV London and STV. I guess the first point is that niether look very nice. The STV versions appear to have both more detail and less noise than the London ones. The noise on the London version is frankly awful by comparison. Surprisingly bad. My best guess is that at least a proportion of this is added noise because the STV pictures do look to have at least as much genuine detail as the London picture and I suspect a little more. I also notice that the vertical and horizontal edges look a lot better on the STV version. However the angled edges are better on the London picture. The dynamic performance of these two channels could be a very different story but to be frank, based on just these stills, if I had bought the ITV London upconverters I would not be best pleased.

You've said this before IIRC. There's nothing intrinsic in the system or the coding that causes what you describe. It's the STB doing something funny, or your TV, or maybe you're seeing low bitrate artefacts that I've never spotted.

At the bitrates (and with the specific encoders) that More 4 (SD!) uses, sometimes the encoders appear to combine fields (giving momentary jerky motion from a 50i source). At low bitrates, any encoding algorithm is going to introduce some softness (mostly MPEG-4) or mosquito noise (mostly MPEG-2) or blockiness (mostly MPEG-2) when complex images move unpredictably. But I've never seen anything that I'd describe as "dreadful blurring" other than that added intentionally at the point of filming or in post production.

Cheers,
David.

Isn't it just the fact it is interlaced? Presumably with 720p/1080p you'd get a lot less blurring with movement, but 1080p isn't going to happen anytime soon and UK looks unlikely to switch to 720p if you're desparate for some sports events you can get them in 720p on the German FTA HD channels on 19.2).


Is it not to do with ITV1 boosting the contrast too high, or have STV HD just reduced the red level, you could almost say STV HD has a slight blue cast?


Can you point out any images in particular where this is the case, I can't see it myself.


Do you mean upscalers? Coronation Street is actually in HD although STV HD does indeed appear to have better upscalers, although it is a bit of a mystery as the upscaling of cartoons on ITV1 Granada is better than that of London so it appears not all content on ITV1 HD Granada is handled by the same people as ITV1 HD London.

There is a significant difference here; too much for just a change in contrast. There is noise on the London image that is just not there on the STV one. The edges are really rather ragged on the verticals in the London version.

I am flumoxed. I had understood that you were presenting these as upconverted - my fault. The quality looks really rather poor for HD don't you think? The noise on the London picture looks rather analogue. If I were to take a guess I would say that these, well particularly the London one, looks like it was converted to analogue in the receiving process. Like it had been decoded in one box and then sent analogue to another to be captured but if that were true I am sure you would have said. It could just all be filmed in low light but that would not explain how STV got less noise and more detail. I am confused.


No problem. On the first picture there is a cart in front of the staircase banisters. I think it might be ceramic or wood. Its wheel has spokes painted on. Look at the diagonal spokes really closely. The STV versions are a mess. The London ones slightly more coherent. It is subtle. We can guess that these are straight lines in the original scene. This is the one area where the London picture seems superior.



Strictly an upscaler is used in or with a display. If you are processing a signal, normally from SD to HD, within a signal path then it is an upconverter. I do not think the terminology is really important though.

I hope that is of some use.