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Home Entertainment Blog Archive

Brought to you by your friendly, opinionated, Home Entertainment and Technology writer, Stephen Dawson

Here I report, discuss, whinge or argue on matters related to high fidelity, home entertainment equipment and the discs and signals that feed them. Since this Blog is hand-coded (I like TextPad), there are no comments facilities. But feel free to email me at scdawson [at] hifi-writer.com. I will try to respond, either personally or by posting here emails I consider of interest. I shall assume that emails sent to me here can be freely posted by me unless you state otherwise.

This archive is for an uncertain period commencing Thursday, 11 March February 2004

More on 'judder' - Tuesday, 23 March 2004, 10:48 pm

The concept of picture 'judder', to which I referred two posts down, is very easy to show in a demonstration, but rather harder to explain in words. I've already received an email from a person along these lines. So rather than re-inventing the wheel, here's a section of a review of a Philips TV I wrote in early 2000. The TV's main innovation was to actually eliminate judder, so the review (I think, anyway) explains the issue rather well.

But I've saved the best for last: what it is that makes A Bug's Life so different.

If you have this DVD, I'd suggest you stop reading right now and go to your TV. Choose the full screen side of the DVD and start the movie. Right near the start there is a medium speed 'camera' pan up over some mud flats to the island upon which the starring ants reside. You will notice that the cracks in the mud seem to judder down your screen, jumping by discrete intervals with each frame of the movie. Sorry, but after the Philips demo of this, I've not been able to avoid seeing this myself, an effect of which I had previously been blissfully unaware, being so used to it.

The judder is not due to the PAL picture or TV representation, but to our own sense of perception being sensitive to a range of movement speeds that interfere with the 24 or 25 frames per second of film or PAL TV.

What I would like is for you to be able to watch this scene with the Philips TV under review. This has an option under its 'Picture' menu called 'Natural Motion'. Select this and watch the same scene. The motion is silkily smooth. No judder at all. Quite incredible.

How is this done?

First, some background. A TV makes moving pictures by showing in succession 25 pictures (frames) per second. Each of these is made up of two pictures, interleaved line by line, so 50 separate pictures (called fields) are shown per second. This is your standard TV. An increasing number of high-end TVs are 100 hertz units. To reduce irritating screen flicker, these play each frame twice, so you end up with 100 pictures per second.

Now good old 50 hertz TVs had wonderfully fuzzy screens. Most nice new 100 hertz TVs have wonderfully crisp displays, as does this Philips TV. But the sharp focus means that the judder, previously concealed by screen fuzziness, is revealed. Philips new technology, 'Digital Natural Motion', instead of repeating each frame twice as in a standard 100 hertz set, calculates each intermediate frame as a new one, based on the preceding and the following ones.

This makes A Bug's Life smooth. It works sideways as well, with one of the distant shots of the bikers in Easy Rider equally dropping all the judder (have a look around 19:12 into the movie).

This change is not subtle. But other effects are. First, a negative one. The processing seems to become a little confused when a sharply defined tan or black object moves across a diffuse green background, such as a person moving in front of foilage. This produces a subtle swirl around the edges of the foreground object, as though the air immediately around it is being heated, causing a lensing effect. An example of this is also in Easy Rider (see Dennis Hopper's coat at 31:17). This appears only very occasionally, and is subtle.

Another subtle effect, but a more significant one in the longer term, has ultimately left me ambivalent about this processing. In short it improves the clarity of the film, making the visual representation ever so smooth. At some points it is breathtaking. In Easy Rider closeup shots of the characters taken in outdoor settings look, well, too clean, as though taken in the studio.

Why should this be? Well, consider the processing. Every second displayed frame is an average of the one before it and the one after it. Each real frame is a copy of the film frame. Each of these has film grain (especially on the 16mm film used for this movie), randomly distributed so the grain is different in each shot. The averaging of the intermediate frames removes the grain, so half the time the picture you're watching is film-grain free. A welcome side effect is that DVDs telecined from poor quality prints, such as Blade Runner, lose a great many of the scratches and dust marring the film.

So why am I ambivalent? It isn't the heat-haze effect. It's the super clarity. Somehow it just seems too good.

Since then the technology has been improved and the 'halo' effect I referred to seems to have disappeared. Some Loewe TVs also use a similar system which also seems to work well. But they are still far from perfect. Sometimes they get quite confused with fine crosshatch patterns and dissolve the lot into a defocussed mess. But this seems to be rare now.

These days I don't recommend high-end Philips CRT TVs because they have a huge flaw: they do not allow you to switch off all this digital processing. Nice as it is to have it available, I like to be able to switch it off if it is causing problems, or if I just want to see the movie as it was originally made, rather than as the TV 'improves' it.

HD dilemmas - Tuesday, 23 March 2004, 10:23 pm

For the last entry I was using a VisionPlus DTV card to check out the new WIN high definition TV transmission. As of today I'm using a high definition (1080i) CRT-based RPTV and a HD set top box, and this reminds me of a problem we'll have with HDTV for a while yet.

The RPTV runs PAL TV at 100 hertz. But 576p, 720p and 1080i all kick it back to 50 hertz. The problem: it flickers at 50 hertz. This is inevitable in CRTs (unless they get ones that will run much, much faster) because during the design phase of the CRT, you have to choose the persistence of the phosphors. Too long and you don't get the benefit of 100 hertz. But because they don't persist for long, when the tube is running at 50 hertz you get flicker.

The answer is obvious: go for a digital display. Plasma or LCD or some form of projector. Except for one problem with these: none of these has the resolution to fully display 1080i HD, so they all have to scale this down to fit their native resolution.

Eventually their resolution will rise to meet the challenge, but for the time being if you want to watch 1080i high resolution TV, you have to choose between the 50 hertz flicker of CRT-based devices, or a loss of resolution from a digital display device.

WIN TV goes HD in Canberra - Friday, 19 March 2004, 10:18 am

Last night I went to the official opening of the new Bing Lee store in Fyshwick, Canberra. Nice store. I'll be writing about that for Appliance Retailer sometime today (if you're reading, James :-). There, one of the speech-makers disclosed that WIN TV (the regional version of Channel 9) had started high definition digital TV broadcasts that afternoon.

Checked it out today. Sure enough, it's now on. Kind of. Actually, it's only a loop of HD material (I think the same loop that Channel 9 used to use). But it is in 1080i and some of the detail is simply spectacular.

One interesting side effect, though, is increased 'judder'. That's nothing to do with WIN but with the 1080i. This shows 25 frames per second (50 interlaced fields, thus the 'i'). Because the image is sharper than standard definition, camera pans and the like resolve the movement of detail more clearly so the pans become less smooth as you see the finely detailed image in one position, then slightly displaced one 25th of a second later, and again a bit later, and so on.

This is less likely to be noticed on most movies (when they get around to putting actual program material on) because competent cinematographers balance their shutter speed/aperture to ensure a small amount of smearing during pans and significant subject motion and this irons out the judder. (For an example of this, watch the opening moments of A Bug's Life -- as the 'camera' pans up over the mud flat, the sharp edges of this clearly clunk down bit by bit. Yet throughout most of the movie, particular on the characters, the computer programmers have introduced an artificial 'camera smear' to avoid this during character movement. Freeze the picture during fast motion and you'll see this quite clearly.)

Anyway, for those in Canberra who have a high definition tuner and want access the new WIN HD service, you will need to adjust your digital TV receiver's settings. The easiest way is to note on what station you receive the SD version of WIN (UHF Channel 65 or 788.5MHz for Tuggeranong and Western Creek, VHF 11 or 219.5MHz for those with direct reception from Black Mountain Tower), go into the receiver's settings menu, select the 'manual' search option and key in the channel or frequency as appropriate, then hit search. The tuner will find two stations, entitled 'WIN TV Canberra' and 'WIN TV HD'. These are generally numbered 8 and 80 respectively.

If you would rather re-do the whole tuning, I strongly suggest that you find the 'Factory Reset' option first and use this to zap all the current settings. Then when you do the scan you won't double up on stations (some tuners don't handle this at all elegantly).

DVD Recording convergence, or LG goes quad - Thursday, 18 March 2004, 1:22 pm

For the last couple of years I've been arguing that the multitude of recordable DVD formats (DVD+R, DVD-R, DVD+RW, DVD-RW, DVD-RAM) do not threaten a repeat of the Beta/VHS wars of two decades ago. To put it simply, unlike the competing VCR formats, all recordable DVD formats fit into the same hole. All the rest is details.

LG DR4812W DVD recorder Previously my point has been partially proven by Sony's DVD recorders, the RDRGX3 ($AUS1,399) and the RDRGX7 ($AUS1,699), which support DVD-R, DVD-RW and DVD+RW, and the Toshiba D-R1 ($AUS1,499 -- DVD-R, DVD-RW, DVD-RAM), and any number of multi-format DVD burners for computers. But today a new consumer DVD recorder from LG Electronics has just lobbed into my office. The LG DR4812W supports four formats: DVD+R, DVD-R, DVD+RW and DVD-RW. By 'support', I mean it will record to all four of them. I haven't opened the box yet, so I don't know how well it does this, but this remains an impressive achievement. The price looks good too, at $999, and this includes a DV input which many entry level models don't have. Okay, I just got it out of the box and it looks a lot more attractive than my picture implies, with a mirrored lower half. One downside on facilities: the back panel video input is composite video only. There is S-Video, but this is only on the front panel, which leads to ugly cabling if you want to leave it permanently connected to a digital TV receiver for recording.

Come 20 May, LG's DR4922W will come out at $1,099. This one adds a slot for various flash memory cards.

Euro-NTSC - Thursday, 18 March 2004, 10:20 am

The other day my brother, who is somewhat of an Austria-phile, was pondering his collection of DVDs of the annual Vienna New Years Day concerts. As he says:

Each year it is released on a different label although the content is always sourced from ORF (the Austrian ABC).

1987 - Sony.
1989 - Deutsche Grammophon.
2000 - EMI.
2001 - Teldec.
2002 & 2003 - TDK.
2004 - Deutsche Grammophon.

The weird thing is that out of all of these DVDs both Deutsche Grammophon are in NTSC. The others have an NTSC version for the US and a PAL version for Europe. A quick check on Amazon.uk reveals all the DVDs released by Deutsche Grammophon are NTSC - but this is a German company??? Strange.

So why would Deutsche Grammophon do all its DVD releases in NTSC when it is a German company (Germany is not just a PAL nation, but the home of PAL). Here are a couple of possible explanations.

First, if a company wants to keep its inventory small by carrying just one format, yet sell in both Europe and the US, then it's wise to encode NTSC rather than PAL. The reason is that the majority of TVs sold in Europe (and Australia) over the last ten years will display both PAL and NTSC, while most TVs sold in the US will display NTSC, but not PAL.

Ordinarily I'd say that DG still ought to provide us PAL-people the best possible quality (ie. PAL), except for one thing. If DG used film rather than video to record, then the transfer to PAL involves a 4% speed increase and, consequently, a 4% pitch raise (the 24 frames per second of the film are simply transferred, one-to-one, to the 25 frames per second of PAL video). Since DG is primarily a classical music record label, pitch accuracy may well be higher on its list of priorities than video resolution, so perhaps they chose to go NTSC for the sake of the audio. It is possible to do film to PAL conversions while preserving the audio's pitch, but this can result in video that has the dual disadvantage of suffering from NTSC-like interlacing, without the redeeming feature of being effectively corrected by the enormous amount of equipment designed to minimise NTSC interlacing.

This argument doesn't apply, of course, if the thing was captured in either PAL or NTSC video in the first place.

Universal also stuffs up on 'anamorphic' label - Thursday, 11 March 2004, 9:53 am

I was whinging earlier (and here as well) about MGM releasing low cost Region 4 DVDs in non-anamorphic widescreen, while claiming on their boxes that they are actually '16:9' (ie. anamorphic) transfers. Now, it seems, Universal is up to the same old trick.

The offending title this time is the well-regarded 1998 Elmore Leonard/Steven Soderbergh crime thriller Out of Sight. In Australia this title was first distributed on Universal's behalf by Columbia TriStar. At the time I drew to the company's attention some misleading suggestings in a very informative information screen on the disc (it is hard to find -- you go to 'Bonus Materials', then select the right-hand pointy end of the yellow arrow above 'Menu'. You will know you have selected it because the point will turn orange. Press 'Enter' and repeat on the next screen. Then choose 'Technical Information'.)

Here are a couple of snippets from this:

Four D-1 component videotape submasters were "downconverted" from the OUT OF SIGHT HD master: NTSC and PAL 3:4 hard-matted widescreen, plus NTSC and PAL 16:9 which are the source elements for DVD release.
Well, it looks like we scored the 3:4 hard-matted widescreen, not the 16:9. It goes on to say:
The 5.1 [audio] master ... was then transferred to the AC-3 Dolby Digital coding at a rate of 448kbits/sec via a Dolby 561B encoder.
Sorry, the PAL DVD uses 384kb/s.

Now the Columbia TriStar release of this title did not suggest on its cover that the DVD was an anamorphic transfer. But now that Universal has taken over distribution of its own titles, things have got worse.

First, the DVD itself seems to be identical in every way to that previously distributed by Columbia TriStar. Yet the cover is different. Here is the disc information block in its entirety:

Disc information block for the Region 2/4 version of 'Out Of Sight'
Note, in particular, the aspect ratio claim near the top-right: '1.85:1 Anamorphic Widescreen'. This is wrong and misleading. The movie on the disc is in 4:3 hard-matted widescreen. The quality is, therefore, substandard.
The Real Starship Troopers - Thursday, 11 March 2004, 9:36 am

There were many, many disappointments in Paul Verhoeven's 1997 movie Starship Troopers. Those of us who love Robert A Heinlein's novel object to the political re-orientation in the movie, the idiotic 'science' and the unbelievable contrivances used to have the characters stumble across each other at various points. One less objectionable, but still disappointing, omission from the movie was Heinlein's 'Powered Armour'. He clearly had a love affair with the concept. It was the device that made his Mobile Infantry mobile.

In recent years the US Defence Department's DARPA (Defense Advanced Research Projects Agency) has been funding development of something very similar. Now, it seems, a working prototype of the leg enhancement and load-carrying part has been developed by the Berkeley Robotics Laboratory.

From the always-exciting FuturePundit article on the subject:

In the UC Berkeley experiments, the human pilot moved about a room wearing the 100-pound exoskeleton and a 70-pound backpack while feeling as if he were lugging a mere 5 pounds.
And this is only the first version.