Lack of smooth playback with Blu-ray

Last week I watched a film (I think it was the X-men) on blu-ray. Setup
was a 1080p/100Hz/24p full-HD TV. And a Ps3 blu-ray. On HDMI. (not my
setup btw, I don't have a blu-ray player yet)

While the details, colors is all superb there's something that annoys
the shit out of me: playback isn't as smooth as regular DVD.

I may be imagining things, but in moving scenes, or scenes where the
camera pans, I notice that the movement isn't completely smooth. It
seems as if there constantly is a few frames dropped for some reason.
DVD in that respect is much better, with movements fluent without any
"jerking" effect.

I have no idea what causes this, I mean the setup is pretty high end and
the PS3 supposedly is the best BR player around. Still, great colors and
detail are useless when the whole movie experience is ruined by constant
erratic behaviour like above.

Does anyone know what may be the cause of this? Is it inherent to the
Blu-Ray? If that's the case, it's a big no-no to me.

I'm actually not the only one noticing this, a friend, who has a high
end JVC TV and PS3 has experienced the same jerky effect on the Blu-Ray
of Wall-E.. And I've also seen it on the combination PS3 and a HD-Ready
screen (non 1080p compliant)

Is it the PS3 that screws the experience? Is it the HDMI standard?

I have no clue, but since there's only one common denominator above, I
bet the PS3 has something to do with it. Can someone chime in on this?

17 responses

I've noticed exactly the same thing with WALL-E as well. I haven't seen it on The Dark Knight, but that could just be that I wasn't looking for it. (Those are my only two BR discs atm.) It does seem very odd. On "action" scenes it's not too visible, but slow panning makes it very obvious.

No idea what's going on... but want to find out.

— Jon Skeet

@Jon keep me (us) updated! i don't have a BR (yet), and if this is consistent, I'm not going to get one either.

— Marco Frissen

Exactly the same happens to me. My set up is not that good yet should be capable of playing blu ray properley. I have a 1.83ghz duo processor and 3gb ram. I have a nvidia 9300m. My blu ray drive is linked to my laptop which then goes by hdmi to my tv. I thought that it was my graphics card or processor but the fact that such an advanced system like yours has the same problem is reassuring that there should be a simple solution. SOMEBODY PLEASE HELP!!!

— Jordan

Apparently "inverse telecine" is the problem. As I use a pc, cyberlink power dvd has this option. I will tick it and hope for the best. Yet on a ps3, I dont know, maybe there is an "inverse telecine" option in settings?

I don't see why inverse telecine should be involved at all. It should basically be 24Hz all the way. Jordan, do you have any evidence of this specifically for Bluray or better yet for WALL-E on Bluray?

The reason for the stuttering effect is 3:2 pulldown.

Feature films on Blu-ray and HD-DVD are encoded at their native frame rate of 24fps in all territories. Few TVs support a refresh rate that is a multiple of 24fps so the players upconvert to 60Hz using the 3:2 pulldown algorithm.

In a 3:2 film cadence the 1st film frame is shown 3 times, the 2nd is shown twice, the 3rd is shown 3 times, the 4th twice, leading to an uneven frame cadence of 3-2-3-2-3-2, and this leads to a noticeable stuttering effect on horizontal pans.

TVs that support the 1080p24 frame rate and can display it without judder and are beginning to appear in some high-end TVs, so it's only a matter of time before this feature becomes common. At the moment very few HD players actually output 1080p24. The PS3 supports 1080p24, you may need to update your firmware.

— Michel

Shouldn't I see it with The Dark Knight as well as WALL-E though, if that's the problem? My TV not only supports 24Hz, but is definitely using 24Hz when it plays WALL-E (it tells me the resolution and frequency if I ask it to). I entirely see why it would be a problem with a TV which couldn't cope with 24Hz, but if everything's doing its job properly there shouldn't be any need for frequency shifting.

Are you saying that you have the problem with the TDK and Wall-E and everything is set to 24p?

It could be that:
- You're TV detects a 24p but can't really handle it (no offense meant, thinking out loud...)
- You're sensitive and see stuttering at 24p (do you notice a slight stuttering in theatres? I do!)

It's pretty difficult to troubleshoot this from a distance.

I'm saying that I *haven't* noticed a problem with TDK (although I need to go back and check - it's more noticeable in slow pans without much action; not many of those in TDK) but I *have* noticed it with WALL-E, and everything is set to 24p. I'd be surprised if my TV didn't support 24p properly - it's a recent purchase and not a hugely cheap one.

I don't normally notice stuttering hugely, but again it could just be the kind of film that WALL-E is. A friend noticed the same thing though. Must try looking at TDK again tonight and report back...

(Yes, I appreciate the difficulty in long-range troubleshooting. I was interested to note that I'm not the only one seeing the problem though.)

You're absolutely right on the comment about slow pans with little action. The Lord of the Rings Trilogy is a great for testing panning issues. To my knowledge this hasn't been released on BluRay yet.

Wall-E is one of the two films I've seen in the theatre last year... I had some problems with panning, not much.

Also note that we've been a bit spoiled with quality in the last years. These problems are not new. I personally think these are visible because a lot of people concentrate on the technical quality (definition, sound...) and stopped watching movies.

I used to be a home theatre purist...NTSC dvd's on a normal TV also have the panning issues and I remember being the only one complaining about the panning :-)

I'm very interested in your findings during TDK.

Okay, I've just watched the first scene of TDK again - and it's definitely still there, but only when you're really looking for it. Not nearly as obvious as with WALL-E. I've rented Indiana Jones, The Prestige and Hancock to watch over the next few days - I'll keep an eye out. I'll also check whether there are any PS3 options which might fix it.

Rats, I was hopeful just now: I set "BD 1080p 24 Hz Output (HDMI)" to "ON" - but I there's no change in the results. The manual for my TV (32LG5700) certainly claims that it supports 24Hz. Of course, if it chooses to do that my inserting a duplicate frame to display as 25Hz, that would explain it (and be very annoying).

Okay, I'm pretty sure it's the TV. The same effect occurred on The Prestige, although we didn't spot it at all while watching the film - just watching the credits very carefully to see if it happened. (Credits are a good test, actually.)

Given that it's a stutter of once per second (not actually measured, but feels right), that the PS3 is configured to output 24Hz, and that I get the same effect without my receiver involved (normally PS3->Onkyo TX-SR606->TV, but connected directly for a test) it sounds like it's just the TV faking 24Hz by duplicating a frame per second. I suspect the TV's native rates are 25, 30, 50 and 60. The rest is just marketing. Drat.

Still, it's almost imperceptible (to me) for most films - just a pain for slow panning shots.

24hz support doesn't mean 24p! Only high end HDTV support tru24p, mostly sony's one. My LCD support 24hz, it just mean I can seen the image with BIG BIG jugger as it's displayed in 50hz. So force your PS3 to disable 24p, force 50hz. But even, 50 isn't twice 24. Only time will end this problem, when 24p will be common place. Perfect in time when BR will really replace DVD...

If only they would have opted for...
25p (europe yehaa.. but NTSC would wine=
30p (NTSC yehaa. but PAL would wine)

So, true 24p the only solution..

— Conrad

In fact, having disabled 24p on the PS3, it forces it to 60Hz rather than 50 - so each frame is shown for (alternating) 1/20th or 1/30th of a second; *every* frame is shown for the wrong length of time, but no frame is shown for a *very* wrong length. It looks a lot better having done that.

There is a a common misconception that what everyone is experiencing is a problem with their TV, blu-ray player or other setting. Generally however the problem is with the source material - the fact a film has been captured at 24 frames per second in the first place. When this frame-rate is reproduced accurately, as modern high-def TV / blu-ray 1080p 24fps discs / players do, you are seeing what is really there. Note this "stuttering" is not technically judder (the 3:2 pulldown thing discussed above which is a separate issue that is indeed eliminated by 24p playback).

You do see this at the cinema but the double shuttering of the projector helps reduce it significantly (and I think the background scenes are also typically slightly out of focus due to the limitations of the projector lens compared to your shiny new pin-sharp high-def 1080p TV).

This article gives some more info.

http://www.projectorcentral.com/judder_24p.htm

— catbus

@catbus: That would make sense in many cases, but not for Wall-E - it would be daft to computer-generate a film in anything other than the target frame-rate. I would be very surprised if this weren't just a problem with my TV "supporting" 24Hz by repeating a frame. It's not a *cheap* TV, but it's hardly top of the range either.

marco f dot net

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Lack of smooth playback with Blu-ray

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