High Frame Rate Blu-ray?

[MediaMalable]

Someone recently told me that Blu Ray can't support the 48 frames per second rate that The Hobbit has been shot in. I'm trying to understand if that's true, and if so, why? My playstation 3 and television can play video games (off blu ray discs) that run at 60 frames a second. Why can't it display The Hobbit?

Help me understand!

[kpkelley]

My understanding is that Blu-ray can playback video from 1080p sources up to 24 frames per second and 1080i sources up to 60 frames per second.

This is part of the standard for blu-ray disc and player manufacturers. It's quite possible that the discs themselves could handle playback of 1080p sources at a higher frame rate, but they may not be able to be read by all blu-ray players. 3D movies are essentially being played back as 1080p/48, so it seems technically possible. The Hobbit however is also a 3D film, so that would be more like 1080P/96.

It will be interesting to see how they release this movie on home video.

[vargo]

A format like Bluray can only work if there is a rigid standard specification. And 48fps is not part of that because it is not a standard framerate.

Same for TVs. They accept input resolutions and refresh rates that they were designed to accept. Nothing more.

Bluray supports high framerates such as 50fps or 60fps. But at these framerates the resolution must be lower. There are technical reasons for this. They have finite processing power, bandwidth, ref-frame memory etc.

[lobosrul]

The spec only allows 1080p up to 30fps (that is h.264 level 4.1). Do not confuse that with a players ability to output at 60 fps. I'm not exactly sure why 1080p/60 wasn't supported, looking back it was very shortsighted. My guess would be back when the spec was finalized that was about the limit of the hardware, at reasonable prices anyways.

Its almost certain IMO that The Hobbit will be released on BD at 1080p24. 48fps telecined to 1080i/60 is a possibility, but that would be a screwed up cadence, causing weird jutter most likely. 720p48 is "within" the spec, but not a standard framerate and would not be supported by any TV's even if a player could output it (which I doubt). I guess in 50Hz countries they could speed it up to 720p50, which would work, I just don't expect it to be done.

[BozQ]

I think lobosrul pretty much found the compromise. Without doing any revision to the current Blu-ray specs, the only way to achieve HFR 3D on BD is to encode the video at a speedup rate from 48fps to 50fps, @720p50, with SBS or TAB 3D.

Unless the reception for HFR and HFR 3D is popular, don't expect the Blu-ray committee to quickly revise the specs again.

Blu-ray adoption took long enough as it is, and we can pretty much get away with the 3D BD as a gimmick. But to try and sell HFR 3D BD to the common consumers is not going to be easy.

[joie]

Is 3D is being displayed at 48 fps?
I'd guess that it is 24 fps, alternating frames for one eye with frames for the other eye, which makes the effective frame rate 12 fps, but the brain's "post processing" makes it seem like 24 fps.

[lobosrul]

Originally Posted by BozQ

I think lobosrul pretty much found the compromise. Without doing any revision to the current Blu-ray specs, the only way to achieve HFR 3D on BD is to encode the video at a speedup rate from 48fps to 50fps, @720p50, with SBS or TAB 3D.

Except, it won't work in N America, or Japan. Some TV's sold in 60Hz countries will accept 50Hz signals, but many will not.

[Anthony P]

Originally Posted by lobosrul

Except, it won't work in N America, or Japan. Some TV's sold in 60Hz countries will accept 50Hz signals, but many will not.

also the BD player could be an issue in those countries, so it is not just the TV

(not to play down the issue of speed-up which will deteriorate the sound and that we are talking 720p)

[ZoetMB]

Originally Posted by joie

Is 3D is being displayed at 48 fps?
I'd guess that it is 24 fps, alternating frames for one eye with frames for the other eye, which makes the effective frame rate 12 fps, but the brain's "post processing" makes it seem like 24 fps.

The Hobbit was shot at 48fps in 3D. So that means either 48fps to each eye or 24fps to each eye unless they double the frame rate when they make the 3D "prints". It would not mean 12fps to each eye in any case. If that were the case even when movies are shot at 24fps, if you closed one eye while watching a 3D movie, you would have very jittery movement, somewhat like an old silent film that was shot around 16fps. That's not the case.

I suspect it's 48fps to each eye. If it were 24fps to each eye, we shouldn't see "soap opera effect" and there have been complaints from previews that "The Hobbit" does experience that.

[WiWavelength]

Since the 3D frame packed BD format operates essentially at 48 fps (24 fps per eye), I have long theorized that "The Hobbit" would be possible on BD as 2D 48 fps.

The BD would technically be encoded in the 3D frame packed format, but instead of left/right frames being packed together, odd/even frames would be packed together. It would be watched without glasses, such that both eyes would see each frame for a total of 48 fps.

Of course, the process would work only with active 3D displays, not passive 3D displays. So, the chances of such a general BD release happening are essentially nil because consumer confusion would be rampant.

AJ

[vargo]

Originally Posted by WiWavelength

Since the 3D frame packed BD format operates essentially at 48 fps (24 fps per eye), I have long theorized that "The Hobbit" would be possible on BD as 2D 48 fps.

The BD would technically be encoded in the 3D frame packed format, but instead of left/right frames being packed together, odd/even frames would be packed together. It would be watched without glasses, such that both eyes would see each frame for a total of 48 fps.

Active 3D displays don't play their frames in a simple sequential order at 48Hz. It would be too flickery. For a single temporal frame, they show the left and right side multiple times alternately before moving to the next one.

So if you tried to pack 48fps like this, the TV would rapidly flick back and forward temporally.

[Gally]

Originally Posted by vargo

Active 3D displays don't play their frames in a simple sequential order at 48Hz. It would be too flickery. For a single temporal frame, they show the left and right side multiple times alternately before moving to the next one.

So if you tried to pack 48fps like this, the TV would rapidly flick back and forward temporally.

It's not really a matter of how the display interprets it though. With a simple firmware update, any 3D compatible Blu-Ray player could be configured to decode a 48 fps video stream, and output it at 60 hz for the monitor. Or True 48 presumably for a high end player to take advantage of a 240 hz monitor and eliminate 2:3 pulldown.

[vargo]

Originally Posted by Gally

It's not really a matter of how the display interprets it though. With a simple firmware update, any 3D compatible Blu-Ray player could be configured to decode a 48 fps video stream, and output it at 60 hz for the monitor. Or True 48 presumably for a high end player to take advantage of a 240 hz monitor and eliminate 2:3 pulldown.

Radical firmware updates and changes to Bluray spec are never so 'simple' unfortunately. It is not something you do on a whim for one movie.

If you find 48fps output at 60Hz with pulldown acceptable you would simply apply the pulldown during encoding and present it as 720p60. No update or spec revision necessary and every player can handle it.

However most people would not find that an acceptable solution. 48 into 60 gives a hiccup judder similar to euro pulldown which many people find much more noticeable than 3:2 judder.

[Prox]

How was this issue addressed when 3D was added to Blu-ray?

[Penton-Man]

Originally Posted by Prox

How was this issue addressed when 3D was added to Blu-ray?

By having included 720p60 in the Blu-ray spec, as indicated here…
https://forum.blu-ray.com/showthread...ng#post6832063

If my brain has woken up by now helped by a caffeine kick, the HD formats which Blu-ray supports include: 1080p24, 1080/50i, 1080/60i, 720p50, 720p60 (with the caveat that for 3D, the 50i and 60i versions are N/A).

The choices for which a theatrical 3D 48 fps film could be released onto Blu-ray now would be either as 1080p24 or 720p60. If WB or Park Road tried to convert The Hobbit to Blu-ray 3D 720p60 for the home theater enthusiast, as vargo indicted above, it might very well judder from the uneven frame rate conversion, plus/or you'd have frames blended together/interpolated.

[vargo]

Originally Posted by Prox

How was this issue addressed when 3D was added to Blu-ray?

They updated the Bluray specification. Backwards compatibility was a very important issue.

But the key with 3D was that there was an industry wide push with hundreds of movies on the horizon and it was supposed to be the 'next big thing' that sold more TVs and players.

[Prox]

Thanks, guys.

So the thing with 48 fps is that, though it would be possible to update the Blu-ray spec, there is not yet enough demand/push for it which means they would have to shoehorn it into an existing offering?

[ronjones]

The next generation HDMI spec. will be released very soon as will the H.265 spec. Based on what info I've seen both of these support 1080p at higher frame rates as well as 4K video at up to 60Hz. In fact the H.265 spec. supports up to 8K video. H.265 offers twice the compression rate of H.264 for the same video quality, but requires more processing by the encoder and decoder. Both Sony and LG reps over the past 15 months have said (going as far back as a Sony rep's statements at Cedia Expo 2011 and LG at a couple of trade shows this year) that an upgrade to the Blu-ray standard is expected to support 4K video and I would suspect also higher frame rates for 1080p. LG reps have specfically mentioned they expect to see the first of these 4K blu-rays by the end of 2013. However, I have seen no official timetable from the Blu-ray Disc Association. Hopefully this next generation Blu-ray will also add support for H.265's upto 12-bit color depth (instead of the current blu-ray 8-bit limit). The H.265 codec will be backward compatible with H.264 (used by current Blu-ray) and a next generation blu-ray player will naturally be required to play next generation discs (e.g, with 4K resolution, higher framerate 1080p, etc.). Such a next generation blu-ray player will, of course, be backward capable with all current blu-ray 2D and 3D discs. I would assume the transitiion of these next generation of discs (i.e., movies) will be handled by the movie studios in a similar fashion as is being used for Blu-ray 3D. We will likely hear more about all of this at the CES that takes place two weeks from now in Las Vegas (if not then probably no next gen blu-ray until at least 2014).

[nic727]

I read somewhere that to have more framerates you need more pictures/secondes, but bluray can't have all of that in the disc, but if they put that in 2 disc it could work (talking about The Hobbit). And i read too that bluray can read 60fps in 1080i instead of 1080p.


Thx

[Anthony P]

Originally Posted by nic727

I read somewhere that to have more framerates you need more pictures/secondes

yes, that is the definition of frame rate (how many pics a second, 24p means you have 24 of them and 48p means you have 48)

but bluray can't have all of that in the disc, but if they put that in 2 disc it could work (talking about The Hobbit).

it is not about disk space, well it can be especially for a long film like the hobbit but that is not the primary issue. For example a 1.5h movie in 48fps will have as many frames (pictures) as a 3h film that is 24p. The issue is that formats have specs, specs are rules , when BD was being worked on before 2006 there were no films in 48p there was no 3D... so they made the specs for what was available. Now eventually they upgraded BD specs and added 3D and maybe one day they will upgrade it again and add 48p (if there is demand like with 3D) but then you might need a new player (i.e the machine you have was built to handle 24 pictures in a second if it needs to handle 48 that means a lot more work and it might not have the computing power)

And i read too that bluray can read 60fps in 1080i instead of 1080p.

yes the specs are 1980p24, 1080p30, 1080i60, there is no 1080p60 (there is also 1080p25, 1080i50 for places that use 50Hz like Europe)