24fps 120hz etc. Help

Hold on, folks, you are all ahead of yourselves. nickle15, when you feed a 60Hz video signal to a 120Hz set, it will look much the same as it does on a 60Hz set, and technically, you will be using 2:2 pulldown from 60Hz to 120Hz.


For TRUE 24fps operation, you need a Blu-Ray player capable of outputting the native 24fps Blu-Ray disk content. That is definately NOT a feature that is available on all Blu-Ray players, nor is it enabled by default on any Blu-Ray player, because most displays are 60Hz. If you want 24fps playback, you must have a newer player that supports it, and you must then go into the setup menu and turn the feature on.


I use a PS3 for Blu-Ray playback at 24fps, and a Toshiba HD-DVD player for playback at 24fps, and a HTPC that can be set for 24fps playback from vanilla DVDs, after "reverse telecine processing" that recovers the original 24fps film frames from the disk.


Now, once you have the 24fps video signal working, THEN you can play around with the various settings for frame interpolation, and decide if you like it or not.

Rocky1, the SOE is the opposite of what you are used to seeing on a video display.


You probably grew up as did most of us, watching NTSC standard-definition programming, that for the most part was shot on FILM at 24fps. Then the film was "telecined" to broadcast this 24fps over a 60Hz NTSC video signal, which gave a distinct and uneven on-screen motion to moving objects, and frequent "artifacts" which resulted from interlacing.


The other and less utilized practice for recording video productions, was to shoot the production straight onto video tape at either a 30fps or 60fps frame rate. This provided an extra clarity and a natural movement that film material lacked. For many years the main uses of video recordings were 1) Soap Operas and 2) camcorders used for news broadcasts. These 30fps or 60Hz video recordings (interlaced to 60Hz), displayed an extra clarity not seen on film recordings.


In truth the 24fps film standard was established by Thomas Edison in 1896, with the motive of standardizing the commercial theaters for more profit, allowing any studiio's film to be shown in any theater. For over a century, 24fps was THE standard.


Nowadays with ATSC broadcasts, many prime time series are shot directly onto videotape, such as the "Law and Order" series, with the irritating hand-held cameras. But the ATSC standard does not allow enough bandwidth for a 720p60 broadcast when the camera pans - it forces every pixel to change in every frame, and the digital compression is overwhelmed and the image displays a flaw called "macro-blocking of pixels", especially if some of the bandwidth was stolen with multiple SD "sub-channels".


However when that same video signal is played back from a DVD or Blu-Ray disk, there is not a bandwidth limitation, and incredible fidelity can be had. For example, stick a Blu-Ray recording of the BBC series Planet Earth into your player, and output the 60Hz video signal to a 120Hz or 240Hz LCD display. The result is incredible fidelity, as good ast it gets - you almost get vertigo and think you are looking through a pane of glass into another world.


That is SOE. Some of us LOVE IT, because it frees us from the 100-year-old limitations of film.


Nickle15, the 24Hz video will look nearly exactly like film in a theater on a 120Hz display, a series of frames where the image changes 24 times/sec. With frame interpolation OFF, the output frame buffer of the display will repeat each input frame 5 times, "5:5 pulldown", and if you are viewing in complete darkness, it will look remarkably like film. However if you turn on room lighting, you will start to notice flicker as the 24fps video and the 60Hz lighting interact at night. You can minimize this effect by using incandescent room lighting, which does not vary in intensity as much as does flourescent lighting.


But IMHO the very best result involves MCFI, Motion Compensating Frame Interpolation, which synthesizes frames between the input video frames. Film lovers call it "SOE" and discuss it as being "unreal". I find this curious - because the high frame rate video approximates real life, where objects have an effectively infinite frame rate.

MFCI has nothing to do with being more "realistic" - it's designed to mitigate a shortcoming in sample-and-hold displays like LCD that causes people to perceive blurry motion. The look imparted by MFCI - especially with 24fps material - is even more artificial than the look imparted by film. Film only captures real motion (obviously with certain artifacts depending on the speed of the motion), whereas MFCI has to make basic assumptions about all motion to create artificial frames, linearizing movement where it is often not supposed to be linear, hence the "cartoonish" or "fast-forward" look. I'd rather watch material captured at 24fps at its native framerate rather than displayed at 240fps with multiple artificial, unrealistic frames in between each frame; most people I've talked to about this in person feel the same way.


Once again, the sole purpose of a display is to accurately reproduce what's sent to it - not to simulate reality. Most material that we watch is meant to simulate some sort of fantasy, not recreate reality; a good display will reproduce realistic and fantasy material equally well while a poor display will not. If all people want is reality, they should be out in the real world using all of their senses and not trying to artificially recreate it on a display with processing trickery.

Maybe someone can explain:


1. If a 24 fps movies is displayed on LCD at 120 or 240 Hz or even on plasma at 72 or 96 Hz how is the motion blur or judder improved that is inherently in the film because of the lousy 24 fps by simply by repeating the frames.


2. To improve the judder or blur to some extent, do you not need some sort of frame interpolation instead of just repeating the same frame multiple times?


Some TVs have separate blur and judder controls and one might be able to dial in the right setting which helps these artifiacts lessen without making it look like video too much.


BTW, why is 24 fps look realistic? I find the blur/judder in 24 fps annoying and I am not sure why some are hung up on it. It is a 100 year old concept we need to move on to higher sample rates, no? (p.s. I do not like the soap opera look myself either, but do not accept the shortcomings of 24p film either).



Quote:
Originally Posted by dandaroy /forum/post/18170662


Maybe someone can explain:


1. If a 24 fps movies is displayed on LCD at 120 or 240 Hz or even on plasma at 72 or 96 Hz how is the motion blur or judder improved that is inherently in the film because of the lousy 24 fps by simply by repeating the frames.

Click to expand...

Adding synthetic frames and refreshing the display at a higher framerate doesn't fix motion blur that's captured on the film, that's inherent to the source and not caused by the display. Judder is something different altogether, and is fixed by displaying 24fps material at some multiple of that rather than using 2:3 pulldown.

Quote:
Originally Posted by dandaroy /forum/post/18170662


BTW, why is 24 fps look realistic? I find the blur/judder in 24 fps annoying and I am not sure why some are hung up on it. It is a 100 year old concept we need to move on to higher sample rates, no? (p.s. I do not like the soap opera look myself either, but do not accept the shortcomings of 24p film either).

Click to expand...

Film isn't realistic - as with any other art, as a medium film has certain visual characteristics which result from its physical structure and the capture speed. Maybe some day when digital capture becomes more prevalent and can approach the abilities of film, directors will be able to choose from a wide variety of "looks," one of which could be that of film. However I'm a huge proponent of using higher capture framerates to eliminate the artifacts caused by recording various rates of movement at 24fps. That being said, as long as the majority of movies are shot on film, I really don't think we'll see an increase in capture framerate since - for example - 48fps would double the amount of film (and associated costs) required. For the time being I think that the benefits of film over digital capture mediums still far outweigh the drawbacks, but maybe some day that will change.



Quote:
Originally Posted by HogPilot /forum/post/18170801


Adding synthetic frames and refreshing the display at a higher framerate doesn't fix motion blur that's captured on the film, that's inherent to the source and not caused by the display. Judder is something different altogether, and is fixed by displaying 24fps material at some multiple of that rather than using 2:3 pulldown.

Click to expand...

Understand about the blur, but how is judder improved if the frames are just repeated rather frames inserted (regardless of how it looks). If the frame is merely repeated since it is the same frame, how would that help judder? Maybe I do not understand how judder gets in 24p film (I understand how it does in 3:2 pulldown, but we are not talking about that).


Care to explain? Also if you could answer my other recent thread, I would appreciate it.

I think your getting judder and film edge flicker confused


judder is only seen in films where there is something moving at a constant speed on the screen like when a camera pans or when credits are rolling at the end of a movie and what it does is makes it look like its studdering or moving at a different rate when it should not be


film edge flicker is the blur created by fast moving objects that is also very commonly noticed in the very same panning scenes as well as the credits and is due to the low frame rate of film


think of it like this every dash i put below is a frame


3:2 pulldown judder

--_--_--_--_--


the - is a frame at normal speed

the _ is a lengthened frame to make up for the difference between 24 and 30 fps so smooth motion appears to studder on the screen


2:2,5:5 pulldown looks like this

---------------

every frame is displayed for the same amount of time but you still see edge flicker and you see it much more on LCD's than on Plasma, CRT or film in a movie theater because of LCD's sample and hold type of display combined with LCD's overall poor pixel response time in comparison to the other common tech's out there


if you don't believe me or understand what I'm talking about go see a movie in the theater (not one using a digital projector or IMAX either because they do not look the same as normal film projection) and you will see that film edge flicker is there as well, its part of what makes movies look like movies and motion enhancers work to remove that look from them in order to make motion appear smoother on an LCD


this is one of the reasons why plasma is the preferred display type for movie watching even with judder motion in films looks more natural overall than on most if not all 120/240 hz LCD's