Home theatre 24p Digital receiver

[[DANGERDAN]]

Basically i love the way movies look with 24p on, so much less judder/stutter and is a lot smoother. I run the movies via hdmi from my computer and just switch refresh rate to 24hz. But now i am wondering how can i do this with digital tv from my uhf receiver, I know i could probably buy a digital tv card and put it into my computer and run it through that but i was thinking there might be a easier way like a digital receiver that outputs 24p etc.

Any ideas would help lots thanks

[Serra]

I don't understand. How is 24 frames a second smoother than 60 frames a second? Or even 120/240 with interpolation? When I watch a 24p movie (eg in a theater) I know I can see frame changes, and I am by no means visually gifted.


I think a digital TV card would probably be the best way to go though... though I'm still baffled as to why you would want to do it...

[Bobsama]

Setting refresh rates for LCD's is basically pointless; setting low just limits how often your graphics card sends information, but it doesn't change the actual refresh rate of the screen. And 24 fps is rather noticeable, though less-noticeable than a half-frame (ie: 29.5 fps).

I haven't heard of any modern AV receivers with that type of specific feature.

[[DANGERDAN]]

I don't understand. How is 24 frames a second smoother than 60 frames a second? Or even 120/240 with interpolation? When I watch a 24p movie (eg in a theater) I know I can see frame changes, and I am by no means visually gifted.


I think a digital TV card would probably be the best way to go though... though I'm still baffled as to why you would want to do it...

Very simple to say because all and most movies only record at 23.97 fps across everything, when you buy a Blu ray movie it says its 1080P and usually you would think P would be 60hz but that's just stating its in progressive format but its still only running in 24fps, and why 24hz is better is because no frames are being repeated to match the 60hz frequency, repeated frames clearly shows stutter and jerks when watching on big lcd or plasmas.
With interpolation its not very good, for some people it can make tv viewing bad because its trying to predict and create a image by viewing a frame by frame prediction processor and creates a artificial look and stutters in some un predictable scenes.

[Serra]

I'm not sure I follow you. You said that "repeated frames clearly shows stutter and jerks", and I don't see how. For example, if I view frame A, then frame A, then frame A all I'm seeing is frame A. There's no jerk because, strictly speaking, there is no change on the screen. As far as the "24 doesn't divide into [60/50] fps, and that causes stutter" argument goes, the speed of the film itself is sped up to make the division even. What you get now is digital 1080p60 (for HD)... not 1080p24 that is then converted by your player to 60fps. For example, a movie in PAL format is slowed down 4% so the division works out properly. By doing this they eliminate all jerking and/or stuttering. Now what is really funny here is that when you slow down your video system to 24fps you don't actually re-claim that gained/lost speed - all you do is retard your system from functioning the way it was re-mastered to and actively introducing stutter yourself! Because although they sped up or slowed down the film, you aren't speeding or slowing the actual content (just how often you see it), and you're actively trying to push 60 frames into a 24-frame timeslot, which as we know does not divide properly!

I also don't really see how interpolation is that bad either, good quality interpolation acts like motion blur, which helps the human brain process movies. Something like a scene change can break the system, but these days good motion engines look sufficiently far ahead to be able to say "hey, scene B is nothing at all like scene A, therefore I won't create new scenes between them". Back when interpolation was first coming out, yeah, but it's definitely more advanced than it was a decade ago.


No, no... the idea that it's better to run your system at 24 fps is one of those that you see come up on occasion, but in the world of VHS/DVD/BR it just doesn't make sense like it would if one was thinking about film because everything is already re-mastered for 30/60fps delivery BEFORE you touch it.


Also, is it even still true that movies are filmed at 24fps on average? I mean, I know that cameras made as early as in 1995 (and probably earlier, I just know 1995 for sure) could do 150 frames per second handily and were widely adopted. I just can't imagine that new feature films - take Iron Man for example - was filmed at a snails pace of 24fps. Feel free to correct me on that as I couldn't find any information about it for any of the movies I looked at, but it seems like it would be silly to film anything at 24fps these days.


Edit: At the end of the day, if you like playing at 24fps then by all means go and do it. Movies are about creating an enjoyable experience.

[Bobsama]

LCD's always refresh at their rated rate; they're not adjustable like CRT. That means that your 60hz screen or projector will ALWAYS run at 60hz, regardless of what you set it to. The same applies for 120hz and higher panels; they will ALWAYS run at that rate.

[zanzabar]

i agree with dan on the 24hz for bluray if u have a 120hz real or a good 2:3 or 1:5 pull down on a 60hz or fake 120hz or the other ones, but for TV unless u are in japan ntsc is 30hz (or 29.5) for DTV, so limiting it to 24hz would not help anything it would make it worse, also going from a PC u want to send out 60hz as a computer will do better pulldown than any tv will, doing that with a blu ray player is debatable though. the artificial frame is motion processing and that is never a good thing, but if u use motion focus it can be good as that will improve the time it takes a pixel to change colors but it can cause instability on stills so it all depends.

@serra iron man was captured at 96 or 48 fps as it was imax and imax is 48hz so depending on how the post is u need it to be 48 or 96

[[DANGERDAN]]

Haha this has turned into a nice discussion xD, anyways yes technology can capture more than 24fps even 1000 fps but the filming industry decided that 24fps was the best fit for cost effective and performing film because filming even at 30fps would increase cost production by 30 percent so having it at 24fps was the best fit. 24 fps movies shown in a 60Hz output have a 3:2 cadence of repeats of the frames and will show judder when things move.(google 24p) Interpolation was invented to try and double or triple the 24fps frame by inserting artificial frames in between every real frame, it can be good but to the sharp eye people like myself you can tell its on and it doesn't look good.

24p is better because its reproducing the image as it was recorded and not being repeated or having a pull down effect which causes the judder. xD

@zanzabar
Do you know if iron still kept its high frame rate when place on blu ray ??

[zanzabar]

it should be 24 on the blu ray as they are all 24 or 60 for normal disks, and nothing would be able to play a 48hz video anyways other than a pc for home equipment.

and i dont think that u get 2:3 pulldown, that will make it hold a frame for extra then the next for extra then not hold and repeat, if u have a good TV for it like a panasonic they will even short the holds so it looks smoother like a dlp or crt would or plasma or 1:x pull down anything else. its just a matter of getting things to hold as evenly as they can so u dont get things jumping across or get uneven fps. so if u have something that can give u a good native 60hz on a 60hz panel then u should use that if u have a 24hz source then if u have something that will give a good conversion to 60 u should do that but other than a computer its not going to happen so thats when u have to decide what is better. also if u have a bad hdmi cable or get interference/degradation so u cannot get 1080p60 with the cable then 1080p24 can also be great

[[DANGERDAN]]

Thanks for you help, Yea i know when there's live TV like sport or something they have a very high frame-Rate but i am guessing that's because its being streamed and not stored. Problem is with digital tv 1080i and 720P on my 46inch led tv it has a bad pull-Down effect and has a :banana::banana::banana::banana: load of judder so trying to find a way to reduce this by forcing it to 24P.

[zanzabar]

what unit do u have, and what service/box

[[DANGERDAN]]

The digital receiver is inbuilt in the tv, the service we have here is called freeview tv coming from uhf antenna and most channels are either 1080i or 720P

[Serra]

Hmmm, did some Googling and you're right (well, for the US). PAL regions do undergo a content slowdown of 4% but US/Canada don't (eg. look at the run-time differences between US and Australian versions of a movie). Interesting. Am I the only one who hates that we don't have rational global standards for this kind of thing? Jeez!

So yeah, I suppose the best answer is just to use a true 120Hz TV or do what you're doing, in which case I would still think the tv tuner would be the way to go. Imma go sit quietly now and see what else I can learn.

[zanzabar]

wouldent that mean that your in the UK so u would have pal and that would be a region 2 so u would have 1080p25 blu ray for 25hz and for tv wouldent u have 25/50hz.

what tv do u have, im not to familiar with non NTSC parts but its got me interested in this

[[DANGERDAN]]

New Zealand region 4 i beleive

[zanzabar]

so then that would pal-n and that one is also 25/50, so if u are trying to playback 24hz video i could see it not working properly with your tv. and new zealand and Australia are both region2 for blu ray so that should be 1080p25

what tv do u have i think that could be your problem

[[DANGERDAN]]

Samsung UA46b7000wm
This tv suppoers 23/24/25/26/49/50/59/60 hz refresh rate
I know i watched our soccer game live the other night and there was no judder, i think it was showing higher frames cause through live stream and that was why.
http://www.samsung.com/sg/consumer/tv-audio-video/television/led-tv/UA46B7000WMXXS/index.idx?pagetype=prd_detail&tab=specification

[zanzabar]

try turning off motion plus, and u may have to use overscan. im not sure why broadcast tv would do that though.

as for the 24hz working better for movies from the computer what other settings do u have to choose from for refresh rates as your tv is 50hz with fake 100hz but it looks like it can take in 60hz and the computer may default to that and that would be bad.

[[DANGERDAN]]

Motion plus is always off, with on it does look smoother but artificial looking and studders at times, the tv defaults at 60 hz when inserting hdmi or any other devices.
With overscan im not entirely sure what that is or if the tv has that option i may have seen that in the gfx panel however on the pc, Btw thanks for your help :)

[zanzabar]

did u try with your computer on 50hz

and overscan should be in the tv menu then picture options with the motion processing settings. u should have overscan dissabled as it takes out 7% of the pixels and then zooms

[[DANGERDAN]]

The digital receiver in the tv doesnt have the option to change the refresh rate other wise i would have changed it and it would be fine, if i got a digital tv card in my computer i could change it to a prefered refresh rate and it would be fine.

[[DANGERDAN]]

There's deffiinitly no overscan option, Colour tone,size,screen mode,digital nr,hdmi black level,film mode, 100hz motion plus,blue only mode, iv gone through my entire tv stripped it down xD update firmware iv done it all