The VideoLAN Forums

I noticed there are new widescreen tv displays that are so called "120hz" displays. Samsung's name for it is "Auto Motion Plus" and Sony calls theirs "Motionflow".

Basically what these 120hz TVs do is convert 24p video to 120p by interpolation (24hz x 5 = 120hz). They basically fill in 4 extra frames between each frame giving the video a highly realistic 3d feel.

What I would like is a post-processing feature that allows this 120hz emulation (or even 60hz will be fine)

I wouldn't want to spend $3500 on a 40in 120hz LCD TV just to get this feature. LOL

That would be pretty cool. Seconded.

if pointed in the right direction I may be able to write the portion of code myself.

You don't need any code =)
24 -> 120 is only needed in display device. And I am fairly sure that most display devices wouldn't even accept 120 FPS input (excluding some CRT monitors).

Operating systems make sure that you see your 24 fps video in 50, 60, 72, 85 Hz or what ever refresh rate your display device has and OS doesn't do interpolating, so it is almost same thing (showtime for specific frame ain't guaranteed, but it really can't fixed in any reasonable way). Running video material on higher refresh rate than your monitor has no advantage at all. Without Vsync it even causes tearing. (Gaming is an another topic).

I fail to see how that would be of benefit. The human eye cannot detect pauses at much above 15fps. The reason the 120Hz conversion is done is to keep the post-processing of, for example, 24p as a nice integer value. If there is any bilinear interpolation etc. done on the frames then there still would be no visible difference. The problem with e.g. NTSC televisions is that 24 does not go into 30 very well, which can result in a "jerky" image.

The only problem you may encounter would be vsyncing problems with a monitor, however there are method for fixing that.

Arite.

I'm not sure if you guys know what I am talking about. Go to your local Best Buy or Circuit City and ask to see their 120hz televisions.

Sorry, I misread on first time. I confused frame multiplication to motion tweening. So you want something similar than ConvertFPS filter in AVIsynth?

I found this thread and was wondering if anyone has found a way to do this yet?

If you havn't seen one of the 120hz LCDs.... you should check them out... they look amazing

I would kill to have a picture like that on my computer monitor....

what about re-encoding some vid with 120fps, seeing if that makes any difference on a normal display ? (decoding would be 5x more CPU hungry i guess)

In order to watch the video with 120fps you still would need a monitor with 120Hz... so you won't get around buying a new device. This feature request technically makes no sense.

Can this be done? What is the status of this? I'd like to do this. People say you can't see the difference between 24fps and a let's say 50 fps, but IMO that's not true. I can see a clear difference, the latter being a lot more smoother.

It is almost trivial to implement this if you just create extra image from average of two frames, but I am not sure if it looks OK (it will eat more CPU and needs more memory because of needed math operations and because of double FPS requirement for output).

this still doesn't make sense.

Point is to create frames so the playback will look smoother. If you have AVIsynth installed you check my examples.
http://koti.mbnet.fi/raiska/fps/30fps_skull.avi
http://koti.mbnet.fi/raiska/fps/60fps_skull.avi
first download those. Then download
http://koti.mbnet.fi/raiska/fps/fpstest30-60.avs
http://koti.mbnet.fi/raiska/fps/fpstest30-30.avs

fpstest30-60.avs shows that generating frames ain't that good solution as original high FPS video (left is 60 fps, right is 30 fps converted to 60 fps).
fpstest30-30.avs shows that generating frames is little better than just duplication of frames (left one generates new frames, right one duplicates, both go 30 -> 60)

fpstest30-30.avs video on left shows what feature people are looking and right one shows the current situation where OS multiplies frames.

You can use notepad to edit those avs files to generate higher FPS. I chose 60 FPS because most LCD monitors are limited to that.

I am still not convinced there is any perceivable difference between the 30fps and the 60fps stream, although the human eye is reported meant to be able to detect up to ~60fps (15+fps is where things appear to be fluid). The best way to compare the two would be to ABX them (an audio listening test technique) where by there is an A and a B sample, and X, a randomly selected sample, is played back. The listener(/viewer) then identifies the X as either A or B. The trouble with knowing that one is a 60fps one is that you automatically convince yourself that it looks "smoother" than the other.

Arite.

The problem still is that you can might be able to calculate the video up to 240frames per second or whatever but if you don't have a monitor or TV that has such a high frame rate its useless, as you only will get to see the limited number of frames. And the initiators of this thread thought they could avoid buying a new TV by just calculating new frames.

There is a filter available for ffdshow to do this.



ffdshow Properties / Deinterlacing / Method: Framerate doubler

Then you can select between:

a) No motion estimation - blend images. (low CPU usage but very poor result)
b) Current location only.
c) 1 pixel motion, left & right. (I think this is the best option).
d) 3x3 square.

Pros: NTSC 30fps source => 60fps / PAL 25fps source =>50fps. More real and natural feel (a little improvement).
Cons: Activate this filter with HD content requires a lot of CPU. Some people and most old people don't appreciate the difference. The video player must activate some VSync method.

I think make a 5xfps is a madness because it requires a LOT of cpu (120p TVs use specific hardware optimized to do that) and most screens are 60-85Hz. But a 2xfps filter will be brilliant.

Hi
I am using VLC for years (as most other people I know). Recently I started watching DVDs on a project and now Ireally want to second this feature! It sounds trivial to implement for normal PAL-resolutions and doable for 1080p with GPU-Shader stuff. Requesting 120FPS is of course useless, but most LCD do 60FPS and my projector does 75. This makes a tremendous difference especiallay with reducing DLP-Rainbow artifacts. I just can't believe you can't see the difference between the 30 and the 60FPS example posted above! This is so obvious. Show both to your grandma and she would see it. Try it with realtime generate images (e.g. Computer-Games). If you can't see the difference, well: Then you are lucky.From doing some user-tests at work, I can tell you that most people can instantly spot the difference. Although some they can't name it, literally everybody prefers higher FPS.

Please, I beg you. Implement it as an experimental filter plug-in. I mean you have features like a "Puzzle Game"...

I also want to request this feature. Cyberlink is currently doing this in PowerDVD 9 (only for DVD, though, not for Blu-Ray), it's called "TrueTheater Motion".

I'm still not sure I like the look (it is different than the film look we get used to with 3:2 pulldown or simple frame repetition), almost makes it look like it was shot on home video. I have also seen the 120/240 displays in the big box electronic stores, and it is a very interesting look. It does almost look 3 dimensional. I think they choose 120/240 because they are multiples of both film (24) and NTSC video (60). I saw a Blu-Ray of Dark Knight on the display and it was quite a mesmerizing effect to see the frame interpolation. For those of you who doubt the point, I will tell you it does make a noticeable difference and if you play with PowerDVD 9 you can get a taste of it.

Of course the issue of most modern displays only going up to 60Hz is valid, but don't forget the home theater community that uses Home Theater PCs connected to big screens. I want to get a 120/240 display in the near future for my home theater, and I guess if I set the display to 60Hz it will do interpolation automatically in the display (but even then I question the source material doing frame repetition to 60Hz) but if I set the refresh rate to 120Hz it will display exactly what the computer is putting out.

At very least on 60Hz displays VLC can do what PowerDVD is doing.

Those 120/240 displays don't accept 120 or 240 FPS input. And they don't really even display 120 or 240 FPS. They use back light tricks to make human vision system assume that the FPS is higher.

Those 120/240 displays don't accept 120 or 240 FPS input. And they don't really even display 120 or 240 FPS. They use back light tricks to make human vision system assume that the FPS is higher.

I know this thread seems to be basically dead but I can't let that comment stand.

First of all, the 120hz tvs CAN accept 120hz input if you use the right cables (namely hdmi) same with the 240hz tvs.
Second, I was a rep for Sony for a while and they have NEVER used that half-assed trick. That was only done for a very short time by a couple of the cheaper brands (though Visio still does it with their 240hz SPS system which is really just 120hz with the scanning backlight you're talking about). The real benefit of the 120hz is the fact that it forces the system to respond faster and get less blur. The benefit of the 240hz is the same thing but is capable of running 3d because when you run 3d on an LCD you need 4 frames instead of just right and left eye frames. It goes: right frame, black frame, left frame, black frame, etcetera. This helps clear the image so you don't end up with a ghosting effect.

I have been researching getting the 120hz working with VLC as I am running a 120hz capable projector and I am trying to smooth out the video the way Sony's motionflow does by adding extra video frames in between. Though on a DLP projector the response time is far better so have less chance of a ghost effect anyway.

I request that feature too... currently Im using frameratedoubling with Avisynth scripts and works fantastic..

The script interpolate frames.. so a movie at 30fps is played at 60fps that match perfectly the 60hz refresh of monitor!!

OK if you have a 120hz monitor.. you need to interpolate more frames...

Plz add this feature!!! really is eye looking... much better than this motion blur filter

I fail to see how that would be of benefit. The human eye cannot detect pauses at much above 15fps. The reason the 120Hz conversion is done is to keep the post-processing of, for example, 24p as a nice integer value. If there is any bilinear interpolation etc. done on the frames then there still would be no visible difference. The problem with e.g. NTSC televisions is that 24 does not go into 30 very well, which can result in a "jerky" image.

The only problem you may encounter would be vsyncing problems with a monitor, however there are method for fixing that.

Arite.

actually yes it can, like if you view the screen from the side of your eye you can see the black or refresh rate whatever you wanna call it.

I'm seconding this one as well. If my memory serves ~15 fps is the rate required to perceive motion but additional frames are still noticeable up past 60fps or so; and after seeing one of those TVs myself I'd love to have that feature on my machine.

what about encoding a video to emulate the smooth motion effect?

Is there software out there that would or could willingly add those extra frames in?