Blur Busters Forums

vanden wrote:

James Freeman wrote:I've tested with 24 + 2*BFI @ 72Hz.
Every frame of the movie was shown only 1/3 of the time (41.7/ = 13.9ms) the rest is 2 black frames.
Smoothest video experience I have ever seen, even smoother than how they project in cinemas.
I think your brain completes the missing information, resulting in an extremely smooth look even at 24fps.
Almost looks like HFR (high frame rate).

I also tested ... but for me 24 + 2*BFI @ 72Hz or 24 + 3*BFI @ 96Hz is not watchable !
there are too flicker.

Here is an excerpt from a real movie or I see clearly the double-image effect (original 24fps) :
http://vandenk.free.fr/SVP/Home.Test-001.mkv

The same 2x faster (original 48fps)
http://e-nautia.com/vanden/disk/Publiqu ... 48fps).mkv

On my screen I see double-image effect on this 2 files ("original 24fps"/"original 48fps") ...

BFI :
96fps (original 48fps + 1 BlackFrameInsertion) :
http://e-nautia.com/vanden/disk/Publiqu ... omex2).mkv

144fps (original 48fps (Doubled) + 1 BlackFrameInsertion) :
https://e-nautia.com/vanden/disk/Publiq ... omex2).mkv

144fps (original 48fps + 2 BlackFrameInsertion) :
http://e-nautia.com/vanden/disk/Publiqu ... omex2).mkv

- On my screen "96fps (original 48fps + 1 BlackFrameInsertion)" remove completly the double-image effect ... But the brightness is divided by two and there is a little flicker (CRT).

- "144fps (original 48fps (Doubled) + 1 BlackFrameInsertion) " only 1/3 of brightness are lost and double-image effect is reduced (but visible) and there are no flicker.

- "144fps (original 48fps + 2 BlackFrameInsertion) " remove completly the double-image effect ... But the brightness is divided by 2/3 and there is a little flicker (CRT).

Note :
It's possible to completly remove the double-image effect on "original 24fps" by inserting Black Frames : 96fps (original 24fps + 2 BlackFrameInsertion @ 72Hz or original 24fps + 3 BlackFrameInsertion @ 96Hz) but flicker is unbearable !!

Good stuff!

You can use SVP (SmoothVideo) to push the 24fps to 48fps or 60fps or even 120fps, then use black frames / LightBoost / strobing to have zero-motion-blur without double image effect, and without bad flicker. (100fps and 120fps becomes CRT-motion-style with LightBoost directly, while 50fps and 60fps becomes CRT-motion-style with LightBoost + 1 black frame insertion). It works.

Check out http://www.svp-team.com/

Interpolation is sometimes controversial, but it successfully achieves a goal of zero motion blur without flicker.

You will want to aim goal at framerate == stroberate
Then that's when you get "CRT effect" without motion blur and without the multiple-image effects.
So simply raise your framerate (via interpolation) until it stops flickering, and viola!

I remember reading an article and watching a video of using frame interpolation for 30 fps console games to 60.
Found the link

http://and.intercon.ru/rtfrucvg_html_slides/

http://and.intercon.ru/releases/talks/rtfrucvg/

It's fun you tell me about SmoothVideoProject !!
Because avisynth script was given to me by a developer of SmoothVideoProject ... (and it's the same script as masterotaku).

The main problem of the interpolation of frames is artifacts ...
Noting that my PC was limited with SVP profile (in 4x mode), while 2x mode (all is by default + Decrase grid step @ by two with global refinement)
I had the idea of ​​putting SVP in 2x and add balackframe (to have a better interpolation and the same fluidity as 4x) ... but in reality the avisynth script is too greedy ! (about 30% of my dual xeon system) ... the solution would be to insert the blakframes via GPU (if it's possible ?) ...

Here is the post in question : http://www.svp-team.com/forum/viewtopic.php?id=1883
There is a comparison between :
original(24fps) --> 48fps(SVP Frame Interpolation) VS 48fps(SVP Frame Interpolation + 1 BlackFrameInsertion)

vanden wrote:the solution would be to insert the blakframes via GPU (if it's possible ?) ...

Yes, or as a separate "Black Frame Insertion App" that flickers the whole screen at 1/2 the refresh rate. Possibly an always-on-top app (black window) that rapidly alternates between transparent and opaque, running at realtime priority (Administrator-level priority), synchronized to VSYNC. The challenge is proper synchronization to VSYNC, which is something more easily done via the Direct3D API, but a developer could do some research. It could be programmable to flicker at 30Hz/40Hz/60Hz on 120hz monitors, and flicker at 24Hz/48Hz/72Hz on 144Hz monitors, at varying duty cycles (in persistence increment steps of one refresh cycle), much like the 3-UFO or 4-UFO version of http://www.testufo.com/blackframes

You'd simply run your video app in windowed mode, and run the blackframes app as a separate app. I may actually work to create a Black Frames Insertion App, but if another developer beats me to this one, I'd love to hear back.

I think for movie playback, it would be the most cinematic at 48Hz or 72Hz flicker, reasonably closely mimicking an old-fashioned film projector. It would also provide motion blur reduction for windowed 60fps games and emulators as well, also good for running on LightBoost and Turbo240 displays that aren't capable of single-strobe at 60Hz.

You'd simply run your video app in windowed mode, and run the blackframes app as a separate app. I may actually work to create a Black Frames Insertion App, but if another developer beats me to this one, I'd love to hear back.

Good News !

I think for movie playback, it would be the most cinematic at 48Hz or 72Hz flicker, reasonably closely mimicking an old-fashioned film projector. It would also provide motion blur reduction for windowed 60fps games and emulators as well, also good for running on LightBoost and Turbo240 displays that aren't capable of single-strobe at 60Hz.

To watch a video this mode is good for LCD (with no strobe) for decrease motion blur. But has no interest on LightBoost/CRT displays that haven't motion blur ... because it has no effect on double-image effect.
But it would also provide motion blur reduction for windowed 60fps games and emulators on LightBoost and Turbo240 displays that aren't capable of single-strobe at 60Hz.

My tests :
1. BFI(24-96-1Bframes) :
For 1/24 of second : Original/Original/Original/BF

2. BFI(24-96-2BframesConsecutive) :
For 1/24 of second : Original/Original/BF/BF

3. BFI(24-96-2BframesInterlaced) = Mimicking an old-fashioned film projector @ 48Hz :
For 1/24 of second : Original/BF/Original/BF

4. BFI(24-96-3Bframes) :
For 1/24 of second : Original/BF/BF/BF


On my screen only 4 remove completly double image effect ... 2 decrease double image effect and 1 also (but less). But Flickering is unacceptable.

For 3 double image effect is not really decreased, but on LCD (with no strobing) this should reduce the motion blur ... Flickering is acceptable.


5. Mimicking an old-fashioned film projector @ 72Hz is :
For 1/24 of second : Original/BF/Original/BF/Original/BF
Same as mimicking an old-fashioned film projector @ 48Hz but there are less flickering.

Very interesting experiments!
Mind if I copy/break your posts to a separate thread?

vanden wrote:To watch a video this mode is good for LCD (with no strobe) for decrease motion blur. But has no interest on LightBoost/CRT displays that haven't motion blur ... because it has no effect on double-image effect.

The double image effect disappears if you use single-strobe per frame (e.g. 1 visible frame, rest black frames), but that can be extremely flickery due to the short duty cycle. The best monitor for this experiment would probably be a BENQ Blur Reduction V2, due to its ability to single-strobe all the way from 50Hz through 144Hz.

Chief Blur Buster wrote: Mind if I copy/break your posts to a separate thread?

Yes, no problem !

What I don't get is why the motion-blur reducing effect of a strobing backlight allegedly diminishes or even disappear with lower FPS. This is not the case with CRTs, so why should it be with LCDs? The physical principle is the same - avoid the sample&hold-effect in the eye by clearing the picture
a) long enough
b) at a frequency high enough to avoid perceived flicker.

In my opinion it should not matter a lot for motion blur whether I have 120fps@120Hz refresh@120Hz backlight strobing or 40fps@120Hz refresh@120Hz BL strobing (if Vsync is disabled). It should even be possible to do a strobing backlight at 60Hz refresh rate if the time the display goes blank is not more than with 120Hz and the strobing frequency is still 120Hz - thus doing two strobes per refresh. According to PRAD.de, the Asus VG278HE shows exactly this behaviour (http://www.prad.de/new/monitore/test/20 ... #Backlight or english: http://www.prad.de/en/monitore/review/2 ... part7.html).

I accept that the picture gets more jerky with lower fps - of course. I also accept that there is a possibility for slight stuttering - but this should be less the higher the refresh rate of the display is, and only once Vsync is enabled.
Of course, this excludes variable refresh rates like with GSync - that's a whole other topic, as currently you can't get impulse backlighting and variable (=potentially low) refresh rates at the same time.

In my understanding, a LCD with strobing backlight, synced to the display's refresh rate should exactly behave like a CRT.
Yes, it may put more strain to the eye because the cycling of LEDs is faster than than with phosphor. But the physical principles are the same.

Please explain to me why it should not be possible to enjoy the benefits of reduced motion blur due to backlight strobing @ less than 120fps.

KILLI wrote:What I don't get is why the motion-blur reducing effect of a strobing backlight allegedly diminishes or even disappear with lower FPS. This is not the case with CRTs, so why should it be with LCDs?
(...snip...)
Please explain to me why it should not be possible to enjoy the benefits of reduced motion blur due to backlight strobing @ less than 120fps.

Same problem occurs with CRT
See http://www.testufo.com on CRT
Double image effect at half framerates of refresh rate
Triple image effect at third framerate of refresh rate
Quad image effect at quarter framerate of refresh rate

Even CRT 60fps@120Hz has the same problem as LightBoost!
CRT 60fps@120fps has same problem as 30fps@60Hz
Your eyes keep moving between refreshes when you track eyes on moving objects. The flickers occurs in different parts of your retina, creating the multiple image effect when frame rate is less than flicker rate. For more educational animations, see www.testufo.com/eyetracking and www.testufo.com/blackframes as well as www.testufo.com/blackframes#count=3 to understand relationship of motion blur versus persistence (length of time a frame is visible for).

For more info, please refer to http://forums.blurbusters.com/viewtopic ... =254#p2280

Chief Blur Buster wrote:LightBoost simply looks best at 120fps because it is 120Hz

Scientifically, for the ultra clear arcade-smooth-look, you want:
strobe rate (flicker rate) == frame rate == refresh rate.
This magic formula gives you the CRT style motion clarity nirvana, on any flicker/strobed display, CRT, plama, lightboost, etc.

The chief problem used to be that Lightboost behaved like a fixed frequency CRT only supporting 120hz, so you needed 120fps to achieve the nirvana. Fortunately, 2014 is solving the problem with LightBoost clones:

BENQ Z-series Blur Reduction: Can strobe down to 75Hz minimum
BENQ Z-series Blur Reduction Version 2: Can strobe down to 50Hz minimum
ULMB found in GSYNC displays: Can strobe down to 85Hz minimum
LightBoost: Already can strobe down to 100Hz minimum
EIZO Turbo240: can strobe down to 105Hz minimum

So you could play 85fps at 85hz on ULMB for the "zero motion blur" experience.

Does that apply to 30fps video as well? Do blurays and youtube videos on a crt monitor all have a double image effect? If that is the case the big transistion to lcd monitors makes a lot more sense. Or is there a way to make crt monitors more like crt tv's?