Automatic Refreshrate Changer (2 Viewers)

[kkendall]

I think most people will agree that taking a sandwich and cutting it into four pieces won't give you four sandwiches

Even worse, it gives you a broken up sandwich with stuff dropping out on all sides

 

[Radioman]

Hidden Cinema 24Hz support on TV

So I finally also got this working, but it took some fiddling

First it didn't happen anything more then the notify popup. No refreshrate change.
I then read that I should populate the custom settings in the Nvidia Control panel with the settings my TV support.
I did and then it started to blank the screen and changed something but ... it didn't work anyhow, or I got black screen and no movie was playing (trying 24hz).

Then I did batch files with the string for Nvidia Grahics (example on the first page of this thread) and put the path in the actions row. Now it work as it should and I'm really happy with this function.

I have some questions though:
Is the API call from inside MP very different from the command string I now have in the batchfile? Even if it works now it would be great to have a technical explenation what is going on and why this is a PITA to get working for many people.
F.e. Why should the two major graphic processor company choose to have the dreaded device reset to change the refresh rate when it's not needed? Powerstrip and 12noon doesn't need it and it always work, no?

Now to the strange part in my research in this matter, and an interresting one:
I thought my Panasonic TH42PX80 plasma wasn't able to play 24Hz Cinema because I can't choose it in the Nvidia Panel and the users manual only says 50hz and 60hz.
I have lately discovered, when fiddling with Eventghost, that there was a setting of the refreshrate to 24hz. I tried and it worked and from now on the Starship Enterprise runs without judder on my Startrek Voyager movies.
I have now also read from a review om my TV that it plays Cinema movies well. Strange that the users manual doesn't tell me anything about it. Is this common?

How does the TV refresh when you use 24hz? It must be some multiple higher refresh rate on the screen to not have flicker, right?
Can anyone explain how the plasma screen is updated when it plays 24i and when it plays 24p? Can a screen refresh interlaced when the program source is progressive?

Many questions but I think some of them is of interrest for a few more then me.

 

[Radioman]

I maybe write to long messages so that no one bother reading them ...
In the meantime...

Using 24 pictures per second is just not enough to get smooth pans, this is why directors and cinematographs spends years learning how to place objcts in panning-scenes.

Confirmed in this great article
The Big Judder Problem and the Overhyping of 24p

TV's like Panasonic that displays 24p as 96p is just quadrupling the image, showing the same frame 4 times.

It's still 24hz film, right. The quadrupling is for the screen to not flicker, right? I guess you meant that some system interpolates. Thats another thing and how do I know if it does?
Anyway, I would like to know the source where you can read such in depth specifications on the Panasonics models. Thats one of my Q above.

I think most people will agree that taking a sandwich and cutting it into four pieces won't give you four sandwiches

They could be four small delicious ones though

 

[Radioman]

Don't change resolution, ONLY refreshrate !

Hello
I'll continue my monologue
This one is a new discovery that someone else may have luck to test.

I like my screen at 1280x720 when I'm on the desktop outside MP.
Inside MP I thought it would also be enough with that resolution because my Panasonic isn't Full HD anyway (just HD ready to show 1080p)
I then discovered that I can only have 1080p as resolution to be able to choose 24hz.

So when I trimmed my batchfiles with different resolutions and refreshrate, I got black screen with no movie and was switched back to the film menu in two seconds again. I have to use 1080p for all refreshrates as the only resolution, to get 24Hz to work and in consequence 50 and 60Hz.

Testing, testing ... and finally, when I also use devise reset in MP configuration, I don't need the batchfiles anymore

I think the small guidance in the first post of this thread lacks this information. It's easy to miss this and give up. To many variables and to little documentation.

epilogue:
When I want my desktop at lower res., outside MP, I use my remote which I now have setup a button to toggle the resolutions with EventGhost.

Hope this helped someone

 

[Scythe42]

How does the TV refresh when you use 24hz? It must be some multiple higher refresh rate on the screen to not have flicker, right?

Flickering only exists on CRT TVs where a cathode ray lights the pixels. Because of phospor decay CRTs need to constantly refresh the picture. Liquid crystals stay in their same state until instructed to change their state, they do not fade and therefore no refresh is required.

Plasmas are similar. Even though the technology is different, each pixel is lighted by its own mechanism.

On LCDs if the source is 24Hz, the screen changes the picture every 1/24 of a second. No classical refresh involved. What input signal the TV can handle depends on the video processor inside them. What is more important for an LCD is the reaction time. The time a display needs to change one picture to another. With LCDs having 10ms or more you will see some kind of motion blur on fast moving scenes. Usually displays these days have around 5ms making motion blur a non-issue.

Can anyone explain how the plasma screen is updated when it plays 24i and when it plays 24p? Can a screen refresh interlaced when the program source is progressive?

If the video processor of a progressive display (anything that's not a CRT) detects an interlaced source it deinterlaces it. Quality depends on the video processor itself.

In your example it displays 24fps in both cases assuming the video processor can handle 24fps, where for interlaced sources deinterlacing is done first. In addition in both cases the picture is scaled to the display's native resolution. Again the quality depends on the TV's video processor.

 

[edterbak]

Hey.. someone read your monologue?? ghehe..

You are right in saying that resolution changing is not working ok (for some people). It has been mentioned in the forum here and there, but I wasnt aware it was not in the first post. Should be there indeed. I'll PM Gibman about it.
Mediaportal can change the refreshrate by default. It is using the windows API itself for that.

I just thought of using a seperate bat or cmd file to start up MediaPortal. Put this command on the desktop or maybe also in the START > Programm> Startup - folder.

In this batch file, I use the command:
---------------
Resolution Changing Command 1 (to 1920x1080)
c:\
cd\
cd program files
cd Team... etc
Start /W MediaPortal.exe
Resolution Changing Command 2 (to preffered destop resolution)
---------------


This "Start /W" will call mediaportal.exe and wait till it terminates. If so, it will contiue and change the resolution back again. Maybe someone finds this usefull.

@ Scythe42: I think with flicker he means Judder. Otherwise it doesnt make sense.

 

[kenwonders]

I just want to report back that the latest SVN has more fixes for the refresh rate changer. I can see there is now a drop down menu for the default setting. It seems to be working perfectly now, no more blue screens as it appears to always be running the specified batch file. I'm pretty sure there was a bug in 1.1.0 alpha that meant it was often using the win32 call even if you had specified a batch file.

 

[Radioman]

Hey.. someone read your monologue?? ghehe..

He he, at least someone smiling

---------------
Resolution Changing Command 1 (to 1920x1080)
c:\
cd\
cd program files
cd Team... etc
Start /W MediaPortal.exe
Resolution Changing Command 2 (to preffered destop resolution)
---------------


This "Start /W" will call mediaportal.exe and wait till it terminates. If so, it will contiue and change the resolution back again. Maybe someone finds this usefull.

Thats another sollution. Good old batchfiles.

@ Scythe42: I think with flicker he means Judder. Otherwise it doesn't make sense.

No, I meant flicker and yes, I refered to old CRT's. I just wonder why a TV set would repeat the drawing of the screen four times/picture of the film frequency if it wasn't for flicker reducing from the screen. I mean the 24Hz movie judder would still be there if the processor doesn't put movements of the object in between. If it's not needed more then 24 drawings per second on a Plasma to reduce flicker then it's still more puzzling (see philehave above)

Thanks for reading

// Ove

 

[pilehave]

I read it too

I actually think that the 50i signal my STB sends to my plasma (through SCART) looks more fluid than the 25p MediaPortal sends, has anyone here had the same experience? Unfortunaltely my TV won't accept 50i unless I use 1280x720 that gives me awfull underscan and really bad colors. So much for spending half a months salary on a TV

 

[Scythe42]

No, I meant flicker and yes, I refered to old CRT's. I just wonder why a TV set would repeat the drawing of the screen four times/picture of the film frequency if it wasn't for flicker reducing from the screen.

This is a common misconception caused by the "a 120Hz LCD is cool because it can really display 24p because 120 is a multiple of 24" you read on the net. This is a result of markeing trying to sell complicated things to Average Joe without really understanding them. This is how the LCD TV refresh rate myth was born.

Once they sold 24p to customers they focussed on the natural 24p judder and introduced frame interpolation. What do they use again to market it? Yep, higher refresh. And because the frame interpolation implementation was subpar before, it's now 240Hz they sell as "better". And yes, the panel itself still is a 5ms panel.

I mean the 24Hz movie judder would still be there if the processor doesn't put movements of the object in between.

24fps always has some judder (not the same as NTSC judder though), because there is only that frames to display. But it's not really judder, it's just that fast movement looks jumpy but it's always constant.

Usually people see this because they are not used to watching something on a "non-flickering" display. On a CRT between the frames the brain interpolates stuff. This is why CRTs appear to be smoother in fast movement scenes. In digitial cinema projection they instert black frames between the real frames to simulate classic projection technique. Various manufactures have introduced similar stuff so simulate a more CRT like presentation but they don't really work well.

Current frame interpolation usually introduces motion artificats and sometimes can't handle a scene well and make it look jumpy like you play a few frames at two times the speed.

But the worst thing is when dealing with close up of people. Erradic movement like eye movement, blinking just feels wrong. It's hard to explain but if you analyze frame by frame you see why. It's casued by motion artifacts. Our brain is very good when dealing with facial expressions. This is why the motion artificats really ruin things here.

Frame interpolation looks awesome on some slower landscape pans though. It works great with sports as well.