[MPlayer-users] Forcing other framerates

[meino.cramer at gmx.de]

"Ing. Daniel Rozsnyó" <daniel at rozsnyo.com> [10-04-26 19:40]:
> Rolf Ernst wrote:
> >On 4/26/2010 10:59 AM, meino.cramer at gmx.de wrote:
> >>"Ing. Daniel Rozsnyó"<daniel at rozsnyo.com>  [10-04-26 17:21]:
> >>  
> >>>meino.cramer at gmx.de wrote:
> >>>    
> >>>>RC<cooleyr at gmail.com>  [10-04-25 20:00]:
> >>>>      
> >>>>>On Sat, 24 Apr 2010 16:32:40 +0200
> >>>>>meino.cramer at gmx.de wrote:
> >>>>>
> >>>>>        
> >>>>>>I bought a new LCD monitor with 60Hz framerate.
> >>>>>>When playing videos sometimes I git a distortet
> >>>>>>screen (not only with mplayer!!!). I think, it
> >>>>>>is because the video plays at 50Hz framerate
> >>>>>>which then interferes with the 60Hz refresh rate
> >>>>>>of the monitor.
> >>>>>>           
> >>>>>LCDs effectively do not have a refresh rate (or a "framerate").
> >>>>>         
> >>>LCD has a refresh rate! It refreshes the picture from top to bottom,
> >>>just the "memory effect" of the screen is much bigger than on CRT. 
> >>>The
> >>>LCD is effectively a visible dynamic memory (DRAM).
> >>>     
> >>   That means...?
> >>   Displaying Image contents with a rate of 25Hz to a technology
> >>   drawing every 1/60 second a picture...gives...?
> >>
> >>  
> >>>    
> >>>>>You've not described what this "distortet screen" problem is, so
> >>>>>nobody
> >>>>>can possibly help.
> >>>>>
> >>>>>
> >>>>>-- 
> >>>>>Ha. I'm the idiot.
> >>>>>_______________________________________________
> >>>>>MPlayer-users mailing list
> >>>>>MPlayer-users at mplayerhq.hu
> >>>>>https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
> >>>>>
> >>>>>         
> >>>>If LCDs have no framerate or refresh rate, they will not draw
> >>>>frames from top to bottom? How then?
> >>>>A try for a better explanation:
> >>>>Certain videos (for example the Neo<->Smith fight sceen in Matrix
> >>>>Revoluitions) with fast changing lightning conditions expose some
> >>>>screen distortions.
> >>>>They are of two kind:
> >>>>The upper half of the screen is still in "bright condition"
> >>>>when the lower half is in "dark condition" -- what comes first and
> >>>>where this "break" is, depends. Also varying is the position
> >>>>of this "break" on the screen.
> >>>>       
> >>>That is a missing vertical synchronization - what -vo are you using? 
> >>>On
> >>>what video card and which drivers? Usually on dualhead the vsync is
> >>>hard to get..
> >>>     
> >>   Oh, oh...some mails ago I got a hint to disable all VSYNCs in the
> >>   nvidia settings...
> >>
> >>   So...using -vo xv gives me the fastest (read: normal speed) video
> >>   with audio and video in sync.
> >>   Other drivers result in the message that my two core 3800+ AMD
> >>   CPU is to slow....(?)
> >>   My graühics card is ai
> >>   nVidia Corporation G73 [GeForce 7600 GT] (rev a2) which run with
> >>   the current nvidia drivers on a Linux box.
> >>   I myself and my computer each uses only one head ;)
> >>   Most of the time I use my own... ;) ;)
> >>   I disabled AutoTwinDevice in the Xorg.conf as I did with
> >>   TwindDevice (dont remember the correct names of that parameters, 
> >>but
> >>   was something like that.).
> >>
> >>   Since 60Hz is common for LCD I am asking myself, whether I am the
> >>   only one having problems with playing 25Hz/region 2 contents...?!
> >>
> >>   Since it also happens for example with the fight scene Neo<->Agent
> >>   Smith in Matrix Revolutions (DVD, region 2) I think, it is not
> >>   a bug in the video itsself....
> >>
> >>   I am a little (read: very) frustrated, since this monitor is new
> >>   and I like its colors and features, but...
> >>
> >>   So any help to circumvent this problem is *very* appreciated! :O)
> >>
> >>   Have a flicker-free evening! :O))
> >>   Best regards,
> >>   mcc
> >>
> >>-------
> >>   
> >Somewhere along this thread someone stated that the LCD is refreshed 
> >bottom to top. This is simply not true (suggest 
> >http://en.wikipedia.org/wiki/Refresh_rate). The actual 'flicker' is 
> >around 200Hz which I doubt comes into play in this case.
> >Let me reiterate that I do what you are doing often and do not observe 
> >this symptom. Maybe it is some sort of interaction between graphics 
> >card and monitor?
> 
> The problem is just VSYNC (which requires at least double buffering).
> It is often visible from a fullscreen flash video..
> 
> Back to the LCD question. The screen is refreshed at 60 or 72 or 75 Hz 
> (newer models with 3D support at 120Hz). From top to bottom, believe me 
> or not. But the afterglow is significantly longer than of CRT (which 
> has about 1/3 to 2/3 of vertical time at 60 Hz), LCD has about 0.1 to 1 
> second, which is MORE than one frame (at 60Hz so you do not see it 
> flickering).
> 
> If you are looking at 2 frames at one time, it means, that the computer 
> switches the frame in middle of screen refresh = VSYNC problem.
> 
> If VSYNC is missing, the screen refresh and movie framerate can be any 
> number, different or same, does not matter. Without proper vsync and 
> double/triple buffering you will get always a cut frame.
> 
> As the OP mentioned, it is very visible at dark+bright scene change 
> (e.g. a lightning, of photo flash, or anything similar) where you 
> clearly see two frames - half of old, half of new. Fix VSYNC.
> 
> PS. The wikipedia is not correct about CCFL, it runs at tens of kHz 
> frequencies, not 200. I work with both CCFL and LCD, so I can tell.. 
> don't believe everything you read.
> 
> PS2: There are some LCD's which really flicker - to gain low delay, 
> they shut off CCFL while the image is changing - so you do not see the 
> transition, but a crisp image. But it is bad, since it flickers :)
> 
> Daniel
> _______________________________________________
> MPlayer-users mailing list
> MPlayer-users at mplayerhq.hu
> https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
> 

So, finally it seems to be fixed now...may be "over fixed"...
Somewhere someone stated that VSYNC would be the root of all evil
so I switched it completly off.
Also I watched, that when switch ed on, all seems to become even
worse.
That was before the hint to include 
 Option         "DynamicTwinView" "FALSE"
into the screen section of my xorg.conf.
Otherwise xrandr reports wrong refresh rates.
Now: With the correct refresh rates reported by xrandr AND Vsync
the problem seems to be part of yesterday.

Final question:
If a LCD refreshes at 60Hz AND a video offers every 1/25 second
a new image (region 2 land) AND Vsync (tries to) sync both: How
could they find together? Will the LCD refresh rate be slowed down?

Really final question:
I switched on anything in the nvidia-settings, which looks like
having something to do with VSync:
XServer Xvideo settings           : Sync to VBlkank [on]
Video Blitter Adaptor settings    : Sync to VBlkank [on]
Sync to display device: HP LP2475w: [on]
Performance                       : Synv to VBlank [on]
ALlow flipping                    : [on]

Is the magic included in all of them or a part? And what part if so?

After all I am happy with my new display in the double sense of these
words. ;)

And I thank all of you for your patience and help -- especially because this
problem was by no means a problem of mplayer!

Long live the internet! Long live the Matrix...or better: What we will
build from it! ;)

Best regards,
mcc


-- 
Please don't send me any Word- or Powerpoint-Attachments
unless it's absolutely neccessary. - Send simply Text.
See http://www.gnu.org/philosophy/no-word-attachments.html
In a world without fences and walls nobody needs gates and windows.