VSync

[J7N]

I just tested the setting in BSPlayer 1.36. I watched the first 4 minutes of "Stargate Atlantis - [01x01] - Rising" looking for smooth camera pans. Indeed the wait for vertical blank ensured there was no tearing. So I prefer it ON. In theory this makes the time between 2 successive frames irregular, but since it is already impossible to make the display refresh exactly every n-th frame (n is integer), I prefer no tearing at the cost of slightly increased jerky playback.

There is a system component available which attempts to slave the audio clock to video whenever the display refresh rate is close to an even multiple of the FPS. I tried it but didn't like the way it influenced audio playback in general. It's good maybe for a dedicated cinema PC. http://reclock.free.fr/

[Digiface]

Does this vsync also affect to secondary display (TV)?

[kimiraikkonen]

V-Sync depends on your system. Sometimes (usually) it is good to turn it ON if your system is strong enough, sometimes NO.

Computers which are strong enough to render FPS more than refresh rate of monitor may cause tearing and sync problem if V-SYNC is OFF.

I know only these but more information could be more helpful.

This also usually applies to 3d games.

[adicoto]

Refresh rates and v-sync have nothing to do. V-sync it's related to frame displaying (24-30 fps) while refresh rates usually are 75-120 Hz (1/sec)

[J7N]

Originally Posted by adicoto

Refresh rates and v-sync have nothing to do. V-sync it's related to frame displaying (24-30 fps) while refresh rates usually are 75-120 Hz (1/sec)

How do you map those 24 frames of a movie to a 85 refresh cycles of the display? You could write the current frame disregarding at which position the electron beam of the display is, or you can wait while the beam reaches the bottom of the screen and the blanking interval starts.

I've heard that M$ Direct3D always has Vsync ON, angering some gamers. But apparently BSPlayer's default renderer (overlay mixer?) is not affected.

Does this vsync also affect to secondary display (TV)?

I have no way of testing that (lack of a S-Video receiving hardware). In fact I don't even know at what rate the S-video of common video adapters works. Does it switch standards or always output PAL compatible (in this case a video that's not PAL would look very jerky)? You can easily test it yourself if you have half an hour of time.

[adicoto]

I am using it OFF by default and never had any problem on my TV (and watched some 100 movies allready on my TV-out) but never used S-video. The card does have an S-video out but in there I am using an s-video to composit adapter. So, I am waching 23,976 fps movies on a TV set that works on 50 Hz interlaced and also 59.94 fps movies on the same TV . How does it sincronize ? It does not need, as the refreshing rates for both TV and monitor, are greater than human eye perception, you can't see when the image is changing.

[Digiface]

After all, i decided to keep it ON. If the only downside is little more resources used, i can live with that. I think it's good to keep in ON, just in case.

[kimiraikkonen]

Originally Posted by adicoto

Refresh rates and v-sync have nothing to do. V-sync it's related to frame displaying (24-30 fps) while refresh rates usually are 75-120 Hz (1/sec)

Smoothness of playback such as avoiding "tearing" is related to refesh rate and FPS together if V-Sync is turned ON.

http://www.tweakguides.com/Graphics_9.html

[adicoto]

Originally Posted by kimiraikkonen

Smoothness of playback such as avoiding "tearing" is related to refesh rate and FPS together if V-Sync is turned ON.

http://www.tweakguides.com/Graphics_9.html

This article it's dedicated to how will work a graphic card into a game if using vsinc on/off. It's not related to displaying a constant framerate as when playing a video file. I am not sure about how good the article is, because you can read in the first paragraph that the electron gun it's moving inside the CRT. That's far, far away from the reality.

[J7N]

The article indeed incorrectly describes some technical details. The author also claims that the videoadapter is sending more frames to the display than the display is able to draw. In fact the monitor outputs every frame it receives unless the rate is so high that the monitor has to turn itself off as a measure of safety (usually with a graphical error message on modern displays). What the author really meant is that with V-Sync off the frame buffer (inside the videoadapter itself) may get updated multiple times during a single redraw.

How does it sincronize ? It does not need, as the refreshing rates for both TV and monitor, are greater than human eye perception

The 50 or 60 redraws per second were once chosen due to imperfect DC power sources at that time. The AC component with frequency different from the field/frame rate would produce visible flicker on the output image. [1] So these quick changes are indeed noticeable even to the human eye. There is also a perceptible difference between 25 and 50 fps material, most noticeable in quick motions that require more frames to be perceived smootly. A ready source of 50/60 fps to test are true interlaced videos, deinterlaced with Bob method.

This article it's [..] not related to displaying a constant framerate as when playing a video file.

A video game in this context is no different than a movie. Both are video sources with an arbitrary framerate that must be displayed on a fixed rate video display.

1. http://en.wikipedia.org/wiki/Televis...es_were_chosen

[kimiraikkonen]

Many pretensions/claims, but one truth :?

For 3Ds the article is pretty good i think on Wiki:
Computer games often allow vertical synchronization as an option, but is sometimes disabled because it has the effect of limiting frame rates to the monitor's refresh rate frequency.


The best answer is on Wiki i think:
http://en.wikipedia.org/wiki/V-sync

[J7N]

I also read this small article but didn't post because I wanted to quote somebody speaking exactly about movies, not "computer graphics". Though the same applies.

I agree with TweakGuides that it is not meaningful to try to draw more frames than the monitor is set up to. So having a large (and fluctuating) FPS value is not the best option.

With V-sync OFF you can get an individual pixel to appear at the moment closest to the one intended by the drawing application. With wait for V-sync ON you obviously have to wait. I suppose if you would like to observe a small part of the picture, where page tearing statistically would not happen as often, the setting would better be set off. Movies however are intended to be watched as whole frames. If you don't have a suitable movie or test clip, try to imagine a driving game where you make a sharp turn to one side. It would ruin the realism if half (in average) of the screen shows the previous angle of the car.

As the author of 100fps.com has said: The eye is not a video camera and has no frame rate. It is designed to work with continuous flow of information.

[J7N]

The Wait for vertical blank option in BSPlayer sometimes does nothing. Or shall I say, DirectShow doesn't always allow to turn vsync on.

A new version of Media Player Classic (a real video player) has recently been released. One of its goals is to adress tearing.

If VMR9 is active you can press Ctrl-T to test for or demonstrate tearing and video jitter. Other output modes could use similar pre-rendered test clip. The two red lines should appear perfectly straight. Jitter will cause them to jump an uneven distance every rendered frame. In a perfect jitterless video the bars will move across the screen smoothly.

If you fail to acknowledge that jitter and tearing is a problem, then I wonder what are you looking for in your beloved HD. At higher resolutions the timing error will span more pixels and become easier to notice.

[adicoto]

That's Media Player Classics Home Cinema and ain't a new release.

MPC can be found here

[Digiface]

Originally Posted by Digiface

Can't really say anything yet. Time will tell.

Just want to mention, that i haven't got any problems with Vsync disabled.