Madvr interfering with MBT

[A8HTPC 38]

My tv does support 24fps and most useful refresh rates (25, 50, 60, 23.967, ect...) my desktop monitor does not however which is just a testing system since its more powerful then my htpc. 

 

 

MBT runs on my main htpc connected to my tv which is the system i use.

 

Then when i play around with settings i play on my desktop install of mbt to rule out weak hardware from htpc, and to ensure its not a weak cpu/gpu causing issues for me. I also dont like tweaking and messing and playing with settings on my main htpc system as it has always resulted in headaches. 

 

Ah Sorry, must have misread that post in our convo.

Edited March 24, 2014 by A8HTPC

[spon 24]

Hi guys,

 

This really isn't a MBT question, but since refresh rates have been discussed, I was wondering if anyone could point me in the direction of an overview of how refresh rates fit into the whole HTPC equation. My TV is capable of displaying pretty much all useful refresh rates, but I've never been clear about how to set up the other components to provide the best quality picture. I'm assuming that the best scenario would be to output the native refresh rate of the video file being played, correct?

[A8HTPC 38]

I would read up on movie fps vs refresh rates and 3:2 pull down since its a long description. Most bluray movies are recorded at 24.976 fps, some DVDs I have seen at 24.970 and 29.970fps. Now FPS can be thought of in Hz. Since our default video output is 60Hz (60fps) your video card and/or TV will need to do some math to get the video to play ok. The best thing to do is to have your video refresh rate switch to 23Hz which is actually 23.976 fps, for blurays and you can leave your video at 60hz usually for DVDs and let ReClock work its magic to get the movie adjusted to play correctly on your TV at 60hz

 

If your TV does not support 24p playback, there is little gain from switching resolution. Make sure if you TV does support 24p, that it will output in multiples of 24, such as 24,48,96 etc. Some TVs will have a light flicker while watching in 24p but the motion is much smooth.

 

Also, so far only AMD Radeon video cards seem to calculate 24.976 refresh rate correctly. Other cards such as NVidia are close but not perfect. You might find some that are very very close.

[babgvant 143]

I think what's happening is that madVR's window is overlaying (it is greedy* ) the MBT window so it's not getting mouse movement events. Older versions of MBT used a low level hook to always get key/mouse events so that's probably why it wasn't an issue earlier. I've noticed that forcing MBT UI over madVR (triggering a search for e.g.) restores the mouse. So we need to figure out how to do something like that or get mouse events some other way.

 

* TBC, there are good reasons for madVR to do that.

[babgvant 143]

I would read up on movie fps vs refresh rates and 3:2 pull down since its a long description. Most bluray movies are recorded at 24.976 fps, some DVDs I have seen at 24.970 and 29.970fps. Now FPS can be thought of in Hz. Since our default video output is 60Hz (60fps) your video card and/or TV will need to do some math to get the video to play ok. The best thing to do is to have your video refresh rate switch to 23Hz which is actually 23.976 fps, for blurays and you can leave your video at 60hz usually for DVDs and let ReClock work its magic to get the movie adjusted to play correctly on your TV at 60hz

 

If your TV does not support 24p playback, there is little gain from switching resolution. Make sure if you TV does support 24p, that it will output in multiples of 24, such as 24,48,96 etc. Some TVs will have a light flicker while watching in 24p but the motion is much smooth.

 

Also, so far only AMD Radeon video cards seem to calculate 24.976 refresh rate correctly. Other cards such as NVidia are close but not perfect. You might find some that are very very close.

 

Film content is [generally*] 24 progressive frames per second (FPS) (i.e. 24p), but when you view them outside the cinema it is either stored at 24000/1001 (23.976) progressive FPS or 30000/1001 (29.97) interlaced FPS**. The 23.976p->29.97i (rendered FPS is 60000/1001 or 59.97) move is done using a process called telecine (TC) which causes frames to be repeated in a 2:3 (or 3:2) cadence which causes an effect called "judder" when viewing. Most DVD content is actually stored in 23.976, but the rendering pipeline will apply the TC "softly" by noting, and applying the repeat flags set on the decoded frame. Broadcasted film content is most often "hard" TC which means that the repeat cadence is actually represented in "physical" frames instead of just flags on the frames. Most BD content is stored at 23.976FPS and intended to be rendered at the native frame rate, but if your TV doesn't support it the same sort of soft TC process will be applied - it just isn't actually encoded into the frames.

 

TC can be undone using a process called inverse telecine (IVTC), obviously this is much easier when the content is soft-TC because it means that the renderer just ignores the flags and renders the content at the real frame rate. It is also possible to IVTC hard-TC, but the renderer has to be clever enough to scan and detect the cadence of the repeated frames and then decimate the content (i.e. drop the repeated frames).

 

In either case the right framerate to select on your HTPC for film content is 23Hz assuming your TV supports 24p input and the playback chain can apply IVTC.

 

If it cannot do IVTC but the TV supports 24p input, use 23Hz for native 24p content and 59Hz for 24p with TC applied.

 

If your TV doesn't support 24p input, leave it at 59Hz and never ask someone to show you what judder is .

 

Historically AMD has done the best job w/ 24000/1001 on the PC with their discrete GPU (integrated GPU story is more complicated), with NVIDIA next (you needed to create a custom resolution which causes some potentially undesirable consequences to get as close as AMD), with Intel last (24.000Hz really old and 23.973 since moving the GPU on die), but that isn't the case anymore. With current gen hardware Intel Haswell GPUs have the best refresh rate accuracy.

 

* 48FPS or HFR also exists but isn't relevant here because you can't get it in your house yet.

** Intentionally ignoring PAL-land issues