how to playback a 23.97fps .mkv in 50/60fps realtime?

[savvyguy]

my current setup :
e2160 @ 3ghz
GT220 1GB
madVR with CoreAVC CUDA enabled
MPC-HC

how do i play a 4.37gb .mkv file filmed in ~24fps, and play back in 50/60fps without recoding it? i know its possible cos i've seen a vanilla blu-ray player doing a dual output to 2 TVs, 1 playing back @ 24 and the other playing at 50fps. how do they do it?

i tried using ReClock, set @ 2 x 29.97fps - it merely looks like a fast-forward version, not true 60fps. besides i can't even play it in fullscreen - it just stutters. it only works in windowed mode.

then i tried 30fps +4.2%. video looks butter smooth but the audio is weird - the voices sound like chipmunks despite the syncing/timing is correct. tried PAL speeddown and still same results. ticked and unticked the audio options still the same.

[savvyguy]

add : using win7 ultimate x86.

all software versions are their latest BETAs.

when set at AUTO, it says cannot sync this CINEMA video to your hardware. please set your monitor refresh rate near to a multiple of 24hz.

but my samsung 2032MW can only be set @ 59 or 60hz. how do we go around this limitation?

[edDV]

The way 60 Hz. HDTV sets do this is with frame repeats 2x,3x,2x,3x etc. The result is 60 fps but with the motion "judder' artifact.

"120 Hz" displays allow 5x,5x,5x,5x frame repeats without judder.

[Squash]

savvyguy,
If you're talking about realtime interpolation, you might check out this thread over at guru3d:
http://forums.guru3d.com/showthread.php?t=288017

There's also a bunch of info about this over at avsforum. It's been a while since I've seen it but if you can't find it let me know.

If you want 60 fps, just interpolate 24 fps to 120 and drop every other frame (if your hardware's up to it). I've done this stuff in recodes before when goofing around, but I've never tried realtime.

edit: went to avsforum; this thread looks pretty good and is up-to-date:
http://www.avsforum.com/avs-vb/showthread.php?t=1025800

[savvyguy]

hey squash,

thanks for the help! exactly what i wanted. you have no idea how a lot of people just don't understand my question or didn't even know this type of stuff ever existed.

unfortunately, the method described on avsforum has to use ffdshow, and that's a pretty poor decoder in terms of image quality compared to madVR. any idea how i can make it work on madVR ( with or without reclock? )

thanks again!

[savvyguy]

The way 60 Hz. HDTV sets do this is with frame repeats 2x,3x,2x,3x etc. The result is 60 fps but with the motion "judder' artifact.

"120 Hz" displays allow 5x,5x,5x,5x frame repeats without judder.

i see. then is there any way i can change the refresh rate of my monitor? i remember vaguely being able to override it with rivatuner, but seems like it will damage the monitor or something along the lines..

advice ?

[Squash]

I wouldn't think ffdshow is necessary; any player that can play avisynth scripts should work. I'd try playing the script using mpchc. It allows use of madvr (View...Options...Output...madvr).

[savvyguy]

i just tried the script but everything looks the same. no interpolation happening. to double-check, i observed the cpu load - still very low so it is definitely not working on the video :S

[Squash]

I'm assuming you're using the ffdshow method. Does the "avisynth" box under "ffdshow video decoder configuration" have a checkmark next to it? Also, as I remember, you have to choose an option to install the avisynth plugin or interface or whatever they call it, when you first install ffdshow. Sorry, it's been awhile so I'm hazy on details.

[savvyguy]

hey i finally got it working! really super happy - but there are some bugs. it works pretty well on my 720p and 1080p videos, but weirdly.. when trying out a low-res .mp4 video, i tried jumping to a scene (1hour), the video just flashes at the scene when it just started.

another question i'd like to ask is : is it correct that we are sacrificing image quality when doing this? i can see quite a bit of "boxy" pixelation after using the 60fps fix, but the buttery smoothness is really getting me excited!

lastly, am i right to say that in home settings ( i.e. not a PC ), all the processing is done via the LCD TV rather than the blu-ray player, yes? just curious how it works.

thanks!

[Squash]

Good to hear.

1. Don't know about the mp4 problem. You might look at your source filter (aka splitter) for mp4. In mpchc, it's Options...Internal Filters...Source Filters. Try enabling/disabling mpchc's internal splitter via the checkbox next to it. Update your external splitter if necessary. Also on that page, do the same with the transform filter (aka decoder) for whatever video type is in the mp4 (you can drag the mp4 onto graphstudio if you don't know what your default mp4 splitter or video decoder is). There are much more knowledgeable people here who could help you with this better than I could, maybe they'll chip in.

2. Yes, there will be some quality loss, you're creating frames that did not exist before. Interpolation will create artifacts, it's in its nature. These can be minimized through refinement of the scripts, but the realtime scripts have been designed to run fast, not to maximize quality. If you really want to get into it, there are discussions on doom9 that cover it quite well. I had a script that worked very well on most material, but when I tried it on a clip that had a lot of quick fade-ins and fade-outs, it turned to crap. By playing with the various options I was able to fix this, but it ran slower. I wasn't doing it for real-time playback, though, so I didn't care.

3. Yes, if by "processing" you're referring to interpolation. I am not aware of any interpolating blu-ray players (but I could be wrong). Interpolation is a feature on many mid- to high-end TVs and is usually not found on bargain units. On my Samsung it's called "auto-motion plus"; different manufacturers have different names for it. It can be turned on or off, up or down, and it does produce artifacts, though they are pretty minor these days. I myself like it, but some people don't. There are tons of posts around the various forums about the pluses and minuses.

[jagabo]

There are many threads here at Videohelp about this too. Here are some posts with bad case examples:
https://forum.videohelp.com/threads/311770-Nero-Vision-%28edit-%29-Motion-Adaptive-Fram...=1#post1965353
https://forum.videohelp.com/threads/307226-Need-advanced-framerate-converter?p=1890385&...=1#post1890385

[edDV]

another question i'd like to ask is : is it correct that we are sacrificing image quality when doing this? i can see quite a bit of "boxy" pixelation after using the 60fps fix, but the buttery smoothness is really getting me excited!

Yes, at 60Hz the trade off is 23 judder (no interpolation artifacts) vs. smooth motion with considerable interpolation artifacts.

[edDV]

3. Yes, if by "processing" you're referring to interpolation. I am not aware of any interpolating blu-ray players (but I could be wrong). Interpolation is a feature on many mid- to high-end TVs and is usually not found on bargain units. On my Samsung it's called "auto-motion plus"; different manufacturers have different names for it. It can be turned on or off, up or down, and it does produce artifacts, though they are pretty minor these days. I myself like it, but some people don't. There are tons of posts around the various forums about the pluses and minuses.

HDTV set interpolative processing is done in 120Hz up sets (100Hz up PAL). It is not common for TV's to interpolate at 60Hz.

Default for 24p film is simple 5x frame repeats to 120 fps as explained above. Motion processing modes interpolate the 4 intermediate frames instead of repeating in an attempt to make 24p appear more motion fluid. The cost is interpolation arifacts.

Blu-Ray players output straight 24p (for HDTV sets to process) or telecine 24p to 60i (59.94i actual), or frame repeat 2x 3x to 59.94p (same as DVD players in progressive mode).

[savvyguy]

Good to hear.

1. Don't know about the mp4 problem. You might look at your source filter (aka splitter) for mp4. In mpchc, it's Options...Internal Filters...Source Filters. Try enabling/disabling mpchc's internal splitter via the checkbox next to it. Update your external splitter if necessary. Also on that page, do the same with the transform filter (aka decoder) for whatever video type is in the mp4 (you can drag the mp4 onto graphstudio if you don't know what your default mp4 splitter or video decoder is). There are much more knowledgeable people here who could help you with this better than I could, maybe they'll chip in.

2. Yes, there will be some quality loss, you're creating frames that did not exist before. Interpolation will create artifacts, it's in its nature. These can be minimized through refinement of the scripts, but the realtime scripts have been designed to run fast, not to maximize quality. If you really want to get into it, there are discussions on doom9 that cover it quite well. I had a script that worked very well on most material, but when I tried it on a clip that had a lot of quick fade-ins and fade-outs, it turned to crap. By playing with the various options I was able to fix this, but it ran slower. I wasn't doing it for real-time playback, though, so I didn't care.

3. Yes, if by "processing" you're referring to interpolation. I am not aware of any interpolating blu-ray players (but I could be wrong). Interpolation is a feature on many mid- to high-end TVs and is usually not found on bargain units. On my Samsung it's called "auto-motion plus"; different manufacturers have different names for it. It can be turned on or off, up or down, and it does produce artifacts, though they are pretty minor these days. I myself like it, but some people don't. There are tons of posts around the various forums about the pluses and minuses.

i like the smooth motion a lot, but trading it for image quality is a tough one to decide on. what i've noticed on the higher end TVs is that when it uses such stuff, it tends to "lag" at certain points - looks like frame dropping but the quality is maintained ( i went close to the demo units to see whether there was pixelation or not )

so the only keywords are "interpolation", "frame repeat" right? need that to dig out all the active threads on these topics, as well as use them to see which TVs are capable of pulling off this tech. pretty sure the salespeople in my area don't know the technical term for it.

thanks everyone again for the help! all the articles and threads have really been highly technical with a lot of jargon and tools i've never seen before. would need a long time to digest them..

[edDV]

Your problem is compounded by being in a PAL region but trying to watch at 60 fps.

I'm not as familiar with PAL TV models and the interpoation strategies they use. The "100 Hz" sets frame repeat or interpolate 25 fps PAL 4x to 100 fps. Film 24 fps material is a greater challenge. Normally PAL conversion of 24p to 25i involves a 4% speedup + audio processing to eliminate pitch shift. 100 Hz sets then process 4x to 100 fps.

Alternate PAL world strategies are to process 24p 3x to 72 fps (e.g. Pioneer Kuro) or 4x to 96 fps. This can be done with frame repeats or interpolation of intermediate frames.

If your source is a computer, the 50 Hz vs. 60 Hz issues become more complex and the internal workings of display cards is more opaque.

[jagabo]

I think I read that most of the 100Hz PAL sets also work at 96 fps. Even if they didn't, adding an extra frame repeat every 24 frames would barely be noticed. We're talking about the difference between most frames being displayed for 40 milliseconds and an occasional frame for 50 milliseconds. 60 field per second interlaced NTSC would be different. Maybe that's bobed then goes through a 2:2:1 repeats?

[edDV]

I think I read that most of the 100Hz PAL sets also work at 96 fps. Even if they didn't, adding an extra frame repeat every 24 frames would barely be noticed. We're talking about the difference between most frames being displayed for 40 milliseconds and an occasional frame for 50 milliseconds. 60 field per second interlaced NTSC would be different. Maybe that's bobed then goes through a 2:2:1 repeats?

For USA 120 Hz sets , 29.97 fps 1080i/480i is inverse telecined to 23.976p or adaptive* deinterlaced to 59.94p. 59.94p source is frame repeated or interpolated 2x to 119.88 fps. 23.976 fps is frame repeated or interpolated 5x to 119.88 fps.


* Adaptive deinterlace separates fast moving objects from low motion in the same frame using motion detection. A bob like deinterlace is applied to moving objects while still or slow moving areas get a blend or no deinterlace. This prevents flicker and resolution loss in slow moving areas of the frame**.

**Actually this description is 1980's level technology, the current HDTV processors are far more sophisticated. The level of sophistication is tied to frames of memory and hence cost.