Jerky video, on pans & scrolling text.

[Welsh Jester]

I have some issues with video, i also notice a similar thing in games where if i am running along side ways and looking at a building or some scenery, it will look smooth but then get the odd random very slight jerk (not pause) then continue as normal.

But for videos it is a lot more pronounced, in windows media player i can play video that looks pretty normal until it starts having camera pans or something similar then it will start stuttering quite a lot. If i play video in VLC it looks to be smoother, but not completely free of it. I've watched videos on YouTube and camera pans are terribly jerky, but if i watch the same video with my PSVita on YouTube it seems to be completely smooth.?

Not really sure what the problem is because i've had this issue before on my desktop as well as laptop now. I have noticed WMV files show the issue up more than Xvid ones for some reason, either way the jerkiness is always random?

I cannot pinpoint the issue at all. But i know there are other people who have the same issue as i saw a comment about it on a gaming site.

Anyone have any idea here?

[hello_hello]

Often it's a frame rate vs monitor refresh rate thing.
Ideally the monitor refresh rate should be an exact multiple of the frame rate. ie 25fps and 50Hz etc. For NTSC it can't be, as it uses (roughly) 24fps and 60Hz. If the refresh rate isn't an exact multiple of the frame rate, then some frames need to be repeated, or sometimes dropped. Mostly you'll only notice it when viewing slowish, smooth camera pans, as then the repeated or dropped frames can produce a type of "judder" effect when the motion should obviously be smooth.

There's other factors too, but for a start maybe you could try MPC-HC in combination with ReClock.
ReClock will adjust the frame rate of the video a little to help minimise dropped and repeated frames etc. It can't perform miracles... it can't make 24fps play perfectly smoothly when the monitor is refreshing at 60Hz, but it can make small adjustments to the playback speed according to variations in the refresh rate, or speed 23.976fps video up to 24fps etc.

I have my PC connected to my TV and use it as my media player. As I live in PAL land too, I have the PC connecting to the TV at 50Hz. I use ReClock to speed 24fps film/video up to 25fps (which is all that happens when creating PAL DVDs from film anyway) so the refresh rate is always a multiple of the frame rate (unless it's 29.970fps NTSC, but I don't watch much of that). It eliminates the dropping/repeating of frames. ReClock is a DirectShow filter so it'd probably work with WMP but I don't think it'll work with VLC. I don't really know much about WMP as I've almost never used it due to it being a horrible pile of poo. MPC-HC will let you switch renderers which might also make a difference. Probably either VMR 9 (renderless) or EVR (custom presenter) would be the ones to try.

When it comes to video games I've got nothing..... I'm not a gamer, but I guess the same principle applies.

[jagabo]

I have noticed WMV files show the issue up more than Xvid ones for some reason

WMV drops frames when encoding if the bitrate is too low for the source video. So video tends to get jerky during high action scenes. But it sounds to me like you have some background process that's hogging CPU new and then.

[Welsh Jester]

Well after watching YouTube a bit more on my Vita, it does appear to show judder there as well.

There could be something taking up resources but i've checked task manager and cannot see anything, but i notice the exact same problem on another laptop here on YouTube or for that matter any video with panning.

I've tried rendering video in 30fps and there is still judder, but apparently there isn't supposed to be since the monitor is running 60hz.. but i still get it.

if it were slight it wouldn't matter but i can see it quite a lot. Is there anything i can do or is it always just a common issue?

[DB83]

Almost all monitors are 60hz so that has nothing to do with your issue.

Can you upload a sample clip so that we can simply check if it is the encode (should not be if you see this on-line as well)

[jagabo]

I'm not sure exactly what you mean by "judder". The term usually means the uneven motion when playing 24 fps material at 60 fps. Play the 24v30v60.avi in this post:

https://forum.videohelp.com/threads/307004-Best-framerate-conversion-%28eg-23-97-to-30-...=1#post1888926

The top row shows judder. The middle row is the inherent jerkiness/flicker of 30 fps. Does the bottom row move smoothly? This is assuming you have a 60 Hz monitor. And your computer is capable of playing 60 fps material smoothly.

[hello_hello]

There could be something taking up resources but i've checked task manager and cannot see anything, but i notice the exact same problem on another laptop here on YouTube or for that matter any video with panning.

It can be one of those things you spend most of your life not noticing, but once you do you can't help but notice it.

I've tried rendering video in 30fps and there is still judder, but apparently there isn't supposed to be since the monitor is running 60hz.. but i still get it.

What do you mean exactly? Are you just referring to games there?

As well as what jagabo said, TVs/monitors don't display video in a way which exactly matches the way our eyes work, so at lower frame rates (ie 24fps) camera pans can appear not to be smooth even when the frame and refresh rates match. Motion won't appear "juddery" if they do match (it won't look like it's very quickly pausing and restarting or moving in uneven steps) but it still may not look smooth. I refer to it as "jitter" as opposed to an uneven "judder". Having a lot of contrast in an image seems to make the effect more obvious.

The little video I've attached is an example of the effect I'm referring to. It's 25fps, but even when my TV is refreshing at 50Hz, it's horrible to watch. You can pause it though and it's obvious the effect is not in the video itself, but it's caused by the way it's being displayed. I guess as the TVs and monitors we use grow larger, the more we notice this stuff.
I don't know much about games but I assume the same principle applies.

[Welsh Jester]

I've attached a video with scrolling and zooming, this is at 30fps. I know i notice like a slight ghosting or trail on things but i assume this is to do with the scroll/zoom speed. But if i watch this, sometimes there is a jitter/judder and sometimes there isn't. Either way it is random.

Here's the same video on YouTube http://www.youtube.com/watch?v=-v3I7EVYoak&feature=youtu.be the issue shows up a lot more on here for some reason.

I saw the 2 videos posted above as well and the 60fps one is definitely smooth, i am almost certain that i tried rendering at that speed before though with a slow moving object and still if you look closely can sometimes see a random jitter.

As for games it is not nearly this bad but i am talking about ones running 60fps usually, but because i am on my laptop at the minute i haven't checked enough to see what the issue is. Maybe the frame rate is dropping a bit below 60 and that can cause it, i'll have to monitor the frame rate and when it happens.

I'm currently on my laptop plugged into my monitor which is capable of 120hz. But it's at 60hz right now because of my laptop.

[jagabo]

Yes, 30p is jerky/flickery. Not quite as bad as film. If you want smoother video render at 60 fps. Or use motion blur and depth-of-field techniques as is done with 24 fps film.

[hello_hello]

I've attached a video with scrolling and zooming, this is at 30fps. I know i notice like a slight ghosting or trail on things but i assume this is to do with the scroll/zoom speed. But if i watch this, sometimes there is a jitter/judder and sometimes there isn't. Either way it is random.

I know even less about how playing video within a browser works than I do regarding playing video with a media player, which effectively means I know nothing about playing video within a broswer, but I can tell you when I ran Firefox on the TV (60Hz) and played the YouTube video you linked to, there was an unevenness to the motion which appeared to be somewhat random. When I downloaded the video from YouTube and played it with MPC-HC it was perfectly smooth. Well it still exhibited the "jitter" effect you get from low frame rates, but there was no unevenness to the motion.

I saw the 2 videos posted above as well and the 60fps one is definitely smooth, i am almost certain that i tried rendering at that speed before though with a slow moving object and still if you look closely can sometimes see a random jitter.

The most likely cause of that is a frame rate/refresh rate mismatch. If you're connected to a TV, make sure you're really connecting at 60Hz and not 59.94Hz (or whatever it is for NTSC in case I got that wrong), and/or if it's really 60Hz. According to ReClock (which I didn't use while checking the downloaded YouTube video) mine card connects to my TV at 60.003Hz or 50.002Hz. Not enough difference to cause a noticeable problem with dropped/repeated frames, but the idea of using Reclock is to adjust frame rates slightly while playing video to make up for such discrepancies. Have you tried it yet?