'Jerky' movement of transport items in finished edit.

raoul-beaman wrote on 3/14/2019, 11:37 AM

Morning everyone. I apologise if I ask the most basic of questions in relation to Magix video editing but I need some help that no one locally seems to be able to answer. I have just upgraded to Magix Movie Edit Pro Premium and work on a Cyberpower Ryzen Ammunition tower with an 8 core AMD Ryzen 7.1700 processor, and have just upgraded the graphics card from a Nvidia GeForce GTX 1070 8GB to a GeForce RTX 2080 Dual 8GB presenting to Asus screens at 1920 x 1080 resolution and a 4K screen with 3840 x 2160 Res., using high speed HDMI cables throughout. I am making a documentary on the local transport scene involving cars/trains/buses/coaches etc, so as can be appreciated, a lot of movement of items across the screen and away from the camera position. I am using 2 year old HD footage recorded originally onto SD card and then saved to Magix, and am now filming 4K footage recorded onto SDXC cards through a Sony AX 100 4K camera, again the SDXC footage then transferred to Magix for editing work. 4K footage is stunning in quality. My problem is the disappointment I have in viewing the edited footage in my test pieces, once mixing down has taken place and the finished edit has been saved as a video file (not uploaded to a device at this stage just to keep it simple.) Here lies the problem. Upon playback, the movement of any object such a train moving away from camera is 'jerky' not smooth, until far enough away to blend in to normal movement. I have tried a variety of different camera settings as well on the AX100 but cannot find the answer anywhere to solve this. In 'creating project', the movie settings are set for HD footage or 4K which ever I'm editing, and before mixing down, selecting HD2 quality and formatting in MPEG4, Magix does a good job in returning the proxy files in super quality except for this movement problem. As you can appreciate, with the main subject being movement of transport, I need to find an answer. Is my equipment not up to the mark, although on advice and investigation initially, most people said it was a good set up, OR have I got to put up with the problem which will drive me to destraction. I may even have to consider another editing software package. Magix is good for what I need/want but apologies if this is a basic problem that I have overlooked carelessly. One final point as you would expect, playing directly from camera to screens - absolutely 100% non jerky movement - so it does seem that the problem lies with the software or equipment. I have been told recently that if I upload the finished edit to a Blu-ray disc, movement would be better? I have checked the Forum and PDF manual but no comment is made. Any help gratefully appreciated. RB Herefordshire.

,.,

Comments

CubeAce wrote on 3/14/2019, 4:54 PM

@raoul-beaman

I have noticed the same thing happening on slow pans on occasion. Sometimes it is the video player that seems to be the trouble. Are you using the VLC media player, as that seems to give the smoothest playback on my system?

Also when encoding to MPEG4, I have personally found selecting 'Best' in the advanced settings also seems to reduce this problem. The HEVC codec is even slightly better in use for this to my eye.

I don't know if your setup is the cause or not as it is a high-end system but MEP is set up to take the most advantage of Intel chips. That may only make a difference to rendering time though. I'm sure John EB will know.

ericlnz wrote on 3/14/2019, 5:28 PM

Could it be that your 4K is recording 25p not 50p? To my eyes/brain 25p gives jerky movement like you are describing whereas 50 fps gives smooth movement. For years we've (in PAL countries) been recording 50i or 50p but now 4K cameras are on the market but they only shoot 25p!!! To me it's a backward step. Looking at your camera specs it appears 4K only does 25p. So if you want smooth movement you need to shoot at 1080 50p.

CubeAce wrote on 3/14/2019, 5:59 PM

@ericlnz

Both my cameras (different makes) shoot 4k at 24/25/30/48/50/and60fps. Exposure times of the frames make more difference to perceived smooth playback in most scenarios when recording in my experience. A short exposure time at 60fps can give a strobing effect with high-speed movement such as watching a drummer at full pelt seeing the drumstick at several points at the same time, which can be just as weird to look at as backward spinning wagon wheels were in old film westerns using 24fps. It's a tricky thing getting it right and not always avoidable unless planned.

ericlnz wrote on 3/14/2019, 6:38 PM

@CubeAce Maybe it's just the Panasonic consumer range, which several of my video group friends have, which only does 25p at 4K. Plus raoul-beaman's as my reading of his Sony camera's specs is that 4K is only 25p.

CubeAce wrote on 3/15/2019, 3:08 AM

@ericlnz

Hi Eric.

My point was that there can be problems with any frame rate when recording and ways around avioding it from happening up to a point because both the exposure time of a frame combined with the speed of the action, whether panning or tracking movement plays a part. Then there is the problem of hard drives that have to have the capacity to transfer the data fast enough with enough memory cashe to be read back smoothly on playback. Western Digital Black or Gold drives or similar are quite good for that.

johnebaker wrote on 3/15/2019, 3:17 PM

@raoul-beaman, @ericlnz, @CubeAce

This issue of 'jerkiness' is one of the downsides of using Progressive scan video, irrespective of the recording framerate, jerkiness will appear depending on the fps/speed ratio of the moving objects and is directly proportional to the frame rate and speed of the object, eg if the framerate is 25 fps and jerkiness appears when an object is moving at say 5 m/s then at 50 fps the object has to move twice as fast ie 10 m/s for the jerkiness to appear.

The first adjustment, as has been advised, is to record at a higher framerate, this is OK if the object is moving at a rate below where the jerkiness will appear for the higher framerate.

The second adjustment, also correctly advised, is to reduce the shutter speed to induce a degree of blur recorded in the movement of the object.

In many ways you are caught between a rock and a hard place depending on the recording capabilities of the camera and the required output format and playing device capabilities.

For the Sony AX100 your options are:

Continue to record 4K 25fps Progessive and accept the issue, minimising jerkiness by tracking the object as it move across your path - a blurred background will be reduce the apparent jerkiness and look better than the object moving across the view of a static camera.
Switch to Full HD Progressive recording and up the recording framerate to 50 fps or higher.
Switch to Full HD AVCHD Interleaved recording format if the end product playing devices can handle interleaved AVCHD video.

* For Blu-Ray because the BD specification does not support 4K, options 2 or 3 are the best to use.

BD players/Full HD/4K TV's can handle both Progressive and Interleaved video, however you must not transform Progressive to Interleave or vice versa.

You must maintain the same scan method from start to finish ie if you record progressive the you must set the BD rendering so that the video format is Progressive, like wise with Interleave to Interleave.

HTH

John EB

raoul-beaman wrote on 3/16/2019, 11:51 AM

Apologies for delay in response. Work commitments

Many thanks to CubeAce, ericInz and JohnEB for informative and helpful comment.

Re CubeAce - Thanks - Yes, using VLC for playback - already recommended, but hadn't thought of trying the HEVC Codec. Will try and see if improvement. Can I ask what two cameras you are using so I can research?

Re ericInz - Thanks also. Yes having to record at 25FPS - You echo JEB's comment re changing to HD @ 1080/50 FPS. Will try that also. Had avoided that so as not to loose the 4K quality but appreciate that I cannot have everything. Don't think I can uprate the FPS above 25 in the AX100 when filming in 4K. Also take the point re capabilities of the hard drives.

Re JohnEB. Thank you John for a most helpful and informative reply which really does put every thing into perspective. Have got to think long and hard now as to which way I go and what I am prepared to put up with and what I'm not! I just needed a response and explanation such as yours, to push me into a corner and understand that there are limitations to everything. Will digest and experiment with the suggestions given. I note the options re continuing with the AX100, also your comment re the Blu-Ray suggestion passed to me by a contact.

With the helpful comments from yourself, CubeAce and ericInz, I think I can do nothing else but flag this as 'Resolved'.Thanks again to all three of you.

CubeAce wrote on 3/16/2019, 4:45 PM

@raoul-beaman

I have been using a Nikon D500 DSLR with equally expensive Nikkor constant aperture zoom lenses. Nice output but not without it's problems as it's primarily for my stills work. The inbuilt stereo amp is quite good with an external mic but I have to keep an eye on the sound levels. Most recently I acquired the amazing little Dji Osmo Pocket which is really designed for blogging but gives amazing quality output if you don't mind a fixed focal length lens and aperture and a mono audio output. It can take an external mic but it really negates the point of using it. Being a gimble mounted design, it's really stable on the move and very lightweight. It really does fit in my pocket. So I use the D500 for tripod and zoom lens work and have the Osmo pocket for wandering around, interviews, and where I don't need to be stared at while filming in crowds. Because it's relatively new, few people realise what it is, so ignore its presence. For what it costs and what I use it for, I find it invaluable. The main problem with the Osmo Pocket is you need one of the Dji sanctioned smartphones to first activate it and then access its pro features. I don't have one of the officially sanctioned phones but my phone does meet the operating specification requirements and works okay with it.

The problem remains that you can't really mix and match frame rates within one project. It's much better to work out what exposure times you need, the same as for stills photography but work out how much movement within a frame is required to get a smooth looking playback for a given bit of action. Something I don't always get correct myself but I'm getting better at it. ND filters can be useful in that respect when needing slower exposure times when in very bright daylight.

I think John may have the correct answer though, you may be trying to mix Progressive with Interleaved clips. I would check that first as you state the individual clips themselves play OK.

That can be done by downloading the free program, MediaInfo and right-clicking any clip and selecting MediaInfo.

When opened, go to the tree view to see the parameters of your video clips.

raoul-beaman wrote on 3/17/2019, 11:18 AM

CubeAce. Hello Mate! Sorry no name to call you! Many thanks for your camera info. and interesting operational stuff. I'll look at this with interest. I also note your comments re exposure times and ND filters which I do use. Will call up MediaInfo and check what that's about. Thanks again for helpful comments - Raoul B

CubeAce wrote on 3/17/2019, 2:36 PM

@raoul-beaman

It's Ray. ☺️

The guys here are very knowledgable and pretty helpful. I hadn't heard of MediaInfo until I came to this site. It's quite useful for looking up old clip info for fitting into new projects.