Problems with shimmering of objects during turns in rendered 3D video

John-Atwell wrote on 2/25/2020, 2:52 PM

I am trying to make 3D videos using the cameras of two Samsung Galaxy S8 phones to make the left/right videos and Magix Movie Editor Pro 2015 Plus to produce the final 3D AVI video. The cameras on the phones are set to 16:9 format and resolution of 1920x1080 at 30 fps. I built a special rig to hold the cameras level with the lenses 7 cm. apart. The final video is a 3D Side by Side Video with the same resolution, that I load into one of the cell phones to view in a VR headset. When I watch the video everything looks great until I make turns, then the edges of objects seems to shimmer until I stop turning, then everything looks great again. I have tried filming at 60 fps and there is less shimmering but still there. Also tried rendering using different formats. Anyone have any ideas of a solution to my problem.

Comments

johnebaker wrote on 2/25/2020, 3:09 PM

@John-Atwell

This is a common problem when 2 cameras in that the frames are out of sync with each other. Movement from one camera is not consistent, frame by frame to the other.

Movie Edit Pro only allows video to be moved in one frame increments.

You could try the following:

Starting with a new project, increasing the project frame rate to 120 fps, and import the videos, however do not change the project settings to the match movie when asked.
Turn on Interpolate intermediate images in the Video Effects, Speed effect
Syncing the frames using the audio waveform if possible and do a test export with the framerate at 60fps to see if this helps.

IMHO opinion, if you are going to do 3D video regularly then, for a permanent fix, get a 3D camera.

HTH

John EB

RogerGunkel wrote on 2/26/2020, 7:17 AM

Just to add to what John said, with a pair of unlinked cameras, the best you are likely to achieve is about half a frame accuracy in the software. This is because the camera shutters are not synchronised together and drift may lead to an even bigger difference. At 30fps that will mean at least 1/60th second difference which will not be noticeable on non moving shots, but will probably lead to the shimmering that you are seeing on movement.

For serious 3d video filming, you either need two cameras that can be data linked, or a 3d camera as John said. For my own 3d filming, I use a JVC GS TD1 for higher quality, and a Fuji W3 for fun. I also have a Panasonic HD 750 with a 3d adapter for closeup filming.

Roger

johnebaker wrote on 2/26/2020, 7:32 AM

@John-Atwell

@RogerGunkel just reminded me - I forgot to mention in my previous post - the devices you are using must record at constant frame rate, if they produce video with variable framerate - many mobile devices do - it makes maintaining sync very difficult to almost impossible.

John EB

John-Atwell wrote on 2/27/2020, 5:38 AM

Thanks for your comments. Believe you have hit my problem with the shimmering during turns. Had a Fujifilm W3 for filming 3D for several years but wanted better quality video. New 3D cameras are above my budget for now so will have to live with the limitations of what I got. Did invest in a remote Bluetooth shutter for my cell phones so that I can better start both cameras at the same time. One thing I did notice and was curious about. When I load videos from my cell phones into the Magix software the frame rate shows 29.97fps instead of 30fps and shows 59.97fps instead of 60fps. Wonder how this affects me.

John

johnebaker wrote on 2/27/2020, 7:49 AM

@John-Atwell

. . . . Did invest in a remote Bluetooth shutter for my cell phones so that I can better start both cameras at the same time. . . . .

Unfortunately that would not help with the syncing of the shutters - when 2 cameras are linked for shutter syncing, they effectively become the 'master' / 'slave' - the master telling the slave when to open its shutter so the image is taken at the same time. Without this frame rate drift will cause issues.

. . . . Magix software the frame rate shows 29.97fps instead of 30fps and shows 59.97fps instead of 60fps . . . .

29.97 and 59.97 are the standard NTSC framerates and are often rounded to the nearest whole number when manufacturers quote a framerate in their specs.

A MediaInfo analysis of the source video will tell us exactly what you are getting - post the results from the Text view in MediaInfo.

HTH

John EB

John-Atwell wrote on 2/27/2020, 8:34 AM

Found a program through research called Handshake that will convert variable framerate videos to constant framerate videos and using it helped take away some of the shimmering during pans. Noticed that the converted videos using this software had a slightly different length than the original. This could still be causing problems. Will need to experiment more.

emmrecs wrote on 2/27/2020, 9:43 AM

@John-Atwell

Found a program through research called Handshake

I suspect you mean "Handbrake"? It is a useful program but, as @johnebaker has pointed out, the fact that your two cameras are not synced together has the potential to inevitably create the effects you are seeing.

As to the difference in overall video length, this could easily be the result of the fact your originals were variable frame-rate. How large is the overall length difference?

Jeff

John-Atwell wrote on 2/27/2020, 12:51 PM

You are right. My misspell. Difference is not much and forgot videos were not started at the same time.