Hello,
The case looks like that, using ffmpeg, I processed a lot of video recordings from a sport camera (Sony Action CAM AS200). On the original files there was no defect in the form of coalescence, picture jumping (especially on the details). I attach a short video that represents the problem.
Unfortunately, I do not have any original processed files. On which I used: file combination and image stabilization. I DO NOT use any compression in ffmpeg scripts. If it helps, I can give you which scripts I use.

I tried to fix the problem by ffmpeg using the command:

ffmpeg -i res_file.mp4 -c: v libx264 -crf 18 -vf fps = fps = 30 -c: a copy output.mp4
pause

Without result. I also tried to use the HandBrake program - including the option of fixed frames and thus converting the video. It also has not changed anything.

File properties with problem:

Code:
General
Complete name               : O:\07.01.2018_PC.mp4
Format                      : MPEG-4
Format profile              : Base Media
Codec ID                    : isom (isom)
File size                   : 8.14 GiB
Duration                    : 1 h 8 min
Overall bit rate mode       : Variable
Overall bit rate            : 17.1 Mb/s
Encoded date                : UTC 2018-02-05 15:29:43
Tagged date                 : UTC 2018-02-05 15:29:43

Video
ID                          : 1
Format                      : AVC
Format/Info                 : Advanced Video Codec
Format profile              : High@L4.1
Format settings             : CABAC / 4 Ref Frames
Format settings, CABAC      : Yes
Format settings, ReFrames   : 4 frames
Codec ID                    : avc1
Codec ID/Info               : Advanced Video Coding
Duration                    : 1 h 8 min
Source duration             : 1 h 8 min
Bit rate                    : 17.0 Mb/s
Maximum bit rate            : 47.6 Mb/s
Width                       : 1 920 pixels
Height                      : 1 080 pixels
Display aspect ratio        : 16:9
Frame rate mode             : Variable
Frame rate                  : 29.970 FPS
Minimum frame rate          : 21.567 FPS
Maximum frame rate          : 29.970 FPS
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 8 bits
Scan type                   : Progressive
Bits/(Pixel*Frame)          : 0.274
Stream size                 : 8.08 GiB (99%)
Source stream size          : 8.08 GiB (99%)
Writing library             : x264 core 148 r2744 b97ae06
Encoding settings           : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=18 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=abr / mbtree=1 / bitrate=17000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Tagged date                 : UTC 2018-02-05 15:33:18
Codec configuration box     : avcC

Audio
ID                          : 2
Format                      : AAC LC
Format/Info                 : Advanced Audio Codec Low Complexity
Codec ID                    : mp4a-40-2
Duration                    : 1 h 8 min
Source duration             : 1 h 8 min
Bit rate mode               : Variable
Nominal bit rate            : 128 kb/s
Maximum bit rate            : 137 kb/s
Channel(s)                  : 2 channels
Channel layout              : L R
Sampling rate               : 48.0 kHz
Frame rate                  : 46.875 FPS (1024 SPF)
Compression mode            : Lossy
Source stream size          : 62.3 MiB (1%)
Default                     : Yes
Alternate group             : 1
Tagged date                 : UTC 2018-02-05 15:33:18
And a link to the cut out sample: https://youtu.be/wHCRL0guWNA

Is there anything I can do? I have concerns that many materials from my private archive from a few years may have such a defect