Mirrored video from rear camera

Contributing and equipment
1

Hi, I don’t if no one had this problem or I can’t use a search function…
I have recordings from some navitel dashcam I video from rear camera is flipped/mirrored left-right. I think someone mounted rear camera wrong side :joy:
How to fix it not doing it file by file? One I fixed with clipchamp, but it’s not the way I would appreciate. GPS coordinates are in separate file, so this is not an issue.

2

Yes, unfortunately you will need to do this for each incorrect video file in a video editor (you can probably do a batch operation with something like ffmpeg, for example Flip Videos in Batch with These 3 Free Software)

3

Seems like Mediacoder is doing good job.
Thanks :slightly_smiling_face:

4

I’d be wary of image quality loss of a video conversion process, so this is what I would do.

  • Run video_process from mapillary_tools. This creates all the individual geotagged images.
  • mogrify -flop (mogrify is part of ImageMagick)
  • Run upload from mapillary_tools

AFAIK mogrify wont adversely affect the EXIF tags nor touch the Mapillary specific json file. If filesize etc cross-checking is done in upload though one can mapillary_tools sample_video only, which creates the images with a creation date/time stamp only. Then run process_and_upload after the mogrify step.

Only real downside is that if you currently upload videos only, then the total upload size will approx double.