How to extract the Photo/Video component of a MVIMG?

Question

The Google Pixel 2 and probably other phones since have the capability to cover \"Motion Photos\". These are saved as MVIMG and comparatively big.

I’m looking for a way

Answer 1

The EXIF tag is useful, but the offset is with the respect to the end of the file. The mp4 file is embedded at:

[file_size-micro_video_offset, file_size)

For example:

$ exiftool -xmp:all MVIMG_123.jpg
XMP Toolkit                     : Adobe XMP Core 5.1.0-jc003
Micro Video                     : 1
Micro Video Version             : 1
Micro Video Offset              : 2107172
Micro Video Presentation Timestamp Us: 966280
$ python -c 'import os; print os.path.getsize("MVIMG_123.jpg") - 2107172'
3322791
$ dd if=MVIMG_123.jpg of=video.mp4 bs=3322791 skip=1
$ file video.mp4 
video.mp4: ISO Media, MP4 v2 [ISO 14496-14]