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

I did find https://github.com/cliveontoast/GoMoPho which scans for the mp4 header and then dumps the video.

We can do the same, scanning for ftypmp4 from the MP4 header (actual file starts 4 bytes earlier):

Thus to extract videos:

for i in MVIMG*.jpg; do \
  ofs=$(grep -F --byte-offset --only-matching --text ftypmp4 "$i"); \
  ofs=${ofs%:*}; \
  [[ $ofs ]] && dd "if=$i" "of=${i%.jpg}.mp4" bs=$((ofs-4)) skip=1; \
done

And to remove videos:

for i in MVIMG*.jpg; do \
  ofs=$(grep -F --byte-offset --only-matching --text ftypmp4 "$i"); \
  ofs=${ofs%:*}; \
  [[ $ofs ]] && truncate -s $((ofs-4)) "$i"; \
done