Parse MP4s and related video files and extract the creation timestamp
from the "mdhd" (media header) atom.
Introduce helper function templates to extract arbitrary-length
unsigned integers in big-endian format from file or memory.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
Thus, metadata has to be only read once and the picture_load_exif_data()
function can be removed.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
