Function heif_context_debug_dump_boxes_to_file 

pub unsafe extern "C" fn heif_context_debug_dump_boxes_to_file(
    ctx: *mut heif_context,
    fd: c_int,
)

Print information about the boxes of a HEIF file to file descriptor. This is for debugging and informational purposes only. You should not rely on the output having a specific format. At best, you should not use this at all.