MotionPie and custom filenames

I wanted to setup a tiny timelapse-rig using raspberry pi and the official addon-camera.

A quick search returned MotionPie ( https://github.com/ccrisan/motionPie ), and after setting it up using the supplied wiki-pages and some initial configuration I had a feed to watch.

I plugged in a USB-drive (make sure it has a partition and a filesystem MotinoPie can read (ext4 f.ex.)) and under the admin-menu, and “File Storage” you should be able to select the external storage.

In order to create a timelapse you have to save snapshots at regular intervals, this is done under “Still Images”, select “Interval Snapshots” under “Capture Mode” and insert a interval.
Remember 30 pictures per second for a movie equalls 1800 pictures per minute of video.
Dont exagerate your interval, or you will have a very long (and boring?) timelapse.

15s interval over 3 days is 10 minutes of video and 18 000 pictures.

Now the tricky part was that I wanted to create the timelapse outside of MotionPie, and therefore I needed the pictures in sequence, and not using the default file naming.
There was no real legend with variables that I wanted (I wanted to use unix time) – so some quick googling led me to this handy site ( http://www.cyberciti.biz/faq/linux-unix-formatting-dates-for-display/ ) – and that site had this handy table:

%FORMAT String Description
%% a literal %
%a locale’s abbreviated weekday name (e.g., Sun)
%A locale’s full weekday name (e.g., Sunday)
%b locale’s abbreviated month name (e.g., Jan)
%B locale’s full month name (e.g., January)
%c locale’s date and time (e.g., Thu Mar 3 23:05:25 2005)
%C century; like %Y, except omit last two digits (e.g., 21)
%d day of month (e.g, 01)
%D date; same as %m/%d/%y
%e day of month, space padded; same as %_d
%F full date; same as %Y-%m-%d
%g last two digits of year of ISO week number (see %G)
%G year of ISO week number (see %V); normally useful only with %V
%h same as %b
%H hour (00..23)
%I hour (01..12)
%j day of year (001..366)
%k hour ( 0..23)
%l hour ( 1..12)
%m month (01..12)
%M minute (00..59)
%n a newline
%N nanoseconds (000000000..999999999)
%p locale’s equivalent of either AM or PM; blank if not known
%P like %p, but lower case
%r locale’s 12-hour clock time (e.g., 11:11:04 PM)
%R 24-hour hour and minute; same as %H:%M
%s seconds since 1970-01-01 00:00:00 UTC
%S second (00..60)
%t a tab
%T time; same as %H:%M:%S
%u day of week (1..7); 1 is Monday
%U week number of year, with Sunday as first day of week (00..53)
%V ISO week number, with Monday as first day of week (01..53)
%w day of week (0..6); 0 is Sunday
%W week number of year, with Monday as first day of week (00..53)
%x locale’s date representation (e.g., 12/31/99)
%X locale’s time representation (e.g., 23:13:48)
%y last two digits of year (00..99)
%Y year
%z +hhmm numeric timezone (e.g., -0400)
%:z +hh:mm numeric timezone (e.g., -04:00)
%::z +hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z alphabetic time zone abbreviation (e.g., EDT)

So then it was just a matter of replacing anything under “Image File Name” with “pics/%s” – and everything will be jolly good.