There is, somewhat to my surprise, a standard for digital camera directory and file names, although it looks rather ad hoc and ex post facto to me, and the Cycliq Fly6 camera follows it to the, ah, letter.

In their implementation, we have nnnymmdd, where:

• nnn = a unique, but not necessarily sequential, number
• y = last digit of year
• mm = month
• dd = day

That produces these entries in my NAS hard drive full of bicycle action camera “footage”:

ll /mnt/video/Fly6/DCIM/
total 0
drwxr-xr-x 2 ed root 0 2015-12-10 14:18 10051210
drwxr-xr-x 2 ed root 0 2015-12-21 12:47 10051221
drwxr-xr-x 2 ed root 0 2015-12-24 20:26 10151224
drwxr-xr-x 2 ed root 0 2015-12-25 14:42 10251225
drwxr-xr-x 2 ed root 0 2015-12-26 15:26 10351226
drwxr-xr-x 2 ed root 0 2015-12-31 16:37 10451231
drwxr-xr-x 2 ed root 0 2016-01-16 16:56 10560115
drwxr-xr-x 2 ed root 0 2016-01-16 16:56 10660116
drwxr-xr-x 2 ed root 0 2016-01-31 13:28 10760131
drwxr-xr-x 2 ed root 0 2016-02-04 12:59 10860204
drwxr-xr-x 2 ed root 0 2016-02-07 17:05 10960207
drwxr-xr-x 2 ed root 0 2016-02-20 13:08 11060220
drwxr-xr-x 2 ed root 0 2016-02-21 12:03 11160221
drwxr-xr-x 2 ed root 0 2016-02-22 14:02 11260222
drwxr-xr-x 2 ed root 0 2016-03-06 18:16 11360306
drwxr-xr-x 2 ed root 0 2016-03-07 14:33 11460307
drwxr-xr-x 2 ed root 0 2016-03-08 14:57 11560308
drwxr-xr-x 2 ed root 0 2016-03-09 13:48 11660309
drwxr-xr-x 2 ed root 0 2016-03-10 11:24 11760310
drwxr-xr-x 2 ed root 0 2016-03-11 13:51 11860311
drwxr-xr-x 2 ed root 0 2016-03-12 16:04 11960312
drwxr-xr-x 2 ed root 0 2015-11-22 17:02 12051122
drwxr-xr-x 2 ed root 0 2015-11-25 19:14 12151125
drwxr-xr-x 2 ed root 0 2015-11-29 17:42 12251129
drwxr-xr-x 2 ed root 0 2015-11-30 16:53 12351130
drwxr-xr-x 2 ed root 0 2015-12-05 16:35 12451205
drwxr-xr-x 2 ed root 0 2015-12-07 16:53 12551207
drwxr-xr-x 2 ed root 0 2015-12-08 14:05 12690102

Annoyingly, the first three digits are not in ascending order of date, perhaps because the firmware recycles numbers previously used for now-deleted directories.

The year digit 9 in the last directory (12690102) came from the camera’s default 2009 startup date. You set the camera’s clock by editing its configuration file and rebooting that sucker, which I hadn’t done when I got a new Fly6 as a warranty replacement for the old one; apparently the battery shook itself loose after half a year of riding.

Deleting the directories created last November and December goes a little something like this:

rm -rf /mnt/video/Fly6/DCIM/???51[12]*

You probably want to dry-run that with a directory listing command (perhaps ls -al) just to be sure it will wipe out what you want and nothing else.

Within each directory, the file names follow a more rigid hhmmnnnn format:

• hh = hour
• mm = minute
• nnnn = ascending sequence number

Which produces a set of files like this:

ll /mnt/video/Fly6/DCIM/11960312/
total 6.6G
-rwxr-xr-x 1 ed root 607M 2057-09-06 19:40 13120005.AVI
-rwxr-xr-x 1 ed root 810M 2057-09-06 19:40 13190006.AVI
-rwxr-xr-x 1 ed root 962M 2057-09-06 19:40 13290007.AVI
-rwxr-xr-x 1 ed root 573M 2057-09-06 19:40 13390008.AVI
-rwxr-xr-x 1 ed root 523M 2057-09-06 19:40 13470009.AVI
-rwxr-xr-x 1 ed root 596M 2057-09-06 19:40 13570010.AVI
-rwxr-xr-x 1 ed root 672M 2057-09-06 19:40 14070011.AVI
-rwxr-xr-x 1 ed root 716M 2057-09-06 19:40 14150012.AVI
-rwxr-xr-x 1 ed root 505M 2057-09-06 19:40 14250013.AVI
-rwxr-xr-x 1 ed root 497M 2057-09-06 19:40 14350014.AVI
-rwxr-xr-x 1 ed root 221M 2057-09-06 19:40 14450015.AVI

The NAS drive does not, for reasons I cannot explain, record the actual file creation timestamp; touch-ing the file afterward does update the timestamp correctly. So it goes.

The camera attempts to write the files in 10:00 minute chunks, but, because it deletes files (or, perhaps, entire directories) one-by-one in FIFO style, the actual file duration / size seems limited by the space made available by the deletions. The default 8 GB MicroSD card has something like 6.6 GB available and holds a bit under two hours of video; I should bump that to a 16 GB card to get a complete record of longer rides.