Phil Wherry: greetings.
drofnasw: O.K., BoyGenius, how'd you do it?
Phil Wherry: Used an image toolkit under Linux 
and a little script to assemble the images at the 
same time the archive is being updated.
Phil Wherry: The code's pretty hard to follow, but 
you can look at it if you'd like: type

cat /usr/local/bin/archive-animate

in a terminal window.
drofnasw: Could we offer a range of sizes, say 2, 4, 6 
hours? Easily (translation: w/o imposing upon too much 
more of your time)?
Phil Wherry: yeah, that's really simple (have a 
look at the code and you'll see how trivial that 
is...)
drofnasw: Well, I'm not sure that the code would make 
much sense right now -- I'm pretty drugged on pain 
killers! (Back pain!!!)
Phil Wherry: got it. well, it's easy (the first line of 
the script reads "HOURS=2" if that gives you any 
idea). What time ranges did you want to offer?
drofnasw: I'm just makin' up stuff, but how 'bout 2, 4, 
6, 8 -- who do we appreciate? Phil, Phil, Phil!!!
Phil Wherry: very amusing. i was thinking 
something like 2, 6, 12, 24. The 24-hour 
sequence takes over a minute to generate, so I 
think that's the longest we should do.
drofnasw: Really, I wasn't joking! Your suggestion 
sounds good too. Can you make it happen so I can 
take a test drive?
Phil Wherry: sure. i'll edit the code and it'll 
generate the images in the next archiving pass 
(about five minutes from now).
drofnasw: Try 2, 4, 6, 8.
Phil Wherry: ok
drofnasw: and 12. 24 will feature too much nightime!
Phil Wherry: true, though it will always loop 
completely smoothly.
drofnasw: Huh?
Phil Wherry: the step from the last frame back to 
the first one will be smooth since it's at 
approximately the same time of day.
Phil Wherry: code changes made; it'll generate 
the animations in the next archive pass - just a 
little under 2 minutes from now.
drofnasw: What are the URLs?
Phil Wherry: they'll be of the form last-n-hours 
(where n=2, 4, 6, 8, 12)
drofnasw: I would have guessed the output files would 
end up in the "archive" directory -- isn't that where the 
heavy lifting gets done?
drofnasw: Is it showtime?
Phil Wherry: they can - I was just trying to 
declutter the archive directory.
Phil Wherry: yes, they're there.
drofnasw: O.K., hang on ...
drofnasw: Dude, that's AWESOME! 12 hours neatly 
covered the entire day!
Phil Wherry: great. want me to put a 24-hour 
batch into the next run just for comparison?
drofnasw: Why not? Do the files get overwritten? If so, 
then how often?
Phil Wherry: they get updated every 10 minutes 
just like the archives. the overwrite process is 
smart enough that it won't break things if 
someone is accessing a file as it's being 
overwritten.
drofnasw: On the 5s?
Phil Wherry: correct. another update is just about 
to begin.
Phil Wherry: it'll take about 2 minutes to get to 
the 24-hour image though
Phil Wherry: i'll message you when I see the file 
appear
drofnasw: If someone is accessing a file, does it not get 
updated?
Phil Wherry: no, it's updated - you just get the file 
that exists at the moment you START to access 
it.
Phil Wherry: (i.e. if i access it at 18:04:59, it's 
updated at 18:05:03, and you access it at 
18:05:08, i'll get the old file in its entirety and 
you'll get the new one in its entirety)
Phil Wherry: it's still thinking on the 24-hour run.
Phil Wherry: ok, it's there. last-24-hours.gif
Phil Wherry: question: would it make more sense 
to put the images in the archive directory? trivial 
change if you'd like them there.
drofnasw: How big is the avg. size of the smaller 
versions we're generating? Could we also generate 
shorter duration mid-size versions?
Phil Wherry: -rw-r--r--    1 root     root      1358217 
Feb 19 18:26 last-12-hours.gif
-rw-r--r--    1 root     root       212096 Feb 19 
18:25 last-2-hours.gif
-rw-r--r--    1 root     root      2271058 Feb 19 
18:27 last-24-hours.gif
-rw-r--r--    1 root     root       438109 Feb 19 
18:25 last-4-hours.gif
-rw-r--r--    1 root     root       669131 Feb 19 
18:25 last-6-hours.gif
-rw-r--r--    1 root     root       904439 Feb 19 
18:25 last-8-hours.gif

Phil Wherry: anywhere between 212K and 2.3M 
depending on number of hours.
Phil Wherry: larger versions are definitely 
possible; it just doesn't look that much better in a 
larger format.
drofnasw: No, but you can easily read the date/time!
drofnasw: Hold that thought for now. Just curious.
Phil Wherry: we can try it if you'd like. which 
versions should we attempt this with?
drofnasw: Like I said, just exploring possibilities. The 
first 4-hr movie I made was nearly 1.5 MB!
Phil Wherry: let me try it w/ the 2- and 4-hr 
versions then. 
drofnasw: Re: directory, which makes more sense?
Phil Wherry: doesn't matter to me, really; no 
strong opinion.
drofnasw: I say leave it as it is. If for no other reason 
than the URL is shorter.
Phil Wherry: yeah, the larger versions are 
definitely big. the 320x240 version of 
last-2-hours is 716K.
Phil Wherry: new filename format is: 
last-n-hours-resolution (i.e. 
last-2-hours-320x240.gif)
drofnasw: Is it online?
Phil Wherry: yes. 12- and 24-hour 160x120 
images are still generating but everything else is 
there now.
Phil Wherry: 
last-2-hours-160x120.gif
last-2-hours-320x240.gif
last-4-hours-160x120.gif
last-4-hours-320x240.gif
last-6-hours-160x120.gif
last-8-hours-160x120.gif

Phil Wherry: (my 320x240 version of last-4-hours 
is 1.5 MB too)
drofnasw: VERY NICE!
drofnasw: What is the frame delay you're using?
Phil Wherry: good deal. i think i'm using 5 ms.
Phil Wherry: or maybe 50 - not sure what the 
units are.
drofnasw: I think it's a little faster than I used.
Phil Wherry: It was just the first figure I tried; 
looked good so I stuck with it.
drofnasw: Could you double-check the value? I 
believe in truth in advertising!
Phil Wherry: it's specified in the script as "-delay 
5" - I just don't know what the underlying units 
are.
drofnasw: O.K.
Phil Wherry: it's in centiseconds - so it's 50ms or 
about 20 frames/second.
Phil Wherry: want to crank the rate up or down a 
bit? easy to do...
drofnasw: I used 20/100 sec (2/10 sec) -- twice as 
slow as my original setting.
Phil Wherry: so one-quarter of the current 
speed? glad to try that if you'd like.
Phil Wherry: do we need different delays 
depending on how long the sequence is? that 
speed on the 24-hour image could be pretty dull.
drofnasw: A li'l slower is better for the shorter runs, I 
think.
Phil Wherry: ok. How about 200ms spacing on 
the 2, 4, 6, 8-hr runs, 100ms on the 12-hour and 
we'll leave the 24-hour run alone at 50ms?
drofnasw: Sure. It's mostly guesswork!
drofnasw: I'm watching the 24-hour run -- seems O.K. 
at faster speed....
Phil Wherry: i'm doing a run now to try out new 
timings...
drofnasw: Some guy in UT just asked me if he can run 
a USB camera 50-60 ft. Beats me! All I know is our 
camera sits at the end of a 75-ft. video cable!
Phil Wherry: I doubt you'll get USB to work at that 
kind of distance.
drofnasw: So recommend low-tech?
Phil Wherry: or an ethernet camera
Phil Wherry: New filenames:
last-12-hours-160x120-100ms-frames.gif
last-2-hours-160x120-200ms-frames.gif
last-2-hours-320x240-200ms-frames.gif
last-24-hours-160x120-50ms-frames.gif
last-4-hours-160x120-200ms-frames.gif
last-4-hours-320x240-200ms-frames.gif
last-6-hours-160x120-200ms-frames.gif
last-8-hours-160x120-200ms-frames.gif

drofnasw: This is AWESOME!!! I KNEW you could 
do it!!!
Phil Wherry: just had to find the right tools. i 
definitely think we've got the most sophisticated 
version of this project in the world at this point.
drofnasw: No question, we are. 1!!!
drofnasw: No. 1
drofnasw: Like Bill said, an inspiration to everyone!
drofnasw: 12 looks good!
Phil Wherry: well, it'd be a lot more inspiring if he 
got the pointers to the dials out there in a public 
place!
drofnasw: Agreed! That sort of prep should have been 
done months ago!
drofnasw: 6 looks good!
Phil Wherry: what's the current ETA for a public 
release?
drofnasw: Tomorrow.
Phil Wherry: that's when he's planning to put the 
pointers on his site?
drofnasw: http://www.planetary.org/mars/earthdial/
Phil Wherry: (or were you saying you'd have the 
image sequences on there tomorrow)
drofnasw: Map is there; no dials, except in list form. 
Re: our ani's, they'll be linked before this boy crashes 
tonight -- way too cool to sit on!!!
Phil Wherry: ah, looks like they did some work 
on it today actually.
drofnasw: yes.
Phil Wherry: neat! well, this should make the 
pages a bit more entertaining. i'm declaring the 
code done unless other changes are needed.
drofnasw: They need to bag the frames, though -- they 
could use the screen real estate!
drofnasw: And more demanding for the server! 
Remember, you opened Pandora's Box!
Phil Wherry: not sure i follow...
drofnasw: Well, I'm sure this will put a strain on 
YOUR Internet bandwidth....
Phil Wherry: it shouldn't be a big deal; i don't 
expect this to generate tons of traffic.
drofnasw: We'll see....
Phil Wherry: if so, there are ways (rate-limiting) 
to deal with it so it doesn't cause problems.
drofnasw: One more time, please give me a complete 
list of the current filenames.
Phil Wherry: 
last-12-hours-160x120-100ms-frames.gif
last-2-hours-160x120-200ms-frames.gif
last-2-hours-320x240-200ms-frames.gif
last-24-hours-160x120-50ms-frames.gif
last-4-hours-160x120-200ms-frames.gif
last-4-hours-320x240-200ms-frames.gif
last-6-hours-160x120-200ms-frames.gif
last-8-hours-160x120-200ms-frames.gif

Phil Wherry: (you can just do a "ls" command in 
the /home/html/webcam/earthdial directory, of 
course)
drofnasw: Honestly, how much time did you spend on 
this?
Phil Wherry: once i found the sequencing 
software, it took about a half-hour to write. i've 
spent much longer chatting with you about it than 
I did writing it in the first place.
drofnasw: Very funny!
Phil Wherry: true though.
Phil Wherry: to give you an idea, here's the code 
in its entirety:
HOURS=$1
IMAGESIZE=$2
DELAY=$3
touch -d "${HOURS} hours ago" /tmp/timeflag
/usr/local/bin/convert -resize ${IMAGESIZE} 
-compress lzw -delay ${DELAY} `find 
/home/html/webcam/earthdial/archive -name 
"*.jpg" -newer /tmp/timeflag` /tmp/anim.gif
mv /tmp/anim.gif 
/home/html/webcam/earthdial/last-${HOURS}-ho
urs-${IMAGESIZE}-${DELAY}0ms-frames.gif

drofnasw: This will really put us on the map, so to 
speak. I would be stunned if anyone equals this 
accomplishment!
Phil Wherry: well, it's definitely pretty neat.
drofnasw: Again, elegant in its simplicity!
Phil Wherry: that's Unix for you - lots of little 
modular tools that can be glued together in 
interesting ways.
drofnasw: Would it have made sense for ED Central to 
do what we're doing, only for EVERYONE?
Phil Wherry: quite possibly. but i suppose part of 
the fun of the project is seeing how different 
groups take on the challenge of getting it to 
work.
drofnasw: O.K., I can't keep a secret!
Phil Wherry: so I see. :-)
Phil Wherry: i'm going to have to sign off but i'll 
check the site out later to see how you integrated 
the links.
drofnasw: O.K. Thank you so much for makin' this 
happen!!!!!
Phil Wherry: glad to help...
drofnasw: Say "Hi!" to Holly for me. I'll look for you 
later....
Phil Wherry: Sounds good. Holly's actually on 
travel right now; back a week from Saturday.
Phil Wherry: signing off now; take care!
Phil Wherry signed off at 7:21:52 PM.