#for each 3 frames in the source we only keep 1
mkdir frames3; cd frames3
#unfortunately this video has a lot of unnecessary noise added to it to represent water reflection caustics or something so we brutally denoise it with hqdn3d
time mplayer ../nucleostream-wip.mp4 -vf-add hqdn3d=30:30:10:10 -vf-add framestep=3 -x 480 -y 270 -vf-add scale -vo jpeg
cd ..
#using the same color map for all frames reduces file size and flickering
convert frames3/00000060.jpg -geometry 480 -dither none -colors 250 colormap250.gif

#i'm doing the conversion in imagemagick so i can compare consecutive frames. delay 1x15 is 1/15th of a second
#pixel values closer than 5% are considered "the same" and set to transparent in the next frame
start=1 step=1 end=737; time convert -limit memory 2GiB -delay 1x15 `seq -f "frames3/%08g.jpg" $start $step $end` -geometry 480 +repage -coalesce +dither -map colormap250.gif -fuzz "5%" -layers OptimizeTransparency nucleostream_fuzz5_250c.gif


# you may get an error like this:
# convert-im6.q16: cache resources exhausted `frames3/00000583.jpg' @ error/cache.c/OpenPixelCache/4083.
# see https://github.com/ImageMagick/ImageMagick/issues/396
# imagemagick pukes if you don't have enough memory available in the system config. 
# i guess it loads all frames into ram first and then does its thing
# even though i set files to 1000 i still have a max of 768? dunno, it works for this 737-frame animation at least...
#
#$ cat /etc/ImageMagick-6/policy.xml
#<policymap>
#  <policy domain="resource" name="memory" value="2GiB"/>
#  <policy domain="resource" name="map" value="2GiB"/>
#  <policy domain="resource" name="width" value="16KP"/>
#  <policy domain="resource" name="height" value="16KP"/>
#  <!-- <policy domain="resource" name="list-length" value="128"/> -->
#  <policy domain="resource" name="area" value="512MB"/>
#  <policy domain="resource" name="disk" value="8GiB"/>
#  <policy domain="resource" name="file" value="1000"/>
#  <!-- <policy domain="resource" name="thread" value="4"/> -->
#  <!-- <policy domain="resource" name="throttle" value="0"/> -->
#  <!-- <policy domain="resource" name="time" value="3600"/> -->
#  <!-- <policy domain="coder" rights="none" pattern="MVG" /> -->
#  <!-- <policy domain="module" rights="none" pattern="{PS,PDF,XPS}" /> -->
#...
#
#$ identify -list resource
#Resource limits:
#  Width: 16KP
#  Height: 16KP
#  List length: 18.446744EP
#  Area: 512MP
#  Memory: 2GiB
#  Map: 2GiB
#  Disk: 8GiB
#  File: 768
#  Thread: 4
#  Throttle: 0
#  Time: unlimited