Forums > MaxMSP

Encode/Compress a list for storing

June 22, 2011 | 5:23 pm

Hello,

I just wonder if there is a way to somehow compress a long list to fewer elements for storing at a coll. Is there an algorithm to encode/decode a long list?
Many thanks

Vangelis


June 22, 2011 | 10:03 pm

I guess that depends on what your lists might be made up of. Also, is there a reason you don’t want to store them in the [coll] as they are?

Here’s an idea that turns everything into one symbol using [regexp]:

– Pasted Max Patch, click to expand. –

June 23, 2011 | 9:19 am

i guess because they are too long.

of course one could merge several numbers into a symbol such as "symbol 12345 54321 99999 77777".


June 25, 2011 | 12:38 am

Hello,

many thanks for your replies. I guess I have to be more precise. I am trying to capture/store data from the Kinect. That means an update of 18 points with three (XYZ) values, 30 times a sec.
I am receiving data as OSC so I turn them to ASCII numbers (atoi) first.
I can use a coll object to store them but playback is slow for an unknown reason to me even if I use metro:1
I got in to GDIF http://gdif.3075338.n2.nabble.com/ (based on FTM)
but for a minute of capture data the size of the file is around 4mb and needs at least 5 min to be loaded back to the algorithm.
Another option is to use a OSC recorder and I ve found one (java) that does not work, again not sure why.
So, I was thinking if there is a way to compress the data before storing in order to produce smaller data sets. I am not sure there is a benefit to turn them to symbols first…is there?
Finally I got into this :http://www.maxobjects.com/?request=compress&operateur=AND&id_format=0&id_plateforme=0&Submit=OK
and tested the a-hglide object and sadam.lzo
with no success (not very informative help files)

Any ideas?
Many thx


June 25, 2011 | 4:12 am

Storage of large quantities of numerical data is exactly what Jitter’s for.

Here’s an example of storing and playing back one minute’s worth of 18 xyz coordinates at 30 fps.

– Pasted Max Patch, click to expand. –

June 29, 2011 | 9:48 pm

Thanks Christopher. I will try to mod it to store lists of 25 elements and see if that works fast on large amount of data


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