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I read some where it was possible to create a gif by adding frames to it in a browser. Does that mean on the server you can add frames to it by using cat?

Are there other file types that are so simple to work with? What would be something good to do to better understand file headers that is very simple and would help explore sending data over an arduino ( which is of course a seperate issue! ).

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up vote 2 down vote accepted

Gifs cannot be manipulated in that way by appending. It's disappointing, I know. I'd written a detailed explanation of the file format here, but Wikipedia explains it better. This is why appending with cat doesn't work.

There aren't many "simple" formats, but I'd take a bet that .bmp is one of the simplest, containing a semi-raw pixel array and metadata.

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To create an animated GIF using command line, I would use the excellent command line tools from the package Imagemagick:

convert -delay 10 *.gif animation.gif
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obviously this is not a relevant answer – Prospero Nov 18 '12 at 10:42

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