Computer scientist Updated +Created
Electrical resistivity and conductivity Updated +Created
FFmpeg filter graph Updated +Created
Filter graphs are a thing of great beauty. What an amazingly obscure domain-specific language, but which can produce striking results with very little!!!
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
'
which creates a graph:
                              +--------+
[sine=frequency=500]--->[a]-->|        |
                              | amerge |-->[atrim]-->[output]
[sine=frequency=1000]-->[b]-->|        |
                              +--------+
and plays 500 Hz on the left channel and 1000 Hz on the right channel for 2 seconds.
So we see the following syntax patterns:
  • sine, amerge and atrim are filters
  • sine=frequency=500: the first = says "araguments follow"
    • frequency=500 sets the frequency argument of the sine filter
    • for multiple arguments the syntax is to separate arguments with colons e.g. sine=frequency=500:duration=2
  • ;: separates statements
  • [a], [b]: sets the name of an edge
  • ,: creates unnamed edge between filters that have one input and one output
A list of all filters can be obtained ith:
ffmpeg -filters
and parameters for a single filter can be obtained with:
ffmpeg --help filter=sine
Related question: stackoverflow.com/questions/69251087/in-ffmpeg-command-line-how-to-show-all-filter-settings-and-their-parameters-bef
TODO dump graph to ASCII art? trac.ffmpeg.org/wiki/FilteringGuide#Visualizingfilters mentions a -dumpgraph option, but haven't managed to use it yet.
Bibliography:
Field (mathematics) Updated +Created
A ring where multiplication is commutative and there is always an inverse.
A field can be seen as an Abelian group that has two group operations defined on it: addition and multiplication.
And then, besides each of the two operations obeying the group axioms individually, and they are compatible between themselves according to the distributive property.
Basically the nicest, least restrictive, 2-operation type of algebra.
@cirosantilli/_file/python/python/getitem.py Updated +Created
Fresnel equations Updated +Created
Racing game Updated +Created
Role-playing video game Updated +Created
Sandbox game Updated +Created
Text-based game Updated +Created
Although Ciro Santilli is a big fan of plaintext files and of Vim, not so for games. Games must be easy to understand since they are just a toy.
Tilesets to the rescue!
Video game decompilation Updated +Created
Asymmetric warfare Updated +Created
Autism Updated +Created
Cold War Updated +Created
List of wars Updated +Created
Ciro's Edict #6 / Misc advances Updated +Created
Made the website navbar and article lists more mobile friendly. Main motivation: improvised demos to people I meet IRL!
tket Updated +Created
Domain of an elliptic curve Updated +Created

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