Mathieu Jacomy is currently experimenting a type of graph rendering using a technic called “Hillshading”, a demo is accessible here https://observablehq.com/d/7d19c2d05caf9fb2 . The idea of this concept is to add information to enhance the readability of the graph, especially when there is condensed clusters of nodes.

The current script is working mostly in javascript with D3.js. I wanted to find a way to do it without any JS, locally in my computer. Then I remember a wonderful tool called GMIC that can do a lot of advanced image processing.

Got to work on this website https://psenough.github.io/shader_summary/ that try to gather all graphical live coding events performed in the past.

Basically, for people that don’t know, it’s live coding performance done, sometime as a competition, sometime as a jam, where folks create real time graphics stuff.

One of the common tool used is Bonzomatic , it’s a simple application that use OpenGL to render a rectangle that fit to the application screen and then you can live edit the Framgment Shader that determine what should be the color of the pixel.

(Using Windows PowerShell, adapt for UNIX bash shouldn’t be a big issue)

Record a live stream

So something nice with youtube-dl is like you can ask not to download the media but to fetch for the media link :

>> youtube-dl -g https://www.youtube.com/watch?v=RJt01u4yrLQ
https://r2---sn-h0jeened.googlevideo.com/videoplayback?expire=1[...]

If you use that for a twitch channel that is streaming live, it returns you the HLS stream.

>> youtube-dl -g https://www.twitch.tv/farore_de_firone
https://video-weaver.ber01.hls.ttvnw.net/v1/playlist/CpkEQusnrcdffNI3[..]MA2c4.m3u8

It by default binds to the best quality video, but you can check and select all format available using -F

Update: Since a while, youtube-dl isn’t as powerful as it is. Fortunatelly another fork exists : yt-dlp . Use this instead

Youtube recently got this “chapter” concept where it fragment a long video with chapters. I think this data might be parsed from the description of the video done, as they already parse any timestamp available for a while now.

Thanks to youtube-dl, we can download thena video and the metadata which now contains this chapter data.