The textures, cubemaps, volumes, videos, and music are all the iChannels from ShaderToy.com. The cubemaps are laid out as 6 textures.
I don't know about the license, but all credit goes to ShaderToy and/or the source of those files. I got these files from this site: https://shadertoyunofficial.wordpress.com/2019/07/23/shadertoy-media-files/ so credit to them too.