It simply dumps the pixel values without any optimizations as whatever is the default color model of the video format you use. E.g. the PIC image format is just a dump of one frame in Quicktime (or BMP on Windows) and a file set to "None" is basically just a sequence of these dumped buffers without any fancies. So yes, in a way there is "no CoDec" involved beyond some routine telling whatever encoder/ player is used to pass through the data unchanged.
I see. So there's 'somewhat' a codec for just telling the player, 'this is how to decode the video', but not really anything fancy. I'm also going to take it that the None Codec is 100% uncompressed. I was getting a 2GB file for a few seconds of video, and only a few MB for another lossless codec that I'm sure does use compression.
I was getting a 2GB file for a few seconds of video, and only a few MB for another lossless codec that I'm sure does use compression.
Correct. There's a way to check in AE if a losless codec changed the footage during rendering: put the original footage in a comp, add the rendered footage and apply the Difference blen mode. The differences will appear.
But it really should be okay with a lossless codec. Think of zipping a long work processor document. The file size is smaller, but when you unzip it,you fully expect every letter, number and punctuation mark to be present an in the proper places. That's a lossles codec.