I know that in some cases, it's harder to compress efficiently interlaced videos. I've made some tests - though I can't remember how empty lines where filled - where I realized that jpeg where way bigger when interlaced.
In a C# project I'm doing, it's possible from the C++ Runtime side to interlace videos by just skipping odd or even lines when capturing. That means that I can almost double the speed of the image processing algorithm, opening the possibility to get a decent frame rate on smaller devices.
But is this possible to do anything that would make benefit in compression step? Currently, with the H.263 method I'm using, a 20 seconds, 640x480, 15fps video take up to 3-4 minutes to encode on the average device I'm using.
So, the question is: Is there an approach to modify frames either by interlacing them or any linear lossy way so that it wouldn't be -more- hard to compress than before this modification?