As far as my job goes, which includes the responsibility for improving an MPEG encoder, MPressionist plays an additional role that I want to mention briefly.

Writing new code to improve an MPEG encoder is challenging, but not that challenging. It's not as difficult, as say, sending 4 live human beings to the moon in a rocket-powered aluminum tin-can and getting them back to earth safely.

What is difficult or sometimes impossible, is changing a person's belief system. And that includes mine. So one of the main roles that MPressionist plays in my life is forcing me to come to terms with my beliefs about how well our MPEG encoder performs. It also helps me to determine what is feasible; because if we don't know what is feasible, we can't deliver on promises made to customers.

I think you'll find some places where 29.97i NTSC is promised at 4.5 Mbs with Hollywood DVD quality. Even with heavy filtering, I think this barely feasible; at least with the algorithms I've seen running in the MPEG encoders I play with. And because I don't think its feasible, we don't make that promise in MegaPEG.X; instead we provide a gamut of alternatives, which includes spatial and temporal downsampling, so that you can get the picture quality out that you want.

I never would have arrived at these conclusions without MPressionist. I figured that if a rock-video shot on 35mm film with Steadicam and cranes at 30fps (on what is probably a 5M budget) is encoded at 7-9 Mbs 29.97i, with copious amounts of filtering, then it is doubtful that a camcorder sequence shot on a handheld/tripod mounted Sony 3CCD prosumer camera and edited in FCP is going to be able to EXCEED that. I mean you can go on and believe whatever you want, but my conclusions are based on working backwards from a finished product that looks superb.

If you wanted to sum up our philosophy here at Digigami, it would be: no artifacts.

That does not mean that our encoder does not produce artifacts. It means that we give you a complete toolset to get your project into the required bitbudget WITHOUT artifacts. And you get to choose what the tradeoffs are.

Every time there's a piece of footage that makes our encoder barf, minutes later I come face to face with it in MPressionist and am forced to re-examine my beliefs about our techniques. In the long run, the more times we fail in this regard the better our encoder will be.