Yeah, Clearly PNG isn't appropriate for real-time playback or anything like that. I mainly use it for archiving. I also use uncompressed when I need real-time capture, manipulation, or playback.
But while storage is cheap, it isn't free. A PNG will typically give me a much smaller, but lossless, version of rendered content if I need to transport it to someone. The compression/uncompression time gets pretty minimal when compared to the time savings when files are being copied over a WAN.
I really wish we had a uniform Y'CbCr equivalent. Huffyuv is good, but DirectShow only. There are near-lossless things like M-JPEG, but I want mathematically lossless.
A good JPEG-LS implementation would almost be perfect. Decent compression, and wickedly fast encode/decode. Certainly could be handed in real time for any SD application, and probably for some HD.
My Book:
http://www.benwaggoner.com/books.htm
Cleaner e-book:
http://www.cmpbooks.com/cleaner/
