Indeo 4.x and 5.x
Jim Leonard <[email protected]>
| Newsgroups | gmane.comp.video.xine.codec.devel |
|---|---|
| Message-ID | <[email protected]> |
I was always under the impression that Indeo 4.x and 5.x were wavelet-based -- I was wrong! They use a block slant transform, similar (if not identical) to a Haar transform. From a Usenet posting: AFAIK Indeo 4.x uses 8x8 block slant transform. It is less optimal for compression then DCT, but can be implemented without multiplications - big advantage for an old 486 CPU (16*16bit imul takes up to 26 cycles on i486, shift - only 2 cycles). Apparently, slant transform is the most efficient one from the transforms not based on sinusoids. So, Indeo 4.x is pretty much the regular block transform + motion compensation kind of codec. It's just the transform is sort of "wavelet-like". Does anyone have any additional information on "block slant" transforms? I would love to learn more, but all I've found on the web is http://rkb.home.cern.ch/rkb/AN16pp/node113.html#112 -- Jim Leonard ([email protected]) World's largest electronic gaming project: http://www.MobyGames.com/ A delicious slice of the demoscene: http://www.MindCandyDVD.com/ Various oldskool PC rants and ramblings: http://www.oldskool.org/ ------------------------------------------------------- This SF.Net email is sponsored by: GNOME Foundation Hackers Unite! GUADEC: The world's #1 Open Source Desktop Event. GNOME Users and Developers European Conference, 28-30th June in Norway http://2004/guadec.org