Re: Video Coding Puzzle
Jim Leonard <[email protected]>
| Newsgroups | gmane.comp.video.xine.codec.devel |
|---|---|
| Message-ID | <[email protected]> |
Mike Melanson wrote: > We are hoping to form a clearer expression of some of the decoding > algorithms before releasing the source code. What follows is a description > of a peculiar function that almost seems to have some DCT-like properties. Maybe it's a block slant transform? (Similar to DCT but much faster math) > The technology targets a Pentium 120 MHz CPU as a nominal > platform. Is it possible for this platform to decode DCT-type data in > real-time if the resolution is low enough? These games liked to use > resolutions around 320x165. Considering that I ran the video of WC4 perfectly on a Pentium 120, I'd say yes :-) I still have my P120 if you need me to do testing on exactly that platform. As for the general case answer to your question, I remember decoding MPEG-1 VCD files on my P120 without skipping frames as long as I didn't decode audio. If I tried to decode video+audio, the player dropped B frames to keep up. This was in windows with a player that directly supported decoding YUV data to a video overlay (I had a good card at the time) so I consider my recollection a "true" account of what a P120 can do with MPEG-1 (ie. there was no YUV->RGB conversion or unnecessary data copying to slow things down). I also seem to remember that anything higher than VCD (352x240/288) was impractical to play. On a side note: Unless my memory is playing tricks on me, I recall playing WC3 on an AMD 386/40MHz and the video played fine too, occaisionally stuttering because my CDROM drive at the time was only 1X (150K/s) while the datarate of the WC3 video required up to 180K/s at points. If it wasn't my 386/40 then maybe it was my 486/66 that I upgraded to a year later... but in both cases WC3 didn't require a Pentium to decode the video. -- 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 sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com