On Tue, Oct 05, 2004 at 02:57:55AM +0200, Martin Samuelsson wrote: > On Tuesday 05 October 2004 02:02, Steven M. Schultz wrote: > > Most TV shows are in increments of 30 minutes. At 25 fps that's 45000 > > frames. Store the data in 45000 frame files. When it comes time to > > age the data you can simply delete entire files that are older than > > the specified threshold. The first file that remains may have some > > frames that need to be skipped over (but with a fixed record format > > you can use something simple like 'dd' to do that). > > Exactly. With a headerless fixed record format you could do the equivalent of > tail -F videofile | lavplay, replacing videofile at fixed intervals. Presto, > circular recording buffer! A better implementation would allow seeking past > the beginning of the latest file, and so on. That's just some pseudoscript. > > Such a format would open possibilities to mix different streams in real time, > making it possible to toy with overlay graphics and stuff. Personally, I use DV for that. And not just any DV, but a hacked-up version of my DV codec from FFMPEG that can use different bitrates. The default framesize for PAL is 144000 bytes, this can be cut down to ~130000 bytes without any quality loss. If you want more -- I think 30000 bytes per frame should still watchable, which gives you a bitrate of 9600bps and all the benefits of sequentialable DV :-)
Of course, don't expect Premiere to happily load it :-) Thanks, Roman. ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
