On Tuesday 05 October 2004 02:02, Steven M. Schultz wrote: > On Tue, 5 Oct 2004, Martin Samuelsson wrote: > What a word! But yes, that's better than streamable :-)
Mmm, words. They are fun to play with. :) > Circular files. Not sure if they're well suited to video processing. I don't think they are. Used in a continuos timeshifter, though... The circular file approach would be a strictly watch-and-forget business a la a non-recording TiVo. Recording and storing is another issue. > There's 10 hours of TV that's actually worth watching? :) I'm lucky Nah. > if I can find more than an hour a week that's actually worth taking > the time to watch ;) It's the principle of the thing. :) You remember, fifteen minutes after your favorite show ended, that you wanted to watch it. Rewind 75 minutes and start watching. Or 80, to see if there's any new, spiffy commercial you haven't seen before! :) (You most likely had the tuner set to a very boring channel that doesn't broadcast your favorite show, but that's not the point. :) > If you have a easily seekable format (fixed record size) then you > could achieve the effect of circular files fairly easily I think by > storing a fixed number of frames per time-stamp-named files. In Europe > it's a bit simpler than in the US - you've got 25 frames/sec rather > than 30000/1001 frames/sec. I'm already doing this, kind of. I record in chunks of 10000 frames, because those are easy to handle if you write clip lists by hand. "Hm, I want frame 26587 to 37226. That's file 2, frame 6587 to 9999, file 3, frame 0 to 7226." (I later built a script that build them for me. The bliss!) Theoretically, I could record in chunks of, say, 60 seconds, feed new files to lavplay as they are finished by lavrec, and delete old files. It would give a minimum of one minute lag, but it would be usable. Not taking into account that lavplay can't be fed new files once started, then. > 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. /Martin ------------------------------------------------------- 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
