> > rate: video is 7 frames behind > > rate: video is 7 frames behind > > I don't think that being 7 frames behind doesn't mean that you've lost > them Exactly. It just says video and audio are slightly out of sync, with a difference of 7 frames (~ 0.25 seconds @ 30 fps). The 7 frames are missing, but you don't lose 7 frames for every line. The second line just says you are still 7 frames behind, not that you've lost 7 more frames (maybe I should make that less verbose...). The timing isn't very exact as the v4l api doesn't allow to provide timestamps for the captured frames, so streamer/xawtv uses gettimeofday right after the SYNC ioctl. > I'm getting 320x240 at the default 10 frames/second. The key to > reducing the warning messages you and I see was reducing the rate the > video was written to the drive, so I guess writing more compressed, like > MPEG (I have yet to check out the recommended mp1e) or getting SCSI > drives will help. With MJPEG/MPEG cpu time is the bottleneck, with uncompressed data the hard disk. /me reaches 320x240 @ 25 fps (mjpeg compressed, P3/450) without major problems. Neverless streamer has a few known issues: * It can't deal very good with lost frames, it can't do tricks like stuffing the next frame twice it has lost one. That's a problem if you want to record at full framerate. A workaround is to use a slightly lower rate, say 24 instead of 25 fps (for PAL). If you lose a single frame now and then, streamer can deal with that much better because there is one "unused" frame per second which can be used to make video catch up if it lags behind. * It can't handle floating point frame rates (like 29.97). * Audio recording seems to have problems with some drivers/cards. It requires working select() support. Sometimes it leaves the dsp device alone quite some time, triggering recording overruns if the driver uses a small dma buffer. Thats at least the issues I'm aware of. Gerd -- Get back there in front of the computer NOW. Christmas can wait. -- Linus "the Grinch" Torvalds, 24 Dec 2000 on linux-kernel
