Hello, Sorry for the late answer. I have trouble to keep up-to-date with this list mails. However, I hope the waiting period is worth if this solution works:
First of all, have you made sure the webcam can feed frames at 30 fps? If you're forcing a framerate the camera cannot provide, you're likely to get faulty videos, or no video at all. It's not that it's too high or too low --sometimes the camera is limited to a discrete range of rates (for instance, the webcams we are using can give 30 fps and 24 fps but not 25). If the camera *can* provide such framerates, you may be experiencing the same problem as we do: apparently the "libconvert" used in Ubuntu has some kind of bug (or is terribly inefficient --which may be considered a bug anyway--) and can't keep up with the high framerate, causing a significantly high amount of frames to be dropped. I guess using such a "huge" frame size at such high rate does not help either (even though a powerful machine should be able to cope with that). We are kind of experimenting with Intel i7 cores for various reasons (not that you need such a "beast" for a capture agent), and even though the machine is *only* recording some video from the camera, there will be frames dropped (which shouldn't happen in such a powerful machine). Try the following pipeline in "customProducer" (I don't really know what "rate" is for, so I'm taking it out; I don't think you need a queue before ffmpegcolorspace, even though it doesn't harm either): v4l2src device=/dev/webcam ! queue ! jpegdec ! videorate ! video/x-raw-yuv, width=1920, height=1080, framerate=30/1 ! ffmpegcolorspace I hope it works. Please do test it first using gst-launch (it may need some minor adjustments) and let me (us) know how it goes. Best regards Rubén 2011/10/24 Edmore Moyo <[email protected]> > Good day, > > > I am a newbie to the Matterhorn community. We are experiencing a similar > issue as the one stated here : * > http://opencast.3480289.n2.nabble.com/Matterhorn-users-duration-issue-problem-with-audio-video-sync-tt6355528.html > * > > *Was this issue ever resolved?* We have tried encoding our presenter file > with *ffmpeg* 0.6, 0.7.6 and 0.8.2 but the duration of the presenter file > is always significantly less than before encoding. This is not the case > with the other files though their duration remains the same. > > This has led us to suspect that this is an issue to do with the source > file generated or some sort of camera incompatibility. We are using a > logitech c910 camera and the following config settings: > > capture.device.Presenter.customProducer=v4l2src device=/dev/video0 ! > image/jpeg,width=1920,height=1080,framerate=30/1,rate=30 ! queue ! jpegdec ! > queue ! ffmpegcolorspace > > capture.device.Presenter.flavor=presenter/source > > capture.device.Presenter.outputfile=Presenter.mpg > > capture.device.Presenter.src=/dev/video0 > > capture.device.Presenter.type=CUSTOM_VIDEO_SRC > > > We were initially using : > > capture.device.Presenter.customProducer=v4l2src device=/dev/video0 ! > image/jpeg,width=1920,height=1080,*framerate=15/1,rate=15* ! queue ! jpegdec > ! queue ! ffmpegcolorspace > > but on viewing the source file using *mediainfo *it was not showing a > duration and the frames per second were 0.00fps > > Regards, > > Edmore Moyo > > UCT > > > > ### > > UNIVERSITY OF CAPE TOWN > > This e-mail is subject to the UCT ICT policies and e-mail disclaimer > published on our website at > http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 > 21 650 9111. This e-mail is intended only for the person(s) to whom it is > addressed. If the e-mail has reached you in error, please notify the > author. If you are not the intended recipient of the e-mail you may not > use, disclose, copy, redirect or print the content. If this e-mail is not > related to the business of UCT it is sent by the sender in the sender's > individual capacity. > > ### > > _______________________________________________ > Matterhorn-users mailing list > [email protected] > http://lists.opencastproject.org/mailman/listinfo/matterhorn-users > >
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