GNOME Bugzilla – Bug 691250
Videos created with thoggen play back with choppy audio
Last modified: 2017-07-13 12:41:41 UTC
I have a series of Theora/Vorbis videos I created from DVDs using thoggen. (I own the DVDs.) When I play the videos in totem, the audio skips every 10 seconds or so. I find the same thing happens when I play the videos using "gst-launch playbin..." and (on Mac OS X) VLC. What is strange is that the videos play fine with mplayer. I thought perhaps that totem was skipping the video to keep it synchronized with the audio, but the synchronization in mplayer does not seem to degrade as the video plays. It does not seem to be an issue of CPU speed, as top indicates totem is occupying around 20% of my cycles. I could provide a copy of one of the videos out of band if needed.
(In reply to comment #0) > I find the same thing happens when I play the videos using > "gst-launch playbin..." and (on Mac OS X) VLC. -> GStreamer
I think we'd need to see a sample file. It might have been caused by a combination of lots of jitter on the input side and a lack of audiorate in Thoggen and overzealous discont behaviour by vorbisenc.
I have uploaded an example to http://www.flyn.org/random/CuriousGeorge.ogv. You will need to enter the username and password "gstreamer" and "gstreamer". This video is actually one of the better behaved ones (I chose it because it is smaller than the others). I hear the first skip at 0:32. I also submitted an inquiry to gstreamer-devel: http://lists.freedesktop.org/archives/gstreamer-devel/2013-January/038740.html I did some more testing with mplayer, and it seems that the video and audio do seem to become more out-of-sync as the video plays, so my first post was not entirely accurate. Back to Gstreamer, using "alsasink sync=false" causes the skips to go away (but the audio and video tracks diverge).
Sorry no one ever got around to looking into this. The example file seems gone now, and I don't seem to have a local copy anywhere. So closing this for now. If it's still a problem, I'm sure someone will file a bug again sooner or later, but I don't think Thoggen is still in use :) There have also been quite a few bug fixes in the last few years. Please feel free to re-open if you still have the sample file.