GStreamer saving video capture to file: intermittent freezes

[marc3 at rechte.fr]

(continuation)

I discovered that when uploaded to youtube (and also to Google drive), 
the video plays OK !

You'll find it here unaltered: http://195.167.234.228/capture.mp4

This capture is from a Logitech C920 camera. It has among other 
features, a monitor stream. When I capture both streams (monitor sent to 
an X window, the other to a file), the problem disappears !

With this command the video is OK:
$ gst-launch-1.0 -v -e uvch264src device=/dev/video0 name=src 
auto-start=true \
     src.vidsrc ! queue ! 
video/x-h264,width=1280,height=720,framerate=30/1 ! h264parse ! mp4mux ! 
filesink location=capture.mp4 \
     src.vfsrc ! queue ! 
video/x-raw,format=\(string\)YUY2,width=320,height=240,framerate=10/1 ! 
xvimagesink sync=false

Marc