GStreamer saving video capture to file: intermittent freezes

[Thiago Santos]

On 04/15/2015 06:22 AM, marc3 at rechte.fr wrote:
> (continuation)
>
> I discovered that when uploaded to youtube (and also to Google drive), 
> the video plays OK !
Do you have a link to this same file below on google drive or youtube?
>
> You'll find it here unaltered: http://195.167.234.228/capture.mp4
"gst-launch-1.0 filesrc ! qtdemux ! fakesink silent=false -v" to show 
something wrong in the timestamps. While the dts follow smoothly and the 
duration is constant, the pts jumps a few times and it matches the times 
that the video freezes on screen.

There is something wrong with pts/dts handling here.

Did you capture this using which version of gstreamer?

Do you have a GST_DEBUG=6 log of this capture? It should help verifying 
that qtmux receives the correct pts/dts or if they are already wrong 
since the beginning.

Not sure if related yet, but there is 
https://bugzilla.gnome.org/show_bug.cgi?id=740575 that could have some 
impact here.

> 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

Does the error still happen if you remove the vfsrc branch? Just curious.

>
> Marc
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-- 
Thiago Sousa Santos
Senior Multimedia Engineer, Open Source Group
Samsung Research America - Silicon Valley