Framerate on mosaic of multiple RTSP stream

[Tim-Philipp Müller]

On Fri, 2013-01-25 at 20:26 -0800, adrien Schwartzentruber wrote:

Hi,

> My goal is to display a mosaic of different RTSP stream. This is my
> gst-launch command line to create this : 
> gst-launch videomixer name=mixer ! queue ! ffmpegcolorspace ! autovideosink
> uridecodebin uri=rtsp://localhost:8554/stream ! queue ! videoscale
> add-borders=TRUE ! video/x-raw-yuv, width=200, height=200 ! videobox top=-1
> left=-1 ! mixer. uridecodebin uri=rtsp://localhost:8555/stream ! videoscale
> add-borders=TRUE ! video/x-raw-yuv, width=200, height=200 ! videobox top=-1
> left=-200 ! mixer. uridecodebin uri=rtsp://localhost:8556/stream ! queue !
> videoscale add-borders=TRUE ! video/x-raw-yuv, width=200, height=200 !
> videobox top=-201 left=-1 ! mixer. uridecodebin
> uri=rtsp://localhost:8556/stream ! queue ! videoscale add-borders=TRUE !
> video/x-raw-yuv, width=200, height=200 ! videobox top=-201 left=-201 !
> mixer.
> 
> I observed that the framerate of the display is very low (like 1 image / 2
> sec).
> 
> Someone can explain to me why ? 

That usually means there's a problem with latency reporting/handling
somewhere in the pipeline. frames are dropped at the think because the
sink thinks they're way too late, because it doesn't know about the
latency. You can check if this is what's happening with

   GST_DEBUG=basesink:5 gst-launch...

You might also want to try videomixer2, it might handle things
marginally better (but I think there are still some known issues with
live streams).

Cheers
 -Tim