[Spice-devel] [PATCH v5 00/20] Add GStreamer support for video streams

[Francois Gouget]

On Wed, 2 Sep 2015, Fabio Fantoni wrote:
[...]
> I tried latest gstreamer patches and seems difficult understand if
> really use gstreamer, is yes you did a good work the graphic quality and
> performance seems same/similar of without streaming.

The 'gstreamer_encoder.c:' lines are a sure way to know if the GStreamer 
encoder is being used or not. Of particular interest are these lines:

(/usr/sbin/xl:11883): Spice-Debug **: gstreamer_encoder.c:1237:gst_encoder_encode_frame: video format change: width 0 -> 20, height 0 -> 20, format 0 -> 8

-> This is a new video stream for a video of size 20x20. So most of what 
   you saw as being a video was most likely not that tiny video stream.


(/usr/sbin/xl:11883): Spice-Debug **: gstreamer_encoder.c:803:construct_pipeline: GStreamer pipeline: appsrc name=src format=2 do-timestamp=true ! videoconvert ! vp8enc name=encoder ! appsink name=sink

-> This is the resulting GStreamer pipeline.

(/usr/sbin/xl:11883): Spice-Debug **: gstreamer_encoder.c:1336:gst_encoder_client_stream_report: client report: 0/5 drops in 234ms margins video 400/401 audio 4294967295/4294967295 bw 0.019/0.022Mbps

-> This is the corresponding bandwidth usage. It's not out of line 
   considering the video size.


Now the real question is why is Spice thinking a 20x20 area is a video? 
This may be because you set streaming-video=all but it does have trouble 
like that some times. That's unrelated to how the video stream is being 
encoded though.

Whether Spice correctly detects the video being played depends on the 
video player being used and also on the SpiceDeferredFPS and 
EnableSurfaces settings.

You can try:
    Option "SpiceDeferredFPS" "24"
    #Option "EnableSurfaces" "false"
or
    #Option "SpiceDeferredFPS" "24"  
    Option "EnableSurfaces" "false"


-- 
Francois Gouget <fgouget at codeweavers.com>