compute QoS with lost frame when streaming

[Maxime Louvel]

Hi everyone,

I want to compute the perceived QoS when streaming a video over a lossy
network.
To do that I'm streaming a video over a wireless network and I record the
video sent and the video received.

Here is the pipeline I have used (here I use an input stream but I could
use webcam) :

# on the server :
gst-launch -e filesrc location=some_moivie.mp4 ! decodebin !
ffmpegcolorspace ! queue ! videorate ! video/x-raw-yuv,framerate=5/1 !
ffenc_mpeg2video quantizer=4 gop-size=1 ! tee name=l ! queue ! mpegtsmux !
rtpmp2tpay ! udpsink host=192.168.0.10 port=5001 l. ! queue ! filesink
location=videosrc.mpeg

# on the client:
gst-launch -e udpsrc port=5001 caps="application/x-rtp, media=video,
encoding-name=MP2T-ES" ! rtpmp2tdepay ! mpegtsdemux ! tee name=t ! queue !
ffdec_mpeg2video ! ffmpegcolorspace ! xvimagesink t. ! queue ! filesink
location=videodst.mpeg

Due to packet losses some frames are missing in the video received
(videodst.mpeg), which is what I expected :)

Then I want to compute a QoS measure to compare the two videos.
I want to use SSIM that compares frames one by one.
Since some frames are missing on the received video, this is not so easy.

My questions are then :

- is there a gstreamer element that would put some dummy frame when one is
missing ? With such element the two videos would have the same number of
frames
- how can I know when a frame is missing in the received video ?

sorry if this is not the right place to ask these questions
thank you very much for your time

Maxime

-- 
Maxime Louvel
web page : https://sites.google.com/site/mlouvel/
linkedin : http://fr.linkedin.com/in/mlouvel
address : 5400-B ridge oak drive
               Austin, Texas, 78731
               USA
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